REMA patches
Jobst Brandt
shop today, I was greatly dismayed to see that the ancients of REMA
are gone and that the new generation is from the same mentality as the
representative whom I met at InterBike two years ago.
That man believed in drying the ruber cement completely and not
removing the celophane, and what for if the volatiles that make paches
cure to bcome part of the innertube have already evaporated. The
perforated line on the cellophane is gone so you can't pull it off
because they don't want you to. If you try to pull it off, the patch
comes off with it as it is peeled from one edge instead of from the
center.
As I said, this method of patching leaves a temporary patch that is so
poorly bonded that it can easily be pulle off by hand... or separate
from riding deformation aided by inflation pressure.
I should add that inner tubes are full of a liberal amount of talcum
powder whose purpoae is to prevent internal adhesion when the freshly
made tube is evacuated for packaging. I hope users notice that the
tubes are airless to a degree that is not easily achived after the
tube has been used. This is done by vacuum before packaging. Talcum
powder is always found in partially separated patches, the domed ones,
such that the dome is full of talcum.
Jobst Brandt
David Scheidt
:As I looked at the stock of new REMA Tip Top patches at the bicycl
:shop today, I was greatly dismayed to see that the ancients of REMA
:are gone and that the new generation is from the same mentality as the
:representative whom I met at InterBike two years ago.
:That man believed in drying the ruber cement completely and not
:removing the celophane, and what for if the volatiles that make paches
:cure to bcome part of the innertube have already evaporated. The
I'm waiting for you to explain the chemistry of that. The volatiles
are there to attack the srface the cement is applied to. The reaction
that occurs is that sulphur cross-links the rubber of the tube to the
rubber of the cement to the specially prepared face gum of the patch.
Hexane or trichloroethylene is not involved in the reaction. That's
why you let it evaporate first. You don't need to worrry about the
rubber in the cement vulcanizing to the tube before the repair is
installed, because it requires activation -- which is supplied by the
specially prepared face gum of the repair unit. YOu can allow the
cement to dry for days, or a month, if you care to, and the repair
will stick to it just fine.
:perforated line on the cellophane is gone so you can't pull it off
:because they don't want you to. If you try to pull it off, the patch
:comes off with it as it is peeled from one edge instead of from the
:center.
:As I said, this method of patching leaves a temporary patch that is so
:poorly bonded that it can easily be pulle off by hand... or separate
:from riding deformation aided by inflation pressure.
I've patched a few thousand tires and tubes, on everything from bicycles
to cars, trucks and earthmoving equipment. I have never had one
single failure of a patch, using the methods specified by the repair
manufacturer. And every supplier of cemented patches and repair units
specifies allowing the solvent to evaporate. Every single one,
without exception.
--
sig 17
DirtRoadie
> As I looked at the stock of new REMA Tip Top patches at the bicycl
> shop today, I was greatly dismayed to see that the ancients of REMA
> are gone and that the new generation is from the same mentality as the
> representative whom I met at InterBike two years ago.
FYI - it is now 2010, at least on the calendar that I use which is
calibrated in earth years.
Read the first comment here by someone using the pen name "Jobst
Brandt"
http://groups.google.com/group/rec.bicycles.tech/msg/f156f26d825a98e3
DR
Jobst Brandt
>> As I looked at the stock of new REMA Tip Top patches at the bicycle
>> shop today, I was greatly dismayed to see that the ancients of REMA
>> are gone and that the new generation is from the same mentality as
>> the representative whom I met at InterBike two years ago.
>> That man believed in drying the rubber cement completely and not
>> removing the cellophane, and what for if the volatiles that make
>> patches cure to become part of the inner-tube have already
>> evaporated.
> I'm waiting for you to explain the chemistry of that. The volatiles
> are there to attack the surface the cement is applied to. The
> reaction that occurs is that sulphur cross-links the rubber of the
> tube to the rubber of the cement to the specially prepared face gum
> of the patch. Hexane or trichloroethylene is not involved in the
> reaction. That's why you let it evaporate first. You don't need to
> worrry about the rubber in the cement vulcanizing to the tube before
> the repair is installed, because it requires activation -- which is
> supplied by the specially prepared face gum of the repair unit. YOu
> can allow the cement to dry for days, or a month, if you care to,
> and the repair will stick to it just fine.
I suppose you missed the item citing how van der Waals forces are
involved in adhesion. You might review that because repeating it is
tedious, there being many fine points.
>> The perforated line on the cellophane is gone so you can't pull it
>> off because they don't want you to. If you try to pull it off, the
>> patch comes off with it as it is peeled from one edge instead of
>> from the center.
>> As I said, this method of patching leaves a temporary patch that is
>> so poorly bonded that it can easily be pulled off by hand... or
>> separate from riding deformation aided by inflation pressure.
> I've patched a few thousand tires and tubes, on everything from
> bicycles to cars, trucks and earthmoving equipment. I have never
> had one single failure of a patch, using the methods specified by
> the repair manufacturer. And every supplier of cemented patches and
> repair units specifies allowing the solvent to evaporate. Every
> single one, without exception.
To make up for that I have seen a similar number of failed patches
from people who followed the "let the glue dry" procedure and found a
way to cleanly remove these failures and replace them with patches
that could not be removed and did not leak. I think my example of the
REMA man at InterBike two years ago is a perfect example of why one
should not follow their write-up.
Jobst Brandt
Tim McNamara
<e3f556b5-5531-4407...@k11g2000vbf.googlegroups.com>,
DirtRoadie <DirtR...@aol.com> wrote:
The relevance of the year being what?
--
That'll put marzipan in your pie plate, Bingo.
thirty-six
> As I looked at the stock of new REMA Tip Top patches at the bicycl
> shop today, I was greatly dismayed to see that the ancients of REMA
> are gone and that the new generation is from the same mentality as the
> representative whom I met at InterBike two years ago.
Just BUY a new repair kit, don't look and criticise. BUY a can of
lighter fluid. Follow instructions, finish by burnishing (or using a
stitcher) or clamp it for ten minutes if you want to be clever about
it.
>
> That man believed in drying the ruber cement completely and not
> removing the celophane, and what for if the volatiles that make paches
> cure to bcome part of the innertube have already evaporated. The
> perforated line on the cellophane is gone so you can't pull it off
> because they don't want you to. If you try to pull it off, the patch
> comes off with it as it is peeled from one edge instead of from the
> center.
>
> As I said, this method of patching leaves a temporary patch that is so
> poorly bonded that it can easily be pulle off by hand... or separate
> from riding deformation aided by inflation pressure.
Doesn't happen.
Stephen Bauman
> The perforated
> line on the cellophane is gone so you can't pull it off because they
> don't want you to. If you try to pull it off, the patch comes off with
> it as it is peeled from one edge instead of from the center.
I've got about a dozen F0 (16 mm) patches left in the box of 100 that I
purchased about a year ago. I was debating whether to buy another box or
wait until next year. My order for a new box will be placed tomorrow
morning.
About 25% of the patches have a faulty perforation that does not break
apart, when folding the patch. I've learned to test the perforation
before removing the foil. If the perforation is faulty, I'll use scissors
to cut a snip from either side of the cellophane. After the patch is
applied, I'll stretch the patch while holding the cellophane on either
side snip. The cellophane will split in two. I can then remove the
cellophane from the center of the patch to the outside edge. The center
to outside removal, prevents the patch from pulling off the tube.
Hopefully, they have not substituted plastic for cellophane like some of
Rema's competitors.
Stephen Bauman
Jay Beattie
Patch failure is frequently associated with poor surface preparation.
You would have to do some investigation before claiming a particular
patch failure had anything to do with whether the vulcanizing fluid
was wet or dry at the time of patch application. -- Jay Beattie.
DirtRoadie
> In article
> <e3f556b5-5531-4407-9452-0c6efc5f8...@k11g2000vbf.googlegroups.com>,
>
> DirtRoadie <DirtRoa...@aol.com> wrote:
> > On Sep 16, 2:24 pm, Jobst Brandt <jbra...@sonic.net> wrote:
> > > As I looked at the stock of new REMA Tip Top patches at the bicycl
> > > shop today, I was greatly dismayed to see that the ancients of REMA
> > > are gone and that the new generation is from the same mentality as the
> > > representative whom I met at InterBike two years ago.
>
> > FYI - it is now 2010, at least on the calendar that I use which is
> > calibrated in earth years.
>
> > Read the first comment here by someone using the pen name "Jobst
> > Brandt"
> >http://groups.google.com/group/rec.bicycles.tech/msg/f156f26d825a98e3
>
> The relevance of the year being what?
Ask Jobst. He MAY understand, even if you don't.
DR
andre...@aol.com
I don't quite understand the problem with patching. I usually go to
walmart cause I can get a can of cement instead of the little tubes
that are crap. I also get a hand full of whatever patches they have.
Sometimes they have car patches and sometimes they have bike patches.
Either way, I cut them all into little pieces cause I find them too
big. I only patch at home. I carry 3 spare tube and if I get more
flats, I'll tie a knot on the tube. At home, I sand the punctured
area. I mark with a marker the surrounding area where I want to put
the patch. I put glue, wait for it to get almost dry, and apply patch.
They are very hard to remove once installed. I rarely fail at properly
patching a tube. I have one with 6 patches that keeps on going.
Sir Ridesalot
You sure have it in for Rema don't you? It's been almost *FOUR* years
since you posted, " As I related,
the REMA patch representative at InterBike 2005 rolled on a patch
which I readily pulled off again when he handed it to me. In
contrast, after a curing pause (for me that is the next day) the patch
cannot be pulled off without the frying pan heat treatment. "
I really don't know why you have such a problem getting a patch to
stick. I have patched many a tube at the roadside and the patches have
held up for years of further riding.
Cheers from Peter
thirty-six
The patches should last for at least ten years. Should you roll your
tubes tight and get a crease through a patch, you may find that they
crack. The thick red rubber patches of days gone by seem to be
completely immune to this. Can't say about Velox, there all hidden
in tubulars. I've even used a self-made patch out of liquid latex
brushed onto glass. There is no requirement to test, patches stick
and stay stuck when properley applied and then left well alone.
Jobst Brandt
>> As I looked at the stock of new REMA Tip Top patches at the bicycl
>> shop today, I was greatly dismayed to see that the ancients of REMA
>> are gone and that the new generation is from the same mentality as
>> the representative whom I met at InterBike two years ago.
> Just BUY a new repair kit, don't look and criticise. BUY a can of
> lighter fluid. Follow instructions, finish by burnishing (or using
> a stitcher) or clamp it for ten minutes if you want to be clever
> about it.
The cellophane cannot be removed without pulling off the patch as
well. I guess you didn't read my description of the REMA man and his
demonstration that yielded an uncured, readily removeable patch that I
pulled of and hande him when he handed me his "permanently patched
tube".
>> That man believed in drying the ruber cement completely and not
>> removing the celophane, and what for if the volatiles that make
>> paches cure to bcome part of the innertube have already
>> evaporated. The perforated line on the cellophane is gone so you
>> can't pull it off because they don't want you to. If you try to
>> pull it off, the patch comes off with it as it is peeled from one
>> edge instead of from the center.
>> As I said, this method of patching leaves a temporary patch that is
>> so poorly bonded that it can easily be pulle off by hand... or
>> separate from riding deformation aided by inflation pressure.
> Doesn't happen.
Doid happen. Are you saying I'm lying?
>> I should add that inner tubes are full of a liberal amount of
>> talcum powder whose purpoae is to prevent internal adhesion when
>> the freshly made tube is evacuated for packaging. I hope users
>> notice that the tubes are airless to a degree that is not easily
>> achived after the tube has been used. This is done by vacuum
>> before packaging. Talcum powder is always found in partially
>> separated patches (the domed ones) such that the dome is full of
>> talcum.
Jobst Brandt
thirty-six
> Trevor Jeffrey wrote:
> >> As I looked at the stock of new REMA Tip Top patches at the bicycl
> >> shop today, I was greatly dismayed to see that the ancients of REMA
> >> are gone and that the new generation is from the same mentality as
> >> the representative whom I met at InterBike two years ago.
> > Just BUY a new repair kit, don't look and criticise. BUY a can of
> > lighter fluid. Follow instructions, finish by burnishing (or using
> > a stitcher) or clamp it for ten minutes if you want to be clever
> > about it.
>
> The cellophane cannot be removed without pulling off the patch as
> well. I guess you didn't read my description of the REMA man and his
> demonstration that yielded an uncured, readily removeable patch that I
> pulled of and hande him when he handed me his "permanently patched
> tube".
I dont care for the cellophane, it falls off when the patch has been
burnished.
>
> >> That man believed in drying the ruber cement completely and not
> >> removing the celophane, and what for if the volatiles that make
> >> paches cure to bcome part of the innertube have already
> >> evaporated. The perforated line on the cellophane is gone so you
> >> can't pull it off because they don't want you to. If you try to
> >> pull it off, the patch comes off with it as it is peeled from one
> >> edge instead of from the center.
> >> As I said, this method of patching leaves a temporary patch that is
> >> so poorly bonded that it can easily be pulle off by hand... or
> >> separate from riding deformation aided by inflation pressure.
> > Doesn't happen.
>
> Doid happen. Are you saying I'm lying?
Now there's a suggestion worth investigating. Are you lying, Jobst.
Jobst Brandt
>> The perforated line on the cellophane is gone so you can't pull it
>> off because they don't want you to. If you try to pull it off, the
>> patch comes off with it as it is peeled from one edge instead of
>> from the center.
> I've got about a dozen F0 (16 mm) patches left in the box of 100
> that I purchased about a year ago. I was debating whether to buy
> another box or wait until next year. My order for a new box will be
> placed tomorrow morning.
First item: Do they have the perforations on the cellophane?
> About 25% of the patches have a faulty perforation that does not
> break apart, when folding the patch.
It should not break when folding the patch. It is intended to be split
by stretching the installed patch and patched tube. It will curl
outward and can be pulled off to either side at the same time putting
no net pull on the patch.
> I've learned to test the
> perforation before removing the foil. If the perforation is faulty,
> I'll use scissors to cut a snip from either side of the cellophane.
> After the patch is applied, I'll stretch the patch while holding the
> cellophane on either side snip. The cellophane will split in two.
> I can then remove the cellophane from the center of the patch to the
> outside edge. The center to outside removal, prevents the patch
> from pulling off the tube.
I've tried that with meager success, but it can be done, and must be
done with all new REMA patches.
> I hope they have not substituted plastic for cellophane like some of
> REMA's competitors.
Not to worry, these guys are capable of the worst "advances". I have
also thought about that.
Jobst Brandt
thirty-six
It is not a criminal offence to leave the cellophane on, it just shows
you havn't burnished the patch, so your testing may prove your faulty
technique.
Jobst Brandt
I guess you missed the description why the rubber cement must be semi
liquid (gelled) when the patch is applied and why the REMA patches had
a special cellophane cover that could be pulled off a freshly placed
patch.
Jobst Brandt
Jobst Brandt
>> As I looked at the stock of new REMA Tip Top patches at the bicycle
>> shop today, I was greatly dismayed to see that the ancients of REMA
>> are gone and that the new generation is from the same mentality as
>> the representative whom I met at InterBike two years ago.
> Just BUY a new repair kit, don't look and criticise. BUY a can of
> lighter fluid. Follow instructions, finish by burnishing (or using
> a stitcher) or clamp it for ten minutes if you want to be clever
> about it.
The cellophane cannot be removed without pulling off the patch as
well. I guess you didn't read my description of the REMA man and his
demonstration that yielded an uncured, readily removable patch that I
pulled of and handed him when he handed me his "permanently patched
tube".
>> That man believed in drying the rubber cement completely and not
>> removing the cellophane, and what for if the volatiles that make
>> parches cure to become part of the inner tube have already
>> evaporated. The perforated line on the cellophane is gone so you
>> can't pull it off because they don't want you to. If you try to
>> pull it off, the patch comes off with it as it is peeled from one
>> edge instead of from the center.
>> As I said, this method of patching leaves a temporary patch that is
>> so poorly bonded that it can easily be pulled off by hand... or
>> separate from riding deformation aided by inflation pressure.
> Doesn't happen.
Did happen. Are you saying I'm lying?
>> I should add that inner tubes are full of a liberal amount of
>> talcum powder whose purpose is to prevent internal adhesion when
>> the freshly made tube is evacuated for packaging. I hope users
>> notice that the tubes are airless to a degree that is not easily
>> achieved after the tube has been used. This is done by vacuum
>> before packaging. Talcum powder is always found in partially
>> separated patches (the domed ones) such that the dome is full of
>> talcum.
Jobst Brandt
Jobst Brandt
If the patch is properly applied, the volatiles between tube and patch
should be allowed to evaporate. The longer the cellophane remains on
the longer the patch requires to cure to a solid adhesion. That is
why the cellophane was made removable, but the new REMA team is
apparently full of people with your beliefs, reducing the world's best
bicycle tire patches to also-rans.
Stephen Bauman
>
> First item: Do they have the perforations on the cellophane?
>
There's some kind of treatment to make the cellophane slit in a straight
line. I've never seen individual perforations with the naked eye and have
never bothered to look at the cellophane under magnification. I'd assume
scoring the cellophane, rather than perforating it, would provide the
same functionality.
The slit's orientation is important because I want to pull the cellophane
apart lengthwise not crosswise on the patched tube. I'll hold the patch
to the light and can usually see a faint line at an angle to give me a
clue as to the slit's orientation.
>> About 25% of the patches have a faulty perforation that does not break
>> apart, when folding the patch.
>
> It should not break when folding the patch. It is intended to be split
> by stretching the installed patch and patched tube. It will curl
> outward and can be pulled off to either side at the same time putting no
> net pull on the patch.
>
If the direction of the fold is such that the cellophane is on the
outside and if the fold is along the line of the perforation, then the
act of folding will stretch the cellophane and pull it apart. Simple
stretching is not an option because the foil is still attached.
As mentioned above, the slit's orientation on the tube is important. I
stop with a little slit with the ends of the cellophane still intact. I
can peel the patch off the foil by pulling a corner of the cellophane and
I'm certain of the slit's orientation.
Let's also differentiate between creating a slit on the cellophane across
the middle of the patch and removing the two pieces of cellophane. The
folding, whether on the foil or on the tube is to start the slit. Pulling
apart is still necessary to complete the slit.
>> I've learned to test the
>> perforation before removing the foil. If the perforation is faulty,
>> I'll use scissors to cut a snip from either side of the cellophane.
>> After the patch is applied, I'll stretch the patch while holding the
>> cellophane on either side snip. The cellophane will split in two. I
>> can then remove the cellophane from the center of the patch to the
>> outside edge. The center to outside removal, prevents the patch from
>> pulling off the tube.
>
> I've tried that with meager success, but it can be done, and must be
> done with all new REMA patches.
>
I have close to a 100% success rate with the tiny slits I make with the
scissors. Pulling the cellophane apart is slightly different. Whereas a
normally one would pull from the center of the patch to the outer edge,
one starts with an outer edge and pulls to the center and does the same
thing with the slit on the other edge of the cellophane.
I used to use the scissors after the patch was on the tube and the
cellophane would not pull apart. I once missed and cut a nice slit in a
perfectly patched tube. That's why I now start the slit or cut two slits
with the scissors with the foil still on.
Did the instructions note the difference? Is it possible that you just
got a bad batch of patches?
I can imagine that they had a bad run of patches at the Rema factory and
were wondering what to do with them. I can conceive that one of their
sales execs popped up and said something to the effect that he had an
encounter at an Interbike show a few years earlier and knew exactly where
the bad batch of patches should be dumped. :=)
Stephen Bauman
Jay Beattie
>
> - Show quoted text -
No, you said:
". . . I have seen a similar number of failed patches
from people who followed the "let the glue dry" procedure and found a
way to cleanly remove these failures and replace them with patches
that could not be removed and did not leak. I think my example of
the
REMA man at InterBike two years ago is a perfect example of why one
should not follow their write-up."
My point is simply that patch failure frequently results from poor
preparation of the tube surface (failing to fully remove mould
release). You don't know if the people who "let the glue dry" had
patch failures because they let the glue dry or because of poor
preparation. You would have to rule out the latter to confirm the
former. -- Jay Beattie.
DirtRoadie
> >The cellophane cannot be removed without pulling off the patch as
> >well. I guess you didn't read my description of the REMA man and his
> >demonstration that yielded an uncured, readily removable patch that I
> >pulled of and handed him when he handed me his "permanently patched
> >tube".
>
> times.
> I don't know exactly what was wrong with the patching technique of the
> salesman, as I wasn't there*. But you say yourself that you don't
> believe your own patching is fit for use until at least 24 hours after
> patching, so by your own measure, your patching is as defective as
> his.
>
> *Best guesses would be inadequate removal of moulding wax,
> insufficient time for the rubber solution to dry, or insufficiently
> vigourous buffing/stitching.
I do find Jobst's constant self-references annoying (to put it
mildly). He could just as easily be repeating his experience in
sighting the Loch Ness Monster. Fer' chrisssake, he doesn't even know
when the "REMA scandal" took place although he constantly refers to
the time and location. Even his details change. I propose "REMA
Scandal" as a term we can use in the future to avoid having to discuss
the details and avoid Jobst the embarrassment of not keeping his story
straight.
That said, what you have said here is an excellent summary. But I will
add what *I* do from MY experience. I am asking nobody to adopt my
procedures or perspective.
Like you, I let the glue dry before applying a patch. I have not tried
letting it dry for a month as you suggest is possible, but I have
certainly let it dry overnight. That works just fine. Everyone -
Please don't tell me this has not worked fine for ME. It has.
Like JB I do not use a patched tube immediately. That is partially
intentional, but largely because I don't do my patching on the
road.
And if consensus means anything, NOBODY has suggested that applying a
patch to undried glue and using the tube immediately achieves good
results.
DR
Tim McNamara
<5f08ab5e-0438-418b...@g10g2000vbc.googlegroups.com>,
DirtRoadie <DirtR...@aol.com> wrote:
Oh, I did understand, DirtBoy. My question to you- which seemed to
whoosh over your head so I'll make it simpler for you- is "what
difference does it make?"
Tim McNamara
<7a20ca58-5d72-429c...@g10g2000vbc.googlegroups.com>,
DirtRoadie <DirtR...@aol.com> wrote:
> On Sep 17, 8:15 am, Phil W Lee <p...@lee-family.me.uk> wrote:
> > >The cellophane cannot be removed without pulling off the patch as
> > >well. I guess you didn't read my description of the REMA man and
> > >his demonstration that yielded an uncured, readily removable patch
> > >that I pulled of and handed him when he handed me his "permanently
> > >patched tube".
> >
> > We could hardly fail to have read it by now, you've posted it so
> > many times. I don't know exactly what was wrong with the patching
> > technique of the salesman, as I wasn't there*. But you say
> > yourself that you don't believe your own patching is fit for use
> > until at least 24 hours after patching, so by your own measure,
> > your patching is as defective as his.
> >
> > *Best guesses would be inadequate removal of moulding wax,
> > insufficient time for the rubber solution to dry, or insufficiently
> > vigourous buffing/stitching.
>
> I do find Jobst's constant self-references annoying (to put it
> mildly). He could just as easily be repeating his experience in
> sighting the Loch Ness Monster. Fer' chrisssake, he doesn't even
> know when the "REMA scandal" took place although he constantly refers
> to the time and location. Even his details change. I propose "REMA
> Scandal" as a term we can use in the future to avoid having to
> discuss the details and avoid Jobst the embarrassment of not keeping
> his story straight.
Molehill != mountain, DirtBoy. Doesn't matter if it was 2008 or 2005.
Get over yourself.
> That said, what you have said here is an excellent summary. But I
> will add what *I* do from MY experience. I am asking nobody to adopt
> my procedures or perspective.
>
> Like you, I let the glue dry before applying a patch. I have not
> tried letting it dry for a month as you suggest is possible, but I
> have certainly let it dry overnight. That works just fine. Everyone -
> Please don't tell me this has not worked fine for ME. It has.
I let it dry until the thin smear of glue is no longer shiny but it
still slightly tacky. Patch goes on, pressed down with thumb or tire
lever is used to "burnish" the patch which usually also causes the
cellophane to release. Or, if patching at home, I have a press that the
patched tube goes into overnight. I haven't have a patch come loose in
decades.
> Like JB I do not use a patched tube immediately. That is partially
> intentional, but largely because I don't do my patching on the road.
>
> And if consensus means anything, NOBODY has suggested that applying a
> patch to undried glue and using the tube immediately achieves good
> results.
Give it time. ;-) I don't think Trevor has posted to this thread yet.
Tim McNamara
Stephen Bauman <sba...@abt.net> wrote:
> On Fri, 17 Sep 2010 03:53:19 +0000, Jobst Brandt wrote:
>
> >
> > First item: Do they have the perforations on the cellophane?
> >
>
> There's some kind of treatment to make the cellophane slit in a
> straight line. I've never seen individual perforations with the naked
> eye and have never bothered to look at the cellophane under
> magnification. I'd assume scoring the cellophane, rather than
> perforating it, would provide the same functionality.
>
> The slit's orientation is important because I want to pull the
> cellophane apart lengthwise not crosswise on the patched tube. I'll
> hold the patch to the light and can usually see a faint line at an
> angle to give me a clue as to the slit's orientation.
I've never paid the slightest attention to this and have never had a
problem, but it makes some sense that it'd be more convenient to orient
the slit in the cellophane as you describe. Although it really
shouldn't be much of an issue so long as the pull is not perfectly
aligned with the slit. I'll have to pay more attention to this and
experiment with it.
> >> About 25% of the patches have a faulty perforation that does not
> >> break apart, when folding the patch.
> >
> > It should not break when folding the patch. It is intended to be
> > split by stretching the installed patch and patched tube. It will
> > curl outward and can be pulled off to either side at the same time
> > putting no net pull on the patch.
> >
>
> If the direction of the fold is such that the cellophane is on the
> outside and if the fold is along the line of the perforation, then
> the act of folding will stretch the cellophane and pull it apart.
> Simple stretching is not an option because the foil is still
> attached.
>
> As mentioned above, the slit's orientation on the tube is important.
> I stop with a little slit with the ends of the cellophane still
> intact. I can peel the patch off the foil by pulling a corner of the
> cellophane and I'm certain of the slit's orientation.
>
> Let's also differentiate between creating a slit on the cellophane
> across the middle of the patch and removing the two pieces of
> cellophane. The folding, whether on the foil or on the tube is to
> start the slit. Pulling apart is still necessary to complete the
> slit.
Back in the day I was taught to "burnish" the patch with a tire lever to
improve adhesion. Probably not necessary but I still do it. This
usually loosens the cellophane and makes it easy to remove- at least
with the older ones with slits. I don't think I've seen the newer ones
Jobst references.
Wait, I have to correct that. I just opened my most recently purchased
Rema patch kits and I see no indication of a slit in the cellophane. I
think I bought those in late 2009 or early 2010 at REI.
I wonder if a light touch with an X-Acto knife would score the
cellophane without damaging the patch, restoring the slit to make the
cellophane easier to remove.
Tim McNamara
Phil W Lee <ph...@lee-family.me.uk> wrote:
> Jobst Brandt <jbr...@sonic.net> considered 17 Sep 2010 03:44:58 GMT
> the perfect time to write:
>
> >Trevor Jeffrey wrote:
> >
> >>> As I looked at the stock of new REMA Tip Top patches at the
> >>> bicycl shop today, I was greatly dismayed to see that the
> >>> ancients of REMA are gone and that the new generation is from the
> >>> same mentality as the representative whom I met at InterBike two
> >>> years ago.
> >
> >> Just BUY a new repair kit, don't look and criticise. BUY a can of
> >> lighter fluid. Follow instructions, finish by burnishing (or
> >> using a stitcher) or clamp it for ten minutes if you want to be
> >> clever about it.
> >
> >The cellophane cannot be removed without pulling off the patch as
> >well.
>
> Bullshit. I always remove the cellophane without removing the patch.
> But then I've always been working on patches that have been properly
> applied, according to the manufacturers instructions, so peeling the
> cellophane off doesn't lift the patch because the rubber solution is
> dry, not wet. If you press the patch down properly, with a stitcher
> or equivalent, the cellophane practically falls off anyway, since the
> rubber patch and tube get stretched around and the cellophane (being
> far less elastic) separates from it.
Peeling the cellophane from the edge before the patch has cured will
tend to lift the edge of the patch. The adhesion between the cellophane
and the patch is stronger than that between the patch and the tube until
the bond is cured. I use a tire lever to "burnish" the patch after
applying and, like you, I find that usually loosens the cellophane
sufficiently to make it easy to get off. Although I don't recall that I
have yet used one of the "new" Rema patches; I had a stock of the old
patches with slits in the cellophane, but there are only a few left in
the box.
I haven't used a stitcher on a bike patch in probably 15 years; I used
to use one when patching car and truck tires when I worked in a gas
station in high school. There the patch is on the inside and is pushed
against the tire by air pressure while the opposite happens with a bike
tube, so good application is more critical in the latter.
> >I guess you didn't read my description of the REMA man and his
> >demonstration that yielded an uncured, readily removeable patch that
> >I pulled of and hande him when he handed me his "permanently patched
> >tube".
> >
> >>> That man believed in drying the ruber cement completely and not
> >>> removing the celophane, and what for if the volatiles that make
> >>> paches cure to bcome part of the innertube have already
> >>> evaporated. The perforated line on the cellophane is gone so you
> >>> can't pull it off because they don't want you to. If you try to
> >>> pull it off, the patch comes off with it as it is peeled from one
> >>> edge instead of from the center.
> >
> >>> As I said, this method of patching leaves a temporary patch that
> >>> is so poorly bonded that it can easily be pulle off by hand... or
> >>> separate from riding deformation aided by inflation pressure.
> >
> >> Doesn't happen.
> >
> >Doid happen. Are you saying I'm lying?
>
> I'm saying you don't understand what is actually going on when you
> patch a tube. You get around that problem by leaving patched tubes
> for >24 hrs before using them, which is all that rescues you from
> your poor patching technique.
Really. You've seen Jobst patch a tube and examined the finished
product for yourself? I've not see one of yours so I can't judge your
patching technique...
Jobst Brandt
>> First item: Do they have the perforations on the cellophane?
> There's some kind of treatment to make the cellophane slit in a
> straight line. I've never seen individual perforations with the
> naked eye and have never bothered to look at the cellophane under
> magnification. I'd assume scoring the cellophane, rather than
> perforating it, would provide the same functionality.
> The slit's orientation is important because I want to pull the
> cellophane apart lengthwise not crosswise on the patched tube. I'll
> hold the patch to the light and can usually see a faint line at an
> angle to give me a clue as to the slit's orientation.
Not anymore, you don't. REMA has deleted that feature as I
mentioned. They don't believe there should be anything volatile left
in the patch interface if you followed their instructions to let the
glue completely dry. Therefore, the cellophane foil has no function
and is to be left alone after applying the patch.
>>> About 25% of the patches have a faulty perforation that does not break
>>> apart, when folding the patch.
I guess that was the start. Their 10mm patches had no perforations
from the start, making removal of the cellophane difficult but not
impossible if you cut the foil at a convenient location to pull it
apart... but again, REMA now thinks, why remove it.
>> It should not break when folding the patch. It is intended to be split
>> by stretching the installed patch and patched tube. It will curl
>> outward and can be pulled off to either side at the same time putting no
>> net pull on the patch.
> If the direction of the fold is such that the cellophane is on the
> outside and if the fold is along the line of the perforation, then the
> act of folding will stretch the cellophane and pull it apart. Simple
> stretching is not an option because the foil is still attached.
I believe, that the proper way of handling a patch while placing it on
the prepared leak, is to hold the cellophane where its square shape
extends beyond the orange sticky surface. Therefore, it probably
should not be removed before placing the patch.
> As mentioned above, the slit's orientation on the tube is important.
> I stop with a little slit with the ends of the cellophane still
> intact. I can peel the patch off the foil by pulling a corner of
> the cellophane and I'm certain of the slit's orientation.
There ain't no slit no more!
> Let's also differentiate between creating a slit on the cellophane
> across the middle of the patch and removing the two pieces of
> cellophane. The folding, whether on the foil or on the tube is to
> start the slit. Pulling apart is still necessary to complete the
> slit.
>>> I've learned to test the perforation before removing the foil. If
>>> the perforation is faulty, I'll use scissors to cut a snip from
>>> either side of the cellophane. After the patch is applied, I'll
>>> stretch the patch while holding the cellophane on either side
>>> snip. The cellophane will split in two. I can then remove the
>>> cellophane from the center of the patch to the outside edge. The
>>> center to outside removal, prevents the patch from pulling off the
>>> tube.
>>>> I've tried that with meager success, but it can be done, and must
>>>> be done with all new REMA patches.
> I have close to a 100% success rate with the tiny slits I make with
> the scissors. Pulling the cellophane apart is slightly different.
> Whereas a normally one would pull from the center of the patch to
> the outer edge, one starts with an outer edge and pulls to the
> center and does the same thing
with the slit on the other edge of
> the cellophane.
That sounds simple but peeling from side to side easily lifts the
patch as I did with Mr. REMA at the InterBike show.
> I used to use the scissors after the patch was on the tube and the
> cellophane would not pull apart. I once missed and cut a nice slit
> in a perfectly patched tube. That's why I now start the slit or cut
> two slits with the scissors with the foil still on.
> Did the instructions note the difference? Is it possible that you
> just got a bad batch of patches?
As I said, the new patches supplied to the bicycle shop, and some I
bought through mail-order, have no perforations and do not split
manually.
> I can imagine that they had a bad run of patches at the Rema factory
> and were wondering what to do with them. I can conceive that one of
> their sales execs popped up and said something to the effect that he
> had an encounter at an InterBike show a few years earlier and knew
> exactly where the bad batch of patches should be dumped.
What makes you come to the defense of REMA who made clear that the old
guard is gone and the new guard disagrees with the way the the patches
were designed and how they are used.
These are people who do not know what the sand paper is supposed to do
and why.
Jobst Brandt
Arthur Shapiro
I apply Rema patches using a screen door rolling tool to put a lot of pressure
on the newly-installed patch. A couple minutes of rolling will generally
start loosening the cellophane such that it can be easily pulled off without
disturbing the patch.
If it doesn't, by the next day the patch is so firmly affixed that there's no
way the cellophane can pull the patch off while being removed.
A clarification request: is Mr. Brandt asserting that the patch should be
applied while the "glue" is still semi-dry?
Art
Jobst Brandt
You ask because you haven't read the development of this thread. As I
mentioned, van der Waals forces are primary in adhesion. I don't
believe you would use paint that was partially dried for that reason.
When rubber cement is semi-dried, it still has enough fluidity to bond
well with the patch and the removable cellophane was there to allow
the volatiles to escape while when in place it prevented the orange
part of the patch to dry out and no longer adhere to the place it is
to patch.
Because when these patches were designed, allowing the rubber cement
to be only semi-dry, the cellophane cover was designed to split in the
middle and be pulled off to either side to prevent lifting the patch
that was not yet solidly attached, something it would do in an hour or
more. That is why a freshly patched tube should not be ridden, if
possible.
Jobst Brandt
DirtRoadie
> A clarification request: is Mr. Brandt asserting that the patch should be
> applied while the "glue" is still semi-dry?
Yes.
Ben Pfaff
> The perforated line on the cellophane is gone so you can't pull
> it off because they don't want you to. If you try to pull it
> off, the patch comes off with it as it is peeled from one edge
> instead of from the center.
Ah, this explains why I have trouble with that. I've assumed
that there was some trick to removing the foil that I had not yet
mastered.
--
Ben Pfaff
http://benpfaff.org
Jobst Brandt
>> First item: Do they have the perforations on the cellophane?
> There's some kind of treatment to make the cellophane slit in a
> straight line. I've never seen individual perforations with the
> naked eye and have never bothered to look at the cellophane under
> magnification. I'd assume scoring the cellophane, rather than
> perforating it, would provide the same functionality.
> The slit's orientation is important because I want to pull the
> cellophane apart lengthwise not crosswise on the patched tube. I'll
> hold the patch to the light and can usually see a faint line at an
> angle to give me a clue as to the slit's orientation.
Not anymore, you don't. REMA has deleted that feature as I mentioned.
They don't believe there should be anything volatile left in the patch
interface if you followed their instructions to let the glue
completely dry. Therefore, the cellophane foil has no function and is
to be left alone after applying the patch.
>>> About 25% of the patches have a faulty perforation that does not
>>> break apart, when folding the patch.
I guess that was the start. Their 10mm patches had no perforations
from the start, making removal of the cellophane difficult but not
impossible if you cut the foil at a convenient location to pull it
apart... but again, REMA now thinks, why remove it.
>> It should not break when folding the patch. It is intended to be
>> split by stretching the installed patch and patched tube. It will
>> curl outward and can be pulled off to either side at the same time
>> putting no net pull on the patch.
> If> act of folding will stretch the cellophane and pull it apart.
> If the direction of the fold is such that the cellophane is on the
> outside and if the fold is along the line of the perforation, then
> the act of folding will stretch the cellophane and pull it apart.
> Simple stretching is not an option because the foil is still
> attached.
>>>> I've tried that with meager success, but it can be done, and must
DirtRoadie
> These are people who do not know what the sand paper is supposed to do
> and why.
Before it was one poor schmuck. Now its "these people."
The fact of the matter is they do know exactly what the sandpaper is
supposed to do and that is why they include it and recommend using
it.
Jobst's entire existence seems to revolve around his belief that "I
got vision, and the rest of the world wears bifocals."
It is rare for him to describe anything without his standard mantra
that nobody else knows anything.
I am reasonably certain we are only going to see it get worse.
It's quite sad, actually.
DR
Tom Sherman °_°
pseudonym.
--
Tom Sherman - 42.435731,-83.985007
I am a vehicular cyclist.
Jobst Brandt
>> These are people who do not know what the sand paper is supposed to
>> do and why.
> Before it was one poor schmuck. Now its "these people."
> The fact of the matter is they do know exactly what the sandpaper is
> supposed to do and that is why they include it and recommend using
> it.
Now REMA has made the average user as ill informed as they are
themselves by writing instruction that the sand paper is there to
"roughen up" the surface of the tube, rather than to remove the skin
of the tube, that is full of mold release.
> Jobst's entire existence seems to revolve around his belief that "I
> got vision, and the rest of the world wears bifocals."
I think you are working on that scheme in a ridiculous manner.
> It is rare for him to describe anything without his standard mantra
> that nobody else knows anything.
It is you that place yourself in the unknowing position by repeatedly
claiming that my utterances make no sense and are not understandable
even though stated in plain language.
> I am reasonably certain we are only going to see it get worse.
> It's quite sad, actually.
I think those words fit your utterances well.
Jobst Brandt
DirtRoadie
> It is you that place yourself in the unknowing position by repeatedly
> claiming that my utterances make no sense and are not understandable
> even though stated in plain language.
The facts speak for themselves.
As I have pointed out elsewhere, Occam 1, Jobst 0.
DR
Tom Sherman °_°
Bad Idea
> . . . I was greatly dismayed to see that the ancients of REMA
> are gone and that the new generation is from the same mentality as the
> representative whom I met at InterBike two years ago.
>
> removing the celophane, and what for if the volatiles that make paches
> perforated line on the cellophane is gone so you can't pull it off
> because they don't want you to. If you try to pull it off, the patch
> comes off with it as it is peeled from one edge instead of from the
> center.
. . . Just another jobst straw man. Congratulations jobst, you
demonstrated your superior intellect (haw) over a marketing flack.
The compulsive need to deprecate others over such trivia reveals your
stunted humanity. And you eagerly revisit this after two years
without
embarrassment!?! WOW!
I’ve never seen properly cured patches fail, threads of properly
tightened
pedals fail to support their loads, fretting corrosion in a headset,
etc.
Include spokes that push and threads that can’t be hardened, jobst’s
hysterical rants and insults tell everything about his crippled
personality
and his deficient engineering knowledge.
Tom Sherman °_°
> [...]
> . . . Just another jobst straw man.[...]
Just another anonymous sniper. <yawn>
DirtRoadie
> > The facts speak for themselves.
> > As I have pointed out elsewhere, Occam 1, Jobst 0.
>
> Opinion stated as fact. <yawn>
So sorry you are having trouble staying awake.
But when you are done with your nap, care to actually address the
issue and demonstration I have proposed?
DR
Stephen Bauman
> Stephen Bauman wrote:
>
>>>> About 25% of the patches have a faulty perforation that does not
>>>> break apart, when folding the patch.
>
> I guess that was the start. Their 10mm patches had no perforations from
> the start, making removal of the cellophane difficult but not impossible
> if you cut the foil at a convenient location to pull it apart... but
> again, REMA now thinks, why remove it.
>
I wasn't aware that Rema made a 10mm diameter patch. Their website shows
they make 2 round models that are appropriate for bicycle tube use: the
F1 which is 25mm in diameter and the F0 which is 16mm in diameter.
http://www.rematiptop.com/parts.php?sid=4
More importantly, both the F0 as well as the F1 patches have had
perforations. That you admit not having found them, leaves some doubt in
my mind that Rema may have changed their design. That's why I asked
whether or not there was a change in the instructions.
Mr. T. McNamara confirms your observation in a separate thread. I may
have underestimated your observation powers (or overestimated Mr.
McNamara's). :=)
The 25% faulty perforation rate was pretty much the same for the F0 and
the F1 patches. The F0 patches were easier to work around because there
was more cellophane sticking out beyond that patch than with the F1's.
<snip>
>
> I believe, that the proper way of handling a patch while placing it on
> the prepared leak, is to hold the cellophane where its square shape
> extends beyond the orange sticky surface. Therefore, it probably should
> not be removed before placing the patch.
>
So do I. I have not removed the cellophane. I've merely slightly opened
the slit in the center of the patch to verify its orientation. I peel the
patch off the foil with the corner of the cellophane and place the patch
and cellophane on the tube. I'm sorry if this was not clear in my
previous thread.
<snip>
>> I have close to a 100% success rate with the tiny slits I make with the
>> scissors. Pulling the cellophane apart is slightly different. Whereas
>> a normally one would pull from the center of the patch to the outer
>> edge, one starts with an outer edge and pulls to the center and does
>> the same thing
> with the slit on the other edge of
>> the cellophane.
>
> That sounds simple but peeling from side to side easily lifts the patch
> as I did with Mr. REMA at the InterBike show.
>
It's all in the wrist action. When I'm extending the slits I cut on the
cellophane edges, I'm stretching and rotating the patch in its own plane.
N.B. the patch has already been placed on the tube and has been burnished
before I start. I'm also holding the patch to the tube between between
the my thumb and index finger on both hands placed on either side of the
slit's extension. This is to prevent any lifting force from pulling the
patch off the tube.
>> I can imagine that they had a bad run of patches at the Rema factory
>> and were wondering what to do with them. I can conceive that one of
>> their sales execs popped up and said something to the effect that he
>> had an encounter at an InterBike show a few years earlier and knew
>> exactly where the bad batch of patches should be dumped.
>
> What makes you come to the defense of REMA who made clear that the old
> guard is gone and the new guard disagrees with the way the the patches
> were designed and how they are used.
>
That last paragraph was meant in jest. I'm sorry, if you took it
seriously.
I have no knowledge of the inner hierarchy at Rema to positively know
that an old guard was ousted. Do you?
Stephen Bauman
Jobst Brandt
>>>>> About 25% of the patches have a faulty perforation that does not
>>>>> break apart, when folding the patch.
>> I guess that was the start. Their 10mm patches had no perforations
>> from the start, making removal of the cellophane difficult but not
>> impossible if you cut the foil at a convenient location to pull it
>> apart... but again, REMA now thinks, why remove it.
> I wasn't aware that Rema made a 10mm diameter patch. Their website
> shows they make 2 round models that are appropriate for bicycle tube
> use: the F1 which is 25mm in diameter and the F0 which is 16mm in
> diameter.
They don't but they make a seies of oval and rectangular patches other
than the F1-25mm and F0-16mm round patches. My reference to the 10mm
was faulty typing and proof reading. That should have been 16mm and
it has no perforations on the cellophane cover.
http://www.rematiptop.com/parts.php?sid=4
> More importantly, both the F0 as well as the F1 patches have had
> perforations. That you admit not having found them, leaves some doubt in
> my mind that Rema may have changed their design. That's why I asked
> whether or not there was a change in the instructions.
> Mr. T. McNamara confirms your observation in a separate thread. I
> may have underestimated your observation powers (or overestimated
> Mr. McNamara's). :)
> The 25% faulty perforation rate was pretty much the same for the F0
> and the F1 patches. The F0 patches were easier to work around
> because there was more cellophane sticking out beyond that patch
> than with the F1's.
>> I believe, that the proper way of handling a patch while placing
>> it on the prepared leak, is to hold the cellophane where its square
>> shape extends beyond the orange sticky surface. Therefore, it
>> probably should not be removed before placing the patch.
> So do I. I have not removed the cellophane. I've merely slightly
> opened the slit in the center of the patch to verify its
> orientation. I peel the patch off the foil with the corner of the
> cellophane and place the patch and cellophane on the tube. I'm
> sorry if this was not clear in my previous thread.
>>> I have close to a 100% success rate with the tiny slits I make
Call it what you want, the rules have changed.
Jobst Brandt
Jobst Brandt
>>>>> About 25% of the patches have a faulty perforation that does not
>>>>> break apart, when folding the patch.
>> I guess that was the start. Their 10mm patches had no perforations
>> from the start, making removal of the cellophane difficult but not
>> impossible if you cut the foil at a convenient location to pull it
>> apart... but again, REMA now thinks, why remove it.
> I wasn't aware that Rema made a 10mm diameter patch. Their website
> shows they make 2 round models that are appropriate for bicycle tube
> use: the F1 which is 25mm in diameter and the F0 which is 16mm in
> diameter.
They don't but they make a series of oval and rectangular patches other
than the F1-25mm and F0-16mm round patches. My reference to the 10mm
was faulty typing and proof reading. That should have been 16mm and
it has no perforations on the cellophane cover.
http://www.rematiptop.com/parts.php?sid=4
> More importantly, both the F0 as well as the F1 patches have had
> perforations. That you admit not having found them, leaves some doubt in
> my mind that Rema may have changed their design. That's why I asked
> whether or not there was a change in the instructions.
> Mr. T. McNamara confirms your observation in a separate thread. I
> may have underestimated your observation powers (or overestimated
> Mr. McNamara's). :)
> The 25% faulty perforation rate was pretty much the same for the F0
> and the F1 patches. The F0 patches were easier to work around
> because there was more cellophane sticking out beyond that patch
> than with the F1's.
>> I believe, that the proper way of handling a patch while placing
>> it on the prepared leak, is to hold the cellophane where its square
>> shape extends beyond the orange sticky surface. Therefore, it
>> probably should not be removed before placing the patch.
> So do I. I have not removed the cellophane. I've merely slightly
> opened the slit in the center of the patch to verify its
> orientation. I peel the patch off the foil with the corner of the
> cellophane and place the patch and cellophane on the tube. I'm
> sorry if this was not clear in my previous thread.
>>> I have close to a 100% success rate with the tiny slits I make
Call it what you want, the rules have changed.
Jobst Brandt
DirtRoadie
> Jay Beattie <jbeat...@lindsayhart.com> considered Fri, 17 Sep 2010
> claims to have done, the rubber solution was never properly applied to
> the tube in the first place. The most likely reason for that would be
> failure to remove the mould release.
That's one that I find interesting. I have been quite successful
removing patches cleanly, if not easily, using a solvent such as
toluene. I don't recall why I settled on that as a solvent. I think it
was because I saw that in some rubber cement.
It's usually pretty difficult to get the edge started but then becomes
easier when working on the interface using a saturated Q-tip. I have
tried the suggested heat method with minimal success.
Using my method I am not aware of any visible sign of the patch
location after removal.
DR
Gary Young
<snip>
> Did the instructions note the difference? Is it possible that you just
> got a bad batch of patches?
>
Doubtful. I volunteer at a community bikeshop in Rochester, NY. I checked
our stock of Rema patches bought in the last month or so -- no slits. If
it's a bad batch, it's an awfully large batch.
> I can imagine that they had a bad run of patches at the Rema factory and
> were wondering what to do with them. I can conceive that one of their
> sales execs popped up and said something to the effect that he had an
> encounter at an Interbike show a few years earlier and knew exactly
> where the bad batch of patches should be dumped. :=)
>
> Stephen Bauman
Jobst Brandt
>>>>>>> As I looked at the stock of new REMA Tip Top patches at the
>>>>>>> bicycle shop today, I was greatly dismayed to see that the
>>>>>>> ancients of REMA are gone and that the new generation is from
>>>>>>> the same mentality as the representative whom I met at
>>>>>>> InterBike two years ago. That man believed in drying the
>>>>>>> rubber cement completely and not removing the cellophane, and
>>>>>>> what for if the volatiles that make patches cure to become
>>>>>>> part of the inner-tube have already evaporated.
>>>>>> I'm waiting for you to explain the chemistry of that. The
>>>>>> volatiles are there to attack the surface the cement is applied
>>>>>> to. The reaction that occurs is that sulphur cross-links the
>>>>>> rubber of the tube to the rubber of the cement to the specially
>>>>>> prepared face gum of the patch. Hexane or trichloroethylene is
>>>>>> not involved in the reaction. That's why you let it evaporate
>>>>>> first.
>>>>>> You don't need to worrry about the rubber in the cement
>>>>>> vulcanizing to the tube before the repair is installed, because
>>>>>> it requires activation -- which is supplied by the specially
>>>>>> prepared face gum of the repair unit. You can allow the cement
>> No, you said:
>> "... I have seen a similar number of failed patches from people who
>> followed the "let the glue dry" procedure and found a way to
>> cleanly remove these failures and replace them with patches that
>> could not be removed and did not leak. I think my example of the
>> REMA man at InterBike two years ago is a perfect example of why one
>> should not follow their write-up."
>> My point is simply that patch failure frequently results from poor
>> preparation of the tube surface (failing to fully remove mould
>> release). You don't know if the people who "let the glue dry" had
>> patch failures because they let the glue dry or because of poor
>> preparation. You would have to rule out the latter to confirm the
>> former.
> I would contend that if you can remove the patches cleanly, as Jobst
> claims to have done, the rubber solution was never properly applied
> to the tube in the first place. The most likely reason for that
> would be failure to remove the mould release.
You'd better tell that to REMA. Their "expert" demonstrated how to do
it their way rather than the method I described that produced a patch
that cannot be pulled off without substantial heating, a method I
developed to minister to the partially separated patches that came to
my attention.
A freshly place patch on "dry" rubber cement, pulls off as easy as
Scotch tape.
Jobst Brandt
Jobst Brandt
>>> No, you said:
>>> "... I have seen a similar number of failed patches from people
>>> who followed the "let the glue dry" procedure and found a way to
>>> cleanly remove these failures and replace them with patches that
>>> could not be removed and did not leak. I think my example of the
>>> REMA man at InterBike two years ago is a perfect example of why
>>> one should not follow their write-up."
>>> My point is simply that patch failure frequently results from poor
>>> preparation of the tube surface (failing to fully remove mould
>>> release). You don't know if the people who "let the glue dry" had
>>> patch failures because they let the glue dry or because of poor
>>> preparation. You would have to rule out the latter to confirm the
>>> former.
>> I would contend that if you can remove the patches cleanly, as
>> Jobst claims to have done, the rubber solution was never properly
>> applied to the tube in the first place. The most likely reason for
>> that would be failure to remove the mould release.
> That's one that I find interesting. I have been quite successful
> removing patches cleanly, if not easily, using a solvent such as
> toluene. I don't recall why I settled on that as a solvent. I
> think it was because I saw that in some rubber cement.
> It's usually pretty difficult to get the edge started but then
> becomes easier when working on the interface using a saturated
> Q-tip. I have tried the suggested heat method with minimal success.
> Using my method I am not aware of any visible sign of the patch
> location after removal.
I haven't tried solvent and especially toluene, a solvent not found
around my house. I just recall that it has warnings of toxicity:
http://emedicine.medscape.com/article/818939-overview
Jobst Brandt
thirty-six
> On 17 Sep, 04:44, Jobst Brandt <jbra...@sonic.net> wrote:
>
> > Trevor Jeffrey wrote:
> > >> As I looked at the stock of new REMA Tip Top patches at the bicycl
> > >> are gone and that the new generation is from the same mentality as
> > >> the representative whom I met at InterBike two years ago.
> > > lighter fluid. Follow instructions, finish by burnishing (or using
> > > a stitcher) or clamp it for ten minutes if you want to be clever
> > > about it.
>
> > The cellophane cannot be removed without pulling off the patch as
> > demonstration that yielded an uncured, readily removeable patch that I
> > pulled of and hande him when he handed me his "permanently patched
> > tube".
>
> burnished.
>
> > >> As I said, this method of patching leaves a temporary patch that is
> > >> so poorly bonded that it can easily be pulle off by hand... or
> > >> separate from riding deformation aided by inflation pressure.
> > > Doesn't happen.
>
> > Doid happen. Are you saying I'm lying?
>
> Now there's a suggestion worth investigating. Are you lying, Jobst.
Respond here please.
I checked an old tube I havn't used for at least 15 years and none of
three types of patches could be pulled off by hand. Each of them
required a knife to scrape at the edge and lift with clamping action
on the the knife, pieces of patch were removed. The better performers
were the feather edge where the edge remained with greater adherance.
Not one had bubbled and the best performer was not the TipTop but
another feather edge which was all black. This patch also showed
cracking unlike the others, but not sufficient to cause leakage. None
of these were left wet or had the tube abraded (and probably not even
spirit wiped) yet all of them remained secure with little chance of
itchy fingers pulling them off.
Practically, the manufacturers instructions to leave the rubber
solution to dry before applying the patch are therefore fully
servicable.
One thing to note was that I was touching the edge of the face of the
patch when applying it, paper backed patches are easier to avoid this,
but tend to be the thick ones.
thirty-six
> Peeling the cellophane from the edge before the patch has cured will
> tend to lift the edge of the patch.
It's contact adhesive, there is no curing.
> The adhesion between the cellophane
> and the patch is stronger than that between the patch and the tube until
> the bond is cured.
The joint has to be pressed together for the cement to bond, it is not
curing.
> I use a tire lever to "burnish" the patch after
> applying and, like you, I find that usually loosens the cellophane
> sufficiently to make it easy to get off. Although I don't recall that I
> have yet used one of the "new" Rema patches; I had a stock of the old
> patches with slits in the cellophane, but there are only a few left in
> the box.
Yes burnishing works, as would putting the assebly in a g-clamp for 24
hrs.
>
> I haven't used a stitcher on a bike patch in probably 15 years; I used
> to use one when patching car and truck tires when I worked in a gas
> station in high school. There the patch is on the inside and is pushed
> against the tire by air pressure while the opposite happens with a bike
> tube, so good application is more critical in the latter.
The patch is sandwiched by the tube and the cover, it sticks and stays
stuck..
thirty-six
>
> The cellophane cannot be removed without pulling off the patch as
> well.
I dont know what you want to remove it from, the paper or foil
disintigrates when burnishing the patch when it is applied to the
tube.
> I guess you didn't read my description of the REMA man and his
I know you are being a beligerant old fool.
> demonstration that yielded an uncured, readily removable patch that I
> pulled of and handed him when he handed me his "permanently patched
> tube".
>
> >> That man believed in drying the rubber cement completely and not
> >> removing the cellophane, and what for if the volatiles that make
> >> parches cure to become part of the inner tube have already
> >> evaporated. The perforated line on the cellophane is gone so you
> >> can't pull it off because they don't want you to. If you try to
> >> pull it off, the patch comes off with it as it is peeled from one
> >> edge instead of from the center.
> >> As I said, this method of patching leaves a temporary patch that is
> >> so poorly bonded that it can easily be pulled off by hand... or
> >> separate from riding deformation aided by inflation pressure.
> > Doesn't happen.
>
> Did happen. Are you saying I'm lying?
I've asked this before, you seem to have difficulty answering, are you
lying, Jobst?
>
> >> I should add that inner tubes are full of a liberal amount of
> >> talcum powder whose purpose is to prevent internal adhesion when
> >> the freshly made tube is evacuated for packaging. I hope users
> >> notice that the tubes are airless to a degree that is not easily
> >> achieved after the tube has been used. This is done by vacuum
> >> before packaging. Talcum powder is always found in partially
> >> separated patches (the domed ones) such that the dome is full of
> >> talcum.
>
> Jobst Brandt
thirty-six
> We could hardly fail to have read it by now, you've posted it so many
> times.
> I don't know exactly what was wrong with the patching technique of the
> salesman, as I wasn't there*. But you say yourself that you don't
> believe your own patching is fit for use until at least 24 hours after
> patching, so by your own measure, your patching is as defective as
> his.
>
> *Best guesses would be inadequate removal of moulding wax,
> insufficient time for the rubber solution to dry, or insufficiently
> vigourous buffing/stitching.
>
Too much rubber solution or greasy fingers in the joint also come to
mind as the newbies mistakes.
thirty-six
That just shows you didn't abrade or etch the patch area originally.
As you know, it's not absolutely necessary.
thirty-six
Why would a sane person want to remove a fresh patch, sort of defeats
the object?
thirty-six
> >>>> it off because they don't want you to. If you try to pull it
> >>>> off, the patch comes off with it as it is peeled from one edge
> >>>> instead of from the center.
> >>> that I purchased about a year ago. I was debating whether to buy
> >>> another box or wait until next year. My order for a new box will
> >>> be placed tomorrow morning.
> >> First item: Do they have the perforations on the cellophane?
> >>> break apart, when folding the patch.
> >> by stretching the installed patch and patched tube. It will curl
> >> outward and can be pulled off to either side at the same time putting
> >> no net pull on the patch.
> >>> the perforation is faulty, I'll use scissors to cut a snip from
> >>> either side of the cellophane. After the patch is applied, I'll
> >>> stretch the patch while holding the cellophane on either side
> >>> snip. The cellophane will split in two. I can then remove the
> >>> cellophane from the center of the patch to the outside edge. The
> >>> center to outside removal, prevents the patch from pulling off the
> >>> tube.
> >> I've tried that with meager success, but it can be done, and must be
> >> done with all new REMA patches.
> > you havn't burnished the patch, so your testing may prove your faulty
> > technique.
>
> If the patch is properly applied, the volatiles between tube and patch
> should be allowed to evaporate. The longer the cellophane remains on
> the longer the patch requires to cure to a solid adhesion. That is
> why the cellophane was made removable, but the new REMA team is
> apparently full of people with your beliefs, reducing the world's best
> bicycle tire patches to also-rans.
>
> >>> I hope they have not substituted plastic for cellophane like some of
> >>> REMA's competitors.
> >> Not to worry, these guys are capable of the worst "advances". I have
> >> also thought about that.
>
> Jobst Brandt
Your faulty technique only works with thin patches. There is nothing
superlative about Rema patches, they are a brand which less people
have trouble with because they are thin, allowing for faulty
technique. The thin patch means that wet solvent can migrate out, it
is still incorect technique, it cannot be applied to thicker patches.
Jay Beattie
It would be easy to do a controlled experiment. I am down to two
unpatched tubes after a 30 tube patch-a-thon. They were the ones with
the really tiny holes that I have to dunk to find. Once I do, I will
patch one with a wet patch and one with a dry patch and then try to
peel the patch. The only problem is that I am using cheap-o
Performance patches and not Rema -- but they both work by the same
principle. Are there any special rules I should be following with the
wet patch -- like how wet. Really wet or just kind of wet? How long
do I wait before trying the peel. I figure both should get the same
drying time, just to be fair. I know that the wet one would peel right
off because the glue is still wet.-- Jay Beattie.
Stephen Bauman
> Stephen Bauman <sba...@abt.net> wrote:
<snip>
>>
>> The slit's orientation is important because I want to pull the
>> cellophane apart lengthwise not crosswise on the patched tube. I'll
>> hold the patch to the light and can usually see a faint line at an
>> angle to give me a clue as to the slit's orientation.
>
> I've never paid the slightest attention to this and have never had a
> problem, but it makes some sense that it'd be more convenient to orient
> the slit in the cellophane as you describe. Although it really
> shouldn't be much of an issue so long as the pull is not perfectly
> aligned with the slit. I'll have to pay more attention to this and
> experiment with it.
>
If you're not careful you may learn something new every day. :=)
There are loads of tricks and techniques one acquires over the years.
It's very difficult to document them all.
<snip>
>
> Back in the day I was taught to "burnish" the patch with a tire lever to
> improve adhesion. Probably not necessary but I still do it. This
> usually loosens the cellophane and makes it easy to remove- at least
> with the older ones with slits. I don't think I've seen the newer ones
> Jobst references.
>
I tried to describe my technique for patching tubes in detail around 18
months ago on this forum. Burnishing a freshly applied patch was
definitely prominently mentioned. I use a Rema patch kit box - it's got
no sharp edges. Burnishing definitely loosens the cellophane and making
it easier to remove from the patch.
> Wait, I have to correct that. I just opened my most recently purchased
> Rema patch kits and I see no indication of a slit in the cellophane. I
> think I bought those in late 2009 or early 2010 at REI.
>
I did place that order for 100 more F0 patches but not from REI.
Hopefully, my supplier has the old style with the easy slitting
cellophane.
> I wonder if a light touch with an X-Acto knife would score the
> cellophane without damaging the patch, restoring the slit to make the
> cellophane easier to remove.
Been there and done that. My problem was to start a slit without cutting
into the patch. That's why I opted to cut a small slit at the edges of
the cellophane, where I could lift it from the foil and not disturb the
patch or the foil. I also carry a pair of folding scissors as part of my
road repair tools. I've found them to extremely handy in a variety of
situations.
Stephen Bauman
thirty-six
> In article <EtidnZlbjpmI8w7RnZ2dnUVZ_rSdn...@speakeasy.net>,
> Stephen Bauman <sbau...@abt.net> wrote:
>
>
>
> > On Fri, 17 Sep 2010 03:53:19 +0000, Jobst Brandt wrote:
>
> > > First item: Do they have the perforations on the cellophane?
>
> > straight line. I've never seen individual perforations with the naked
> > eye and have never bothered to look at the cellophane under
> > magnification. I'd assume scoring the cellophane, rather than
> > perforating it, would provide the same functionality.
>
> > The slit's orientation is important because I want to pull the
> > cellophane apart lengthwise not crosswise on the patched tube. I'll
> > hold the patch to the light and can usually see a faint line at an
> > angle to give me a clue as to the slit's orientation.
>
> I've never paid the slightest attention to this and have never had a
> problem, but it makes some sense that it'd be more convenient to orient
> the slit in the cellophane as you describe. Although it really
> shouldn't be much of an issue so long as the pull is not perfectly
> aligned with the slit. I'll have to pay more attention to this and
> experiment with it.
>
>
>
> > >> break apart, when folding the patch.
>
> > > It should not break when folding the patch. It is intended to be
> > > split by stretching the installed patch and patched tube. It will
> > > curl outward and can be pulled off to either side at the same time
> > > putting no net pull on the patch.
>
> > outside and if the fold is along the line of the perforation, then
> > the act of folding will stretch the cellophane and pull it apart.
> > Simple stretching is not an option because the foil is still
> > attached.
>
> > As mentioned above, the slit's orientation on the tube is important.
> > I stop with a little slit with the ends of the cellophane still
> > intact. I can peel the patch off the foil by pulling a corner of the
> > cellophane and I'm certain of the slit's orientation.
>
> > Let's also differentiate between creating a slit on the cellophane
> > across the middle of the patch and removing the two pieces of
> > cellophane. The folding, whether on the foil or on the tube is to
> > start the slit. Pulling apart is still necessary to complete the
> > slit.
>
> Back in the day I was taught to "burnish" the patch with a tire lever to
> improve adhesion. Probably not necessary but I still do it. This
> usually loosens the cellophane and makes it easy to remove- at least
> with the older ones with slits. I don't think I've seen the newer ones
> Jobst references.
>
> Rema patch kits and I see no indication of a slit in the cellophane. I
> think I bought those in late 2009 or early 2010 at REI.
>
> cellophane without damaging the patch, restoring the slit to make the
> cellophane easier to remove.
Just rub harder, it'll come off.
>
> --
> That'll put marzipan in your pie plate, Bingo.
thirty-six
> What makes you come to the defense of REMA who made clear that the old
> guard is gone and the new guard disagrees with the way the the patches
> were designed and how they are used.
Where is the document describing the design and use for Tip Top
bicycle patches? Oh hold on, it's in the box.
>
> These are people who do not know what the sand paper is supposed to do
> and why.
What's 'sand paper', what does it do and why?
thirty-six
Ta-da , yep, that's the reason not to leave it wet, the patch slips
off when you stuff th etube back in the tyre.
thirty-six
> Call it what you want, the rules have changed.
>
> Jobst Brandt
Which rules?
Tim McNamara
<b70b1a44-dec3-4e51...@m35g2000prn.googlegroups.com>,
Bad Idea <bad.i...@gmail.com> wrote:
> On Sep 16, 2:24 pm, Jobst Brandt <jbra...@sonic.net> wrote:
> > . . . I was greatly dismayed to see that the ancients of REMA are
> > gone and that the new generation is from the same mentality as the
> > representative whom I met at InterBike two years ago.
> >
> > That man believed in drying the ruber cement completely and not
> > removing the celophane, and what for if the volatiles that make
> > paches cure to bcome part of the innertube have already evaporated.
> > The perforated line on the cellophane is gone so you can't pull it
> > off because they don't want you to. If you try to pull it off, the
> > patch comes off with it as it is peeled from one edge instead of
> > from the center.
>
> . . . Just another jobst straw man. Congratulations jobst, you
> demonstrated your superior intellect (haw) over a marketing flack.
> The compulsive need to deprecate others over such trivia reveals your
> stunted humanity. And you eagerly revisit this after two years
> without embarrassment!?! WOW! Iąve never seen properly cured patches
> fail, threads of properly tightened pedals fail to support their
> loads, fretting corrosion in a headset, etc. Include spokes that push
> and threads that canąt be hardened, jobstąs hysterical rants and
> insults tell everything about his crippled personality and his
> deficient engineering knowledge.
Hi, jim!
Tim McNamara
Tom Sherman °_° <twsherm...@THISsouthslope.net> wrote:
> On 9/17/2010 3:42 PM, Bad Idea Who? wrote:
> > [...]
> > . . . Just another jobst straw man.[...]
>
> Just another anonymous sniper. <yawn>
It's the return of "jim beam" or his doppelganger. Note the gratuitous
invective and ad hominem, faulty polemical analysis, distorted logic and
deficient capitalization and punctuation.
Tim McNamara
<205776a4-7d4b-4c17...@w4g2000vbh.googlegroups.com>,
DirtRoadie <DirtR...@aol.com> wrote:
> On Sep 17, 2:09 pm, Jobst Brandt <jbra...@sonic.net> wrote:
> > It is you that place yourself in the unknowing position by repeatedly
> > claiming that my utterances make no sense and are not understandable
> > even though stated in plain language.
>
> The facts speak for themselves.
> As I have pointed out elsewhere, Occam 1, Jobst 0.
Occam, of course, would disavow your application of his name in such a
misguided way. Have you identified your three experimental errors yet?
Tim McNamara
<a73e774e-e1fd-4b0a...@f26g2000vbm.googlegroups.com>,
DirtRoadie <DirtR...@aol.com> wrote:
> On Sep 17, 2:35 pm, Tom Sherman °_°
>
> > > The facts speak for themselves. As I have pointed out elsewhere,
> > > Occam 1, Jobst 0.
> >
> > Opinion stated as fact. <yawn>
>
> So sorry you are having trouble staying awake. But when you are done
> with your nap, care to actually address the issue and demonstration I
> have proposed?
Do yourself a favor and keep that discussion to one thread, otherwise
you'll lose track.
Tim McNamara
Stephen Bauman <sba...@abt.net> wrote:
> There are loads of tricks and techniques one acquires over the years.
> It's very difficult to document them all.
Indeed. I've been at this bicycling thing 45 years now. Those things
become second nature and I don't even think about them.
AMuzi
> On Fri, 17 Sep 2010 03:53:19 +0000, Jobst Brandt wrote:
>
>> First item: Do they have the perforations on the cellophane?
>>
>
> There's some kind of treatment to make the cellophane slit in a straight
> line. I've never seen individual perforations with the naked eye and have
> never bothered to look at the cellophane under magnification. I'd assume
> scoring the cellophane, rather than perforating it, would provide the
> same functionality.
>
> The slit's orientation is important because I want to pull the cellophane
> apart lengthwise not crosswise on the patched tube. I'll hold the patch
> to the light and can usually see a faint line at an angle to give me a
> clue as to the slit's orientation.
>
>>> apart, when folding the patch.
>> It should not break when folding the patch. It is intended to be split
>> by stretching the installed patch and patched tube. It will curl
>> outward and can be pulled off to either side at the same time putting no
>> net pull on the patch.
>>
>
> If the direction of the fold is such that the cellophane is on the
> outside and if the fold is along the line of the perforation, then the
> act of folding will stretch the cellophane and pull it apart. Simple
> stretching is not an option because the foil is still attached.
>
> As mentioned above, the slit's orientation on the tube is important. I
> stop with a little slit with the ends of the cellophane still intact. I
> can peel the patch off the foil by pulling a corner of the cellophane and
> I'm certain of the slit's orientation.
>
> Let's also differentiate between creating a slit on the cellophane across
> the middle of the patch and removing the two pieces of cellophane. The
> folding, whether on the foil or on the tube is to start the slit. Pulling
> apart is still necessary to complete the slit.
>
>>> perforation before removing the foil. If the perforation is faulty,
>>> I'll use scissors to cut a snip from either side of the cellophane.
>>> After the patch is applied, I'll stretch the patch while holding the
>>> cellophane on either side snip. The cellophane will split in two. I
>>> can then remove the cellophane from the center of the patch to the
>>> outside edge. The center to outside removal, prevents the patch from
>>> pulling off the tube.
>> I've tried that with meager success, but it can be done, and must be
>> done with all new REMA patches.
>>
>
> scissors. Pulling the cellophane apart is slightly different. Whereas a
> normally one would pull from the center of the patch to the outer edge,
> one starts with an outer edge and pulls to the center and does the same
> thing with the slit on the other edge of the cellophane.
>
> I used to use the scissors after the patch was on the tube and the
> cellophane would not pull apart. I once missed and cut a nice slit in a
> perfectly patched tube. That's why I now start the slit or cut two slits
> with the scissors with the foil still on.
>
> Did the instructions note the difference? Is it possible that you just
> got a bad batch of patches?
>
> were wondering what to do with them. I can conceive that one of their
> sales execs popped up and said something to the effect that he had an
> encounter at an Interbike show a few years earlier and knew exactly where
> the bad batch of patches should be dumped. :=)
>
> Stephen Bauman
In the days when we patched with Tech patches, which have no
perforation on the clear cover, the Tech techs said the
clear cover peels away after using a patch stitcher and
gives that white visual indication of where the roller has
pressed the patch. (I still have my stitcher although I
haven't used it in years)
http://www.gemplers.com/product/8C/Corrugated-Stitcher
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
AMuzi
> On Sep 17, 11:24 am, Jobst Brandt <jbra...@sonic.net> wrote:
>> These are people who do not know what the sand paper is supposed to do
>> and why.
>
> The fact of the matter is they do know exactly what the sandpaper is
> supposed to do and that is why they include it and recommend using
> it.
>
> Jobst's entire existence seems to revolve around his belief that "I
> got vision, and the rest of the world wears bifocals."
>
> It is rare for him to describe anything without his standard mantra
> that nobody else knows anything.
> I am reasonably certain we are only going to see it get worse.
> It's quite sad, actually.
>
> DR
Hey! I resemble that remark!
I have a stripe on my lenses but my girlfriend has _two_
stripes on hers.
(there's always someone worse off)
Jobst Brandt
>>>>>>>>> As I looked at the stock of new REMA Tip Top patches at the
>>>>>>>>> bicycle shop today, I was greatly dismayed to see that the
>>>>>>>>> ancients of REMA are gone and that the new generation is
>>>>>>>>> from the same mentality as the representative whom I met at
>>>>>>>>> InterBike two years ago. That man believed in drying the
>>>>>>>>> rubber cement completely and not removing the cellophane,
>>>>>>>>> and what for if the volatiles that make patches cure to
>>>>>>>>> become part of the inner-tube have already evaporated.
>>>>>>>> I'm waiting for you to explain the chemistry of that. The
>>>>>>>> volatiles are there to attack the surface the cement is
>>>>>>>> applied to. The reaction that occurs is that sulphur
>>>>>>>> cross-links the rubber of the tube to the rubber of the
>>>>>>>> cement to the specially prepared face gum of the
>>>>>>>> patch. Hexane or trichloroethylene is not involved in the
>>>>>>>> reaction. That's why you let it evaporate first.
>>>>>>>> You don't need to worry about the rubber in the cement
>>>> No, you said:
> Why would a sane person want to remove a fresh patch, sort of
> defeats the object?
To determine how well adhered it is. But since you are new to this
forum let me repeat ho one can get an impression of how important
un-removable adhesion is.
The test is performed by laying a standard paper business card
lengthwise between inner tube and tire casing on the center of the
tread on the road before inflation. After riding about 100 miles that
business card will have turned into mm sized confetti because the bias
ply casing squirms that much under normal riding load. The tire
casing has 45 degree angled crossing meshed cords. This is the motion
a patch must survive while 100PSI air is trying to separate it from
the tube.
That is why one should see if a patch is still loose enough to be
pulled of easily before believing it is ready to ride.
Jobst Brandt
AMuzi
> Someone wrote:
>
>>>>>>>>> As I looked at the stock of new REMA Tip Top patches at the
>>>>>>>>> bicycle shop today, I was greatly dismayed to see that the
>>>>>>>>> ancients of REMA are gone and that the new generation is from
>>>>>>>>> the same mentality as the representative whom I met at
>>>>>>>>> rubber cement completely and not removing the cellophane, and
>>>>>>>>> what for if the volatiles that make patches cure to become
>>>>>>>>> part of the inner-tube have already evaporated.
>
>>>>>>>> volatiles are there to attack the surface the cement is
>>>>>>>> cross-links the rubber of the tube to the rubber of the cement
>>>>>>>> trichloroethylene is not involved in the reaction. Â That's why
>>>>>>>> you let it evaporate first. Â You don't need to worrry about
>>>>>>>> the rubber in the cement vulcanizing to the tube before the
>>>>>>>> repair is installed, because it requires activation -- which
>>>>>>>> is supplied by the specially prepared face gum of the repair
>>>>>>>> if you care to, and the repair will stick to it just fine.
>
>>>>>>> I suppose you missed the item citing how van der Waals forces
>>>>>>> repeating it is tedious, there being many fine points.
>
>>>>>>>>> The perforated line on the cellophane is gone so you can't
>>>>>>>>> pull it off, the patch comes off with it as it is peeled from
>>>>>>>>> one edge instead of from the center.
>
>>>>>>>>> As I said, this method of patching leaves a temporary patch
>>>>>>>>> that is so poorly bonded that it can easily be pulled off by
>>>>>>>>> hand... or separate from riding deformation aided by
>>>>>>>>> inflation pressure.
>
>>>>>>>> I've patched a few thousand tires and tubes, on everything
>>>>>>>> have never had one single failure of a patch, using the
>>>>>>>> supplier of cemented patches and repair units specifies
>>>>>>>> exception.
>
>>>>>>> To make up for that I have seen a similar number of failed
>>>>>>> patches from people who followed the "let the glue dry"
>>>>>>> procedure and found a way to cleanly remove these failures and
>>>>>>> replace them with patches that could not be removed and did not
>>>>>>> years ago is a perfect example of why one should not follow
>>>>>>> their write-up.
>
>>>>>> Patch failure is frequently associated with poor surface
>>>>>> preparation. You would have to do some investigation before
>>>>>> claiming a particular patch failure had anything to do with
>>>>>> whether the vulcanizing fluid was wet or dry at the time of
>>>>>> patch application.
>
>>>>> I guess you missed the description why the rubber cement must be
>>>>> semi liquid (gelled) when the patch is applied and why the REMA
>>>>> patches had a special cellophane cover that could be pulled off a
>>>>> freshly placed patch.
>
>>>> No, you said:
>
>>>> "... I have seen a similar number of failed patches from people
>>>> who followed the "let the glue dry" procedure and found a way to
>>>> cleanly remove these failures and replace them with patches that
>>>> REMA man at InterBike two years ago is a perfect example of why
>>>> one should not follow their write-up."
>
>>>> My point is simply that patch failure frequently results from poor
>>>> preparation of the tube surface (failing to fully remove mould
>>>> patch failures because they let the glue dry or because of poor
>>>> former.
>
>>> I would contend that if you can remove the patches cleanly, as
>>> Jobst claims to have done, the rubber solution was never properly
>>> that would be failure to remove the mould release.
>
>> That's one that I find interesting. I have been quite successful
>> removing patches cleanly, if not easily, using a solvent such as
>> toluene. I don't recall why I settled on that as a solvent. I
>> think it was because I saw that in some rubber cement.
>
>> It's usually pretty difficult to get the edge started but then
>> becomes easier when working on the interface using a saturated
>> Q-tip. I have tried the suggested heat method with minimal success.
>> Using my method I am not aware of any visible sign of the patch
>> location after removal.
>
> I haven't tried solvent and especially toluene, a solvent not found
> around my house. I just recall that it has warnings of toxicity:
>
> http://emedicine.medscape.com/article/818939-overview
>
> Jobst Brandt
It's the main ingredient of commercial patch buffing solution.
Hell, everything is dangerous to some extent. Toluene is
effective and one uses such a small amount I can't believe
it's any worse than breathing the dust from sanding a lead
filled frame dent. Or riding between buses every morning.
Jobst Brandt
>>>>>>>>> As I looked at the stock of new REMA Tip Top patches at the
>>>>>>>>> bicycle shop today, I was greatly dismayed to see that the
>>>>>>>>> ancients of REMA are gone and that the new generation is
>>>>>>>>> from the same mentality as the representative whom I met at
>>>>>>>>> InterBike two years ago. That man believed in drying the
>>>>>>>>> rubber cement completely and not removing the cellophane,
>>>>>>>>> and what for if the volatiles that make patches cure to
>>>>>>>>> become part of the inner-tube have already evaporated.
>>>>>>>> I'm waiting for you to explain the chemistry of that. The
>>>>>>>> volatiles are there to attack the surface the cement is
>>>>>>>> applied to. The reaction that occurs is that sulphur
>>>>>>>> cross-links the rubber of the tube to the rubber of the
>>>>>>>> cement to the specially prepared face gum of the
>>>>>>>> patch. Hexane or trichloroethylene is not involved in the
>>>>>>>> reaction. That's why you let it evaporate first.
>>>>>>>> You don't need to worry about the rubber in the cement
>>>> No, you said:
> Why would a sane person want to remove a fresh patch, sort of
> defeats the object?
To determine how well adhered it is. But since you are new to this
forum let me repeat ho one can get an impression of how important
un-removable adhesion is.
The test is performed by laying a standard paper business card
lengthwise between inner tube and tire casing on the center of the
tread on the road before inflation. After riding about 100 miles that
business card will have turned into mm sized confetti because the bias
ply casing squirms that much under normal riding load. The tire
casing has 45 degree angled crossing meshed cords. This is the motion
a patch must survive while 100PSI air is trying to separate it from
the tube.
That is why one should see if a patch is still loose enough to be
pulled off easily before believing it is ready to ride.
Jobst Brandt
thirty-six
Experience tells me well enough, until curiosity gets the better of me
fifteen years later at the same time as some itchy fingers. It took a
knife scraped at the edge to lift the patches and the knife in
combination with my fingers to tear them off in bits.
> But since you are new to this
> forum let me repeat ho one can get an impression of how important
> un-removable adhesion is.
>
> The test is performed by laying a standard paper business card
> lengthwise between inner tube and tire casing on the center of the
> tread on the road before inflation. After riding about 100 miles that
> business card will have turned into mm sized confetti because the bias
> ply casing squirms that much under normal riding load. The tire
> casing has 45 degree angled crossing meshed cords. This is the motion
> a patch must survive while 100PSI air is trying to separate it from
> the tube.
Good job they dont sell business cards as puncture patches then isn't
it? I believe they are commonly made of rubber, just like the tubes
they affix to and have similar elastic properties. I dont commonly
find the need to test my patching having DISCOVERED the manufacturers
instruction provided the information required either printed on the
box or on a little instruction sheet inside.
>
> That is why one should see if a patch is still loose enough to be
> pulled of easily before believing it is ready to ride.
I can't see what you can grab hold of without seperating the partch
first by the use of a knife. You are wierd.
raging raven
2000 mile tire boot pic attached, hopefully. +/- 110 psi, vredestein
tricomp tortezza/michelin aircomp ultralights
http://i105.photobucket.com/albums/m222/raging_raven/IMG_8309.jpg
anonymously yours...
DirtRoadie
I believe that the only thing I said about wet vs dry application of
patches was that nobody has suggested success can be achieved with the
combination of (1) wettish application AND (2) immediate use of the
tube. Otherwise it seems universally agreed that "sufficient" cure
time is required, before or after applying a patch. Everyone but
Jobst agrees in the correctness of the manufacturers instructions to
let the adhesive dry before applying a patch. Jobst is adamant that
letting the glue dry before applying a patch is like trying to apply
dried paint. Strangely, Jobst DOES agree with the paint
manufacturers.
DR
DirtRoadie
>
> DirtRoadie <DirtRoa...@aol.com> wrote:
> > On Sep 17, 2:09 pm, Jobst Brandt <jbra...@sonic.net> wrote:
> > > It is you that place yourself in the unknowing position by repeatedly
> > > claiming that my utterances make no sense and are not understandable
> > > even though stated in plain language.
>
> > The facts speak for themselves.
> > As I have pointed out elsewhere, Occam 1, Jobst 0.
>
> Occam, of course, would disavow your application of his name in such a
> misguided way. Have you identified your three experimental errors yet?
>
acknowledged that a dome need not involve a separation of a patch from
tube? And he approves of your making all his arguments for him from
here on out right?
DR
Tim McNamara
<21604e99-f92f-4b41...@j30g2000vbr.googlegroups.com>,
raging raven <jzcl...@gmail.com> wrote:
That looks about right. US currency paper is much tougher than business
card stock but your sample has been pretty torn up. I have used a
dollar bill as a boot several times because (1) I had one with me and
(2) it's tough stuff.
Peter Cole
On the other hand, I typically leave the cellophane on. It does get
shredded eventually, but it takes a good while. I don't know what the
"confetti" test proves, if anything, about patching.
Tim McNamara
<ce32c859-fb7f-403a...@t3g2000vbb.googlegroups.com>,
DirtRoadie <DirtR...@aol.com> wrote:
You'll have to point that out to me, I am afraid I somehow missed that
post. Odd, since I've read all of the posts in this thread that are
available on my news server.
> And he approves of your making all his arguments for him from
> here on out right?
I am making my own arguments; Jobst is fully capable of defending his
own position.
Have you identified the three errors that invalidate your experiment
yet? Or are you vainly hoping that if you stonewall long enough we will
forget about your bad science?
Tim McNamara
Peter Cole <peter...@verizon.net> wrote:
> On 9/18/2010 1:20 AM, Tim McNamara wrote:
> > In article
> > <21604e99-f92f-4b41...@j30g2000vbr.googlegroups.com>,
> > raging raven<jzcl...@gmail.com> wrote:
> >
> >> On Sep 17, 8:12 pm, Jobst Brandt<jbra...@sonic.net> wrote:
<snipped for manageability>
That there are multiple forces on the patch as you ride which try to
separate the patch from the tube. Air pressure is one, flexure is
another and a third is the bias ply stretching as the tire deforms at
the contact patch. Therefore a good bond is important if you don't want
the patch to fail and to have to fix another flat.
AMuzi
Tim McNamara wrote:
-snip-
> I've read all of the posts in this thread
Time we will never get back.
Peter Cole
> In article<i72eag$kpg$2...@news.eternal-september.org>,
There's also the issue of the patch being much less stretchy than the
tube. If you applied a patch to a tube inflated to the tire diameter,
then there would be no shear force from the difference in stretchiness.
When you patch a deflated tube and let it cure, there will be pulling
upon inflation since part of the circumference won't stretch. An uncured
patch may creep when inflated, and if cured that way, when deflated may
pull the tube into a pucker (dome).
None of the patches I examined yesterday exhibited separation (or talc)
at the puncture site (or anywhere else), that's my consistent
experience, despite typically riding on fresh patches. It may be that
this problem only arises for large punctures, or for overly thick
application of cement, or by not allowing the cement to fully dry before
applying the patch. I'd put my money on the last 2, personally.
I've always (per the instructions) allowed the cement to fully dry, as
tested by the flat of my fingernail. I rub the cement in well when
applying (fingertip) to assure a thin layer and surface penetration. I
don't obsess about "burnishing", assuming that inflation pressure will
press the patch as well. I can't recall a patch job ever failing, either
immediately or over time.
My comments about the length of time (miles) it takes the cellophane to
shred is more to indicate how weak the forces are than to challenge the
confetti phenomenon.
Air pressure will try to lift the patch, but it seems that is unlikely
to happen on even a fresh patch that has been properly applied. I'm
willing to accept that some have experienced this mode of failure, but
given that I haven't -- using many brands of patches, on high & low
pressure tires, on & off road, on a variety of punctures, under a range
of climactic conditions, tells me that the technique (patch & ride) can
be essentially 100% successful, and that those that have that kind of
failure are doing something different than I am. I'm just following the
directions. I don't know what they are doing.
Tim McNamara
Peter Cole <peter...@verizon.net> wrote:
Yes, the patch being thicker and a different material results in it
stretching less. I've tried patching partially inflated tubes and flat
tubes; the latter works fine and is easier, although with a bit of air
in the tube after the glue is applied there's a little white spot at the
hole caused by the escaping air, which is an aid in centering the patch
over the hole. Patches stretch surprisingly well and not that much less
than a butyl tube. Inside the tire, or course, the amount of stretching
is constrained by the rim bed and tire casing.
I am not sure if that puckering of a patch on a deflated tube is due to
the butyl tube creeping from under the patch. That's the first thing
that comes to mind, anyway.
<snip>
> My comments about the length of time (miles) it takes the cellophane to
> shred is more to indicate how weak the forces are than to challenge the
> confetti phenomenon.
The cellophane obviously responds differently to the forces involved,
perhaps in part because it is adhered to the patch, whereas the card is
thicker, is only held in place by pressure and probably has less
structural integrity.
> Air pressure will try to lift the patch, but it seems that is unlikely
> to happen on even a fresh patch that has been properly applied. I'm
> willing to accept that some have experienced this mode of failure, but
> given that I haven't -- using many brands of patches, on high & low
> pressure tires, on & off road, on a variety of punctures, under a range
> of climactic conditions, tells me that the technique (patch & ride) can
> be essentially 100% successful, and that those that have that kind of
> failure are doing something different than I am. I'm just following the
> directions. I don't know what they are doing.
Without us all getting together around Jobst's kitchen table for a tube
patching party, we'll never really know the techniques each other uses
for patching tubes.
Tim McNamara
AMuzi <a...@yellowjersey.org> wrote:
> -snip-
> Tim McNamara wrote:
> -snip-
> > I've read all of the posts in this thread
> -snip-
>
>
> Time we will never get back.
Indeed...
Michael Press
<1740500a-d0ff-41f6...@k1g2000prl.googlegroups.com>,
Jay Beattie <jbea...@lindsayhart.com> wrote:
> On Sep 17, 2:13 pm, DirtRoadie <DirtRoa...@aol.com> wrote:
> > On Sep 17, 2:35 pm, Tom Sherman °_°
> >
> > > > The facts speak for themselves.
> > > > As I have pointed out elsewhere, Occam 1, Jobst 0.
> >
> > > Opinion stated as fact. <yawn>
> >
> > So sorry you are having trouble staying awake.
> > But when you are done with your nap, care to actually address the
> > issue and demonstration I have proposed?
>
> It would be easy to do a controlled experiment. I am down to two
> unpatched tubes after a 30 tube patch-a-thon. They were the ones with
> the really tiny holes that I have to dunk to find. Once I do, I will
> patch one with a wet patch and one with a dry patch and then try to
> peel the patch. The only problem is that I am using cheap-o
> Performance patches and not Rema -- but they both work by the same
> principle. Are there any special rules I should be following with the
> wet patch -- like how wet. Really wet or just kind of wet? How long
> do I wait before trying the peel. I figure both should get the same
> drying time, just to be fair. I know that the wet one would peel right
> off because the glue is still wet.
24 hours.
--
Michael Press
Michael Press
Peter Cole <peter...@verizon.net> wrote:
When a patch is applied to liquid cement on the tube
the patch is free to move toward the tube; and it does
as the solvent evaporates. This is your best bet to get
the patch to adhere to the tube. The patch adheres to
the tube only through intermolecular forces. The closer
you can get it to the tube, the better.
Intramolecular bonds are on the order of 10 ev.
Intermolecular bonds are on the order of 0.004 ev.
--
Michael Press
Peter Cole
>> of climactic conditions, tells me that the technique (patch& ride) can
>> be essentially 100% successful, and that those that have that kind of
>> failure are doing something different than I am. I'm just following the
>> directions. I don't know what they are doing.
>
> When a patch is applied to liquid cement on the tube
> the patch is free to move toward the tube; and it does
> as the solvent evaporates. This is your best bet to get
> the patch to adhere to the tube. The patch adheres to
> the tube only through intermolecular forces. The closer
> you can get it to the tube, the better.
>
> Intramolecular bonds are on the order of 10 ev.
> Intermolecular bonds are on the order of 0.004 ev.
>
I'm willing to believe that a "wet patch" can fully cure if given enough
time. I'm also willing to believe a "dry patch" can, too. I also believe
that a "dry patch" has enough "green strength" to not separate if ridden
immediately. I don't know if that's true for a "wet patch". I expect
not, from reports.
All the instructions I've ever read (save Jobst's) have said to let the
glue dry before applying the patch. That is all I have ever done and
have never had a problem.
All that inter/intra molecular humma-humma seems speculative at best.
Jobst seems to feel that, while the chemistry has remained the same, the
method has changed, but he has offered no proof. I don't recall wet
patching ever being recommended, at least in the decades I've been
patching tubes. I don't think tube patching is a "lost art", I just
think someone is overthinking it.
DirtRoadie
> On 9/18/2010 5:25 PM, Michael Press wrote:
>
>
>
>
>
> > Peter Cole<peter_c...@verizon.net> wrote:
>
> >> On 9/18/2010 11:37 AM, Tim McNamara wrote:
> >>> Peter Cole<peter_c...@verizon.net> wrote:
>
> >>>> On 9/18/2010 1:20 AM, Tim McNamara wrote:
> >>>>> In article
> >>>>> raging raven<jzcla...@gmail.com> wrote:
Well put.
DR
Jobst Brandt
>>>>> The facts speak for themselves.
>>>>> As I have pointed out elsewhere, Occam 1, Jobst 0.
>>>> Opinion stated as fact. <yawn>
>>> So sorry you are having trouble staying awake.
>>> But when you are done with your nap, care to actually address the
>>> issue and demonstration I have proposed?
>> It would be easy to do a controlled experiment. I am down to two
>> un-patched tubes after a 30 tube patch-a-thon. They were the ones
>> with the really tiny holes that I have to dunk to find. Once I do,
>> I will patch one with a wet patch and one with a dry patch and then
>> try to peel the patch. The only problem is that I am using cheap-o
>> Performance patches and not Rema -- but they both work by the same
>> principle. Are there any special rules I should be following with
>> the wet patch -- like how wet. Really wet or just kind of wet?
>> How long do I wait before trying the peel. I figure both should
>> get the same drying time, just to be fair. I know that the wet one
>> would peel right off because the glue is still wet.
> 24 hours.
Only if the tube is not exposed to dry air and the cellophane is left
in place, otherwise, a patch will cure in a few hours, depending on
room temperature. Just like paint, it takes little time.
Jobst Brandt
Jobst Brandt
>>>>>>>> To determine how well adhered it is. But since you are new
>>>>>>>> to this forum let me repeat ho one can get an impression of
>>>>>>>> how important un-removable adhesion is.
>>>>>>>> The test is performed by laying a standard paper business
>>>>>>>> card lengthwise between inner tube and tire casing on the
>>>>>>>> center of the tread on the road before inflation. After
>>>>>>>> riding about 100 miles that business card will have turned
>>>>>>>> into mm sized confetti because the bias ply casing squirms
>>>>>>>> that much under normal riding load. The tire casing has 45
>>>>>>>> degree angled crossing meshed cords. This is the motion a
>>>>>>>> patch must survive while 100PSI air is trying to separate it
>>>>>>>> from the tube.
>>>>>>>> That is why one should see if a patch is still loose enough
>>>>>>>> to be pulled off easily before believing it is ready to ride.
>>>>>>> 2000 mile tire boot pic attached, hopefully. +/- 110 psi,
>>>>>>> Vredestein Tricomp Fortezza/Michelin aircomp ultralights
http://i105.photobucket.com/albums/m222/raging_raven/IMG_8309.jpg
>>>>>>> anonymously yours...
>> Intra molecular bonds are on the order of 10 ev.
>> Intermolecular bonds are on the order of 0.004 ev.
> I'm willing to believe that a "wet patch" can fully cure if given
> enough time. I'm also willing to believe a "dry patch" can, too. I
> also believe that a "dry patch" has enough "green strength" to not
> separate if ridden immediately. I don't know if that's true for a
> "wet patch". I expect not, from reports.
> All the instructions I've ever read (save Jobst's) have said to let
> the glue dry before applying the patch. That is all I have ever
> done and have never had a problem.
> All that inter/intra molecular humma-humma seems speculative at
> best. Jobst seems to feel that, while the chemistry has remained
> the same, the method has changed, but he has offered no proof. I
> don't recall wet patching ever being recommended, at least in the
> decades I've been patching tubes. I don't think tube patching is a
> "lost art", I just think someone is over-thinking it.
I think I have written enough about why patches should be applied to
tubes before the glue dries. It's like so many other substances that
are to adhere to another. Why should the glue be liquid when applied
to the tube and not when the patch is applied to it? I think there is
a lapse of logic there, driven by the advent of pressure sensitive
tapes long ago (Scotch tape). We want everything to stick as easily
as that stuff, but the "Glue-less" patch didn't make the grade, so to
speak.
Jobst Brandt
Tim McNamara
Peter Cole <peter...@verizon.net> wrote:
My understanding of Jobst's description is not that he slaps the patch
onto maximally liquid fresh-out-of-the-tube glue, but onto glue that has
thickened a bit due to evaporation of solvents and it not yet "dry."
Some people seem to be advocating letting the glue completely dry
When I patch tubes, I let the glue dry briefly until it's just tacky
but doesn't smear onto my finger. The reason I have done this is just
that if the glue is too wet, the patch wants to slide around and it's
messy (but give it a try, if you haven't; the behavior of the exposed
red layer and the edges in interesting- it starts to dissolve into the
glue).
Tim McNamara
Peter Cole <peter...@verizon.net> wrote:
> All that inter/intra molecular humma-humma seems speculative at best.
It is a tech group, after all. ;-)
> Jobst seems to feel that, while the chemistry has remained the same,
> the method has changed, but he has offered no proof. I don't recall
> wet patching ever being recommended, at least in the decades I've
> been patching tubes. I don't think tube patching is a "lost art", I
> just think someone is overthinking it.
Jeez, I remember the old repair guys talking about hot patching.
thirty-six
> In article <i73ekc$m7...@news.eternal-september.org>,
> Peter Cole <peter_c...@verizon.net> wrote:
>
> > All the instructions I've ever read (save Jobst's) have said to let
> > the glue dry before applying the patch. That is all I have ever done
> > and have never had a problem.
>
> My understanding of Jobst's description is not that he slaps the patch
> onto maximally liquid fresh-out-of-the-tube glue, but onto glue that has
> thickened a bit due to evaporation of solvents and it not yet "dry."
> Some people seem to be advocating letting the glue completely dry
Yes, with fresh patches.
>
> When I patch tubes, I let the glue dry briefly until it's just tacky
> but doesn't smear onto my finger. The reason I have done this is just
> that if the glue is too wet, the patch wants to slide around and it's
> messy (but give it a try, if you haven't; the behavior of the exposed
> red layer and the edges in interesting- it starts to dissolve into the
> glue).
That is an interesting observation. Knowing that the solvent in the
cement dissolves rubber I should have clicked sooner, but have not
experienced trouble with patching for a long time. The wet(tish)
application is a way to use otherwise poorly adhering old patches.
The reduction in patch performance will occur due to heat, so those
living in hot houses who keep their bike (patch kit) in their living
space will see that patch performance deteriorates quicker than those
living in more acceptable temperatures or who store their kit outside
on the shady side.
New patches work well using the manufacturers described dry
application. Patches of three or four years may show a deterioration
in the UK. I like to get a new patch kit each year and hope not to
use it. If you are further south, then you certainly SHOULD be buying
a new kit every 12 months.
My bike does sit in what was termed a larder, so is kept cool along
with the puncture repair kit.
Poor storage may also give the user an inferior product at point of
sale despite his beliefs about the original product. I'd say look for
repair kits in a sealed tin if you can find them. Otherwise buy a
sealable tin and get your patches from a high turnover internet
agent. I never thought the make mattered much until using skinny HP
tubes and the feather edged TipTops fitted the bill. Other
manufacturers are available and probably as good.
BigP
>
> The cellophane cannot be removed without pulling off the patch as
> well
Yes it can, if the cellophane is snipped first with scissors so that you can
tear it off in two halves.
And I've had fewer (hardly any) failures since I learnt to leave the cement
to dry before applying the patch. I used to get a lot of failures when I
put the patch on while it was still wet. My repairs now are permanent, and
withstand more than 130 psi.
Tim McNamara
"BigP" <p...@pomegranateremovehighlyimpracticalfruitmm.st> wrote:
Are you patching on the road and riding immediately or are you swapping
the tube and patching at home?
When you retire some patched tubes, you might cut through the patch to
see if the patch has separated from the tube as shown in the photos in
the other thread.
Also, examine the edges of your patches. A properly applied patch has
the appearance of having melted into the tube; an improperly applied
patch still has a slightly raised edge (which you can often get a
fingernail underneath and might even be able to pull the patch off). If
the glue is too dry and the solvents have evaporated, the red bonding
layer does not dissolve and bond properly to the tube. It is not the
glue that holds the patch onto the tube like the adhesive on a band-aid;
the glue is there as a carrier of the solvents (if I understand the
chemistry of this correctly).
BigP
> In article <4c96...@news.x-privat.org>,
> "BigP" <p...@pomegranateremovehighlyimpracticalfruitmm.st> wrote:
>
>> Jobst Brandt wrote:
>>>
>>> The cellophane cannot be removed without pulling off the patch as
>>> well
>>
>> Yes it can, if the cellophane is snipped first with scissors so that
>> you can tear it off in two halves.
>>
>> And I've had fewer (hardly any) failures since I learnt to leave the
>> cement to dry before applying the patch. I used to get a lot of
>> failures when I put the patch on while it was still wet. My repairs
>> now are permanent, and withstand more than 130 psi.
>
> Are you patching on the road and riding immediately or are you
> swapping the tube and patching at home?
Mostly at home, but sometimes on the road. On the road, I wait only five
minuites after applying the patch before inflating to full pressure.
> When you retire some patched tubes, you might cut through the patch to
> see if the patch has separated from the tube as shown in the photos in
> the other thread.
>
> Also, examine the edges of your patches. A properly applied patch has
> the appearance of having melted into the tube; an improperly applied
> patch still has a slightly raised edge (which you can often get a
> fingernail underneath and might even be able to pull the patch off).
> If the glue is too dry and the solvents have evaporated, the red
> bonding layer does not dissolve and bond properly to the tube. It is
> not the glue that holds the patch onto the tube like the adhesive on
> a band-aid; the glue is there as a carrier of the solvents (if I
> understand the chemistry of this correctly).
That's debatable, and is being debated in this thread.
The thin edges of my patches are not raised. I have not tried peeling them
off immediately, but when I try some time later, I can only do so after
heating. I don't need them to be stuck any more firmly than they are. Once
fitted in a tyre, they work at high pressure, and stay working for years.
That's all I need.
It helps that the tyre casing effectively presses the patch down.
Nevertheless, I had trouble getting a patch to stick well in the first place
when I used the wet method (as an ignorant youngster), let alone survive the
long run.