Tube Patching Question
AGRIBOB
"...the patch starts the vulcanization immediately but the complete
vulcanization is achieved only after the tire runs on the road."
What ramifications does the above statement hold? How long can I wait before
using my now patched tubes, etc?
Thanks, Bob
jobst....@stanfordalumni.org
First: It is not true that the common patches vulcanize. If you want
to try it, just heat a patched tube by pressing the patch against a
fairly hot Teflon coated frying pan. This is the best method of
pulling off an old REMA patch. Vulcanized patches do not come off.
Unless the patch is fairly well cured, rolling on the road only helps
lift the patch... from the inside to outside starting at the hole.
http://draco.acs.uci.edu/rbfaq/FAQ/8b.1.html
Jobst Brandt
jobst....@stanfordalumni.org
Pete Biggs
> First: It is not true that the common patches vulcanize. If you want
> to try it, just heat a patched tube by pressing the patch against a
> fairly hot Teflon coated frying pan. This is the best method of
> pulling off an old REMA patch. Vulcanized patches do not come off.
That's dissappointing. My Velox patches that appeared to be vulcanizded
have failed the frying pan test. Still, they normally stick and stay
stuck very well.
Why is cement sometimes called "vulcanizing rubber solution"?
Thanks
~PB
(Pete Cresswell)
>What ramifications does the above statement hold? How long can I wait before
>using my now patched tubes, etc?
Dunno from "vulcanizing", but my own incompetance is sometimes a factor - either
through misplacement of the patch or not noticing additional punctures.
To guard against that, I patch a tube empty, let it sit overnite, pump it up so
it's swollen a little more than it would be inside the tire, then just hang it
up where I hang my spare tires.
There's always a tube like that hanging there and when I patch a flat at home, I
just take swap one one that's hanging and still has air in it.
On the road, my prejudice is to swap in a spare tube and fix the flat at home.
--
PeteCresswell
Zog The Undeniable
You can ride them straight away. Not much choice if it's your second
flat of the day and you've used your spare tube!
R15757
<<<snip> How long can I wait before
using my now patched tubes, etc? >>
If your tube is properly patched, you can ride it immediately. All that
"curing" crap is crap. Just make sure to sandpaper the hell out of it and that
the glue is totally dry before you put the patch on.
Robert
Werehatrack
Because the people designing the labels and choosing the terminology
do not understand the product. Vulcanizing is, specifically and
solely, a heat-bonding process that melts one of the two substances in
order to bond the two together, like a solder joint in metal. Some
solvent-based cements are supposed to schieve something similar to
this by a solvent weld, but in my experience, it doesn't occur most of
the time. The adhesive that is carried in the cement's solvent is
what ends up doing the bonding, from what I've seen.
I still have a genuine vulcanizing clamp out in the garage somewhere,
but I haven't been able to find vulcanizing patches for about 20 years
now.
Werehatrack
Same here, but I got caught by the flat from hell this past week. I
was on a no-hurry ride, and got a fairly quick-deflating flat. I
swapped in a known-good tube after checking thoroughly for (and
failing to find) the puncture's cause, pumped it up...and it hissed
down immediately. Popped the tire back off, pumped the tube...and it
had punctured in the same place as the one that was removed. I
*closely* inspected the corresponding part of the tire, and found
nothing, the same as the first time, both visually, with a rag, and
with my fingers. So, I patched the first tube, put it in with the
tube flipped around, pumped...and got halfway home before that one was
punctured in the same place again. Repeat process; patch the flatted
tube in the pack, swap it in, get home...and hiss down in the
driveway. Even with a strong light and the big magnifier, I still
can't find the cause of the punctures. I'm just going to scrap that
tire as cursed, and not worry about it.
Werehatrack
<rau...@earthWEEDSlink.net> thus amends himself:
>On Sun, 14 Dec 2003 11:13:01 -0000, "Pete Biggs"
><pbiggmellon{remove_fruit}s2...@onetel.net.uk> wrote:
>
>>jobst....@stanfordalumni.org wrote:
>>> First: It is not true that the common patches vulcanize. If you want
>>> to try it, just heat a patched tube by pressing the patch against a
>>> fairly hot Teflon coated frying pan. This is the best method of
>>> pulling off an old REMA patch. Vulcanized patches do not come off.
>>
>>That's dissappointing. My Velox patches that appeared to be vulcanizded
>>have failed the frying pan test. Still, they normally stick and stay
>>stuck very well.
>>
>>Why is cement sometimes called "vulcanizing rubber solution"?
>
>Because the people designing the labels and choosing the terminology
>do not understand the product.
As pertains to patching a tube or a tire...
>Vulcanizing is, specifically and
>solely, a heat-bonding process that melts one of the two substances in
>order to bond the two together, like a solder joint in metal. Some
>solvent-based cements are supposed to schieve something similar to
>this by a solvent weld, but in my experience, it doesn't occur most of
>the time. The adhesive that is carried in the cement's solvent is
>what ends up doing the bonding, from what I've seen.
(Vulcanizing more generally applies to heating the rubber to melt,
form and cure it.)
--
My email address is antispammed; pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.
Words processed in a facility that contains nuts.
(Pete Cresswell)
> Even with a strong light and the big magnifier, I still
>can't find the cause of the punctures. I'm just going to scrap that
>tire as cursed, and not worry about it.
Call me obsessive, but I glue a little bit of patch on one side of each tube at
the valve stem. When I mount a tube this little bit of color goes on the same
side as the tire maker's logo.
Then, when I yank the tube, if I know where the tube's leaking I can ballpark
the area on the tire casing and take an extra-good look at it.
--
PeteCresswell
Larry Silkaitis
<"Werehatrack" <rau...@earthWEEDSlink.net> wrote in message
<news:b7gptvoro9gjc247d...@4ax.com...
Vulcanizing is NOT melting. It is a chemical reaction. Natural rubber
(from trees) is cured by sulfur and heat. The old patched required lighting
the patch and applying and clamping it to the tube.
Werehatrack
It's in molten form during at least some part of the process if I
recall correctly. The heat level needed produces that effect.
Afterwards, if memory serves, the temp for remelting it is higher.
Since synthetic rubber is a different matter, though, the whole
"vulcanizing" term is really not applicable to modern products. My
recollection is that the old vulcanizing patches were both cured and
fused by the heat, but I know that the last few times I tried to use
one during the '60s, they didn't bond worth a damn. The people at the
parts stores advised switching to cold patches. I think the bottom
line is that the hot patches only worked with the old tubes. As such,
"vulcanizing" is *really* an obsolete concept.
Werehatrack
said:
There's this little stub of a tire crayon that I use for the same
purpose...
(Pete Cresswell)
>There's this little stub of a tire crayon that I use for the same
>purpose...
*Tire* crayon? You mean I don't need to use this smelly old Sharpie laundry
marker to draw a black line around the puncture on a black tube and then try to
see it when I place the patch?
Actually, I did try a couple plumber's crayons I had laying around - but they
didn't work...
--
PeteCresswell
Jonathan Kaplan
type kit) I have it patched slightly inflate it to check it. Then I
re-install the tire. When I get to about 80psi, it lets go. What am I doing
wrong? (I always end up replacing the tube)
Ken
news:hdKdnTqCdez...@comcast.com:
Can't tell what you're doing wrong without knowing exactly what you're doing.
Personally, I haven't had a patch fail in many years.
Josh Gatts
Are you roughing the tube with sandpaper before putting the glue on?
Also, the glue has to be totally dry before the patch is applied. Jobst
Brandt covers the subject exhaustively in the FAQ at:
http://draco.acs.uci.edu/rbfaq/FAQ/8b.1.html
--Josh
Werehatrack
said:
>RE/
>>There's this little stub of a tire crayon that I use for the same
>>purpose...
>
>*Tire* crayon? You mean I don't need to use this smelly old Sharpie laundry
>marker to draw a black line around the puncture on a black tube and then try to
>see it when I place the patch?
Exactly. They exist in yellow and white, they're opaque, they don't
dry out in geologically significant periods of time, and they mark on
tires and tubes very nicely.
>Actually, I did try a couple plumber's crayons I had laying around - but they
>didn't work...
Wrong stuff; too hard, useful for steel and such but not rubber, as
you discovered.
A Muzi
>>There's this little stub of a tire crayon that I use for the same
>>purpose...
(Pete Cresswell) wrote:
> *Tire* crayon? You mean I don't need to use this smelly old Sharpie laundry
> marker to draw a black line around the puncture on a black tube and then try to
> see it when I place the patch?
>
> Actually, I did try a couple plumber's crayons I had laying around - but they
> didn't work...
Tire crayons used for auto, motorcycle and bicycle tire work
are bright yellow and fairly soft - softer than a
carpenter's crayon. We mark the tire, rim and valve on one
side before removing them to repair a flat.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
Mark Janeba
> My
> recollection is that the old vulcanizing patches were both cured and
> fused by the heat, but I know that the last few times I tried to use
> one during the '60s, they didn't bond worth a damn. The people at the
> parts stores advised switching to cold patches. I think the bottom
> line is that the hot patches only worked with the old tubes. As such,
> "vulcanizing" is *really* an obsolete concept.
Probably right about the obsolete. As a historical note, though, I
remember seeing a hot patch applied when I was around 14 and on one of
my first long rides. When the fellow lit that combustible backing, it
made an impressive show in the eyes of the kids standing round.
Fun to watch, but I'm glad we don't need to mess with that stuff. For
the record, many of my spares have 7-10 [cold] patches on them and are
holding well.
Mark Janeba
A Muzi
Cleanliness, usually
The scraper included is not to 'texture' the tube. It is
intended for cleaning. Wrap the tube across the back of
your hand and scuff it so as to remove the dirt and crud.
Better yet, wipe the area with a volatile solvent that can
evaporate without a residue.
Then do not touch the area with your fingers. Spread the
cement in an area slightly larger than the patch as thinly
as will still just be all wet. Allow it to dry ( fifteeen to
thirty seconds). Then make a motion to tear the patch. The
backing will lift and you can remove it, taking care to not
touch the clean surface with your fingers. Press the patch
firmly over the injury for a moment and you're ready to go.
Some patches have a clear top cover. That shows you where a
patch stitcher has been if you use one. (Looks like a dull
1/4 inch wide pizza cutter). If the clear cover removes
easily, remove it. Harms nothing to leave it in place.
See also the FAQ which is thorough.
http://draco.acs.uci.edu/rbfaq/FAQ/index.html
jobst....@stanfordalumni.org
>> First: It is not true that the common patches vulcanize. If you
>> want to try it, just heat a patched tube by pressing the patch
>> against a fairly hot Teflon coated frying pan. This is the best
>> method of pulling off an old REMA patch. Vulcanized patches do not
>> come off.
> That's disappointing. My Velox patches that appeared to be
> vulcanized have failed the frying pan test. Still, they normally
> stick and stay stuck very well.
> Why is cement sometimes called "vulcanizing rubber solution"?
Snake oil! It sounds good and I bet you can't find a definition for
that term. Vulcanizing is done with heat, not fluid.
Jobst Brandt
jobst....@stanfordalumni.org
jobst....@stanfordalumni.org
>> How long must I wait before using my newly patched tubes, etc?
> If your tube is properly patched, you can ride it immediately. All
> that "curing" crap is crap. Just make sure to sandpaper the hell
> out of it and that the glue is totally dry before you put the patch
> on.
You don't have to get pissed off about it. Besides, you are wrong
about that. I think the reasons are adequately explained in the FAQ
that doesn't require you to take it on faith (as you seem to believe)
but gives you means by which you can test the truth of the methods
described.
Werehatrack
I've had very poor results from the self-adhesive patches, but I've
had good results from conventional use-with-glue patches. The square
multipurpose ones seem to be less reliable (for me) than the round
clear-back patches, and the Novara "microdot" patches were just an
exercise in frustration on the one occasion that I tried them. I buy
the smaller round Camel patches almost exclusively now. The larger
ones cover too much area on a tube, and result in excessive stretching
in my opinion.
Pete Biggs
The inflate-to-check bit might be where you are going wrong as the patch
won't be fully cured if test is done soon after patching and there won't
be a casing to effectively help keep the patch pressed against the tube.
Only inflate just enough to round out the tube to make it easier to fit
into the tyre, no more. You'll get almost 100% reliability if patching
technique is good so they'll be no need (and eventually no desire) to
check at all. It /will/ work!
1. Sand tube well - area larger than patch.
2. Apply cement (thin layer will do) - again make sure area is larger
than patch.
3. Immediately inflate slightly to blow bubbles in the cement to mark the
centre point, then deflate.
4. Allow to dry (3 to 5 mins+ depending on conditions).
5. Apply patch (I find ones with feathered edges better), press firmly.
6. Wait at least 5 mins if convenient (pref 12 hours+), do not inflate to
test.
7. Remove celophane/paper (snipping edges in advance makes peeling off
possible without disturbing patch; press down again to make sure though).
8. If edges are not sticking (they should normally stick ok first time),
apply some more cement and wait until it's very tacky before pressing
patch again.
9. Chalk/talk patch if you like.
10. Fit, inflate.
~PB
Robin Hubert
"(Pete Cresswell)" <x@y.z> wrote in message
news:r11ptvo0ekj4admb8...@4ax.com...
Then what do you do when that rare second flat happens? I recommend
replacing the punctured tube with your spare and patching the new puncture
right away so it can cure.
Robin Hubert
Sorni
news:brjr9l$41o7e$1...@ID-144931.news.uni-berlin.de...
> 9. Chalk/talk patch if you like.
Talk to the patch, Gracie?
Bill "please get me home, baby" S.
Dave Kahn
> 7. Remove celophane/paper (snipping edges in advance makes peeling off
> possible without disturbing patch; press down again to make sure though).
Some patches have covers that are very difficult to remove. Folding
the stuck-on patch with the cover on the outside of the curve will
often split the cover making it relatively easy to peel away from the
patch. Peeling from the split towards the edge is also less disruptive
to the feather edges.
--
Dave...
jobst....@stanfordalumni.org
>> 7. Remove cellophane/paper (snipping edges in advance makes peeling
>> off possible without disturbing patch; press down again to make
>> sure though).
> Some patches have covers that are very difficult to remove. Folding
> the stuck-on patch with the cover on the outside of the curve will
> often split the cover making it relatively easy to peel away from
> the patch. Peeling from the split towards the edge is also less
> disruptive to the feather edges.
Rema, the most commonly use patch here and in Europe, has a cellophane
cover with a prepared break line across its center. After positioning
the patch, stretching it in the direction that causes the break line
to separate, the cellophane will peal away from the center of the
patch making it easy to remove without lifting the patch. The break
line is discernible as a faint dotted line on the shiny surface.
Jobst Brandt
jobst....@stanfordalumni.org
Rick Onanian
>RE/
>> Even with a strong light and the big magnifier, I still
>>can't find the cause of the punctures. I'm just going to scrap that
>>tire as cursed, and not worry about it.
>
>Call me obsessive, but I glue a little bit of patch on one side of each tube at
>the valve stem. When I mount a tube this little bit of color goes on the same
>side as the tire maker's logo.
Hmm...this causes me to get this idea: It's not necessary to scrap
the tire. Just cover the problem area with something that the
puncture won't get through -- a couple layers of duct tape ought to
do it. It may be sharp enough, but if it was long enough to make it
through a couple layers of duct tape, then it would be easy to find
with one's finger.
--
Rick Onanian
Rick Onanian
"Liquid Paper" and "Wite-out" correction fluid work great for me. I
also use it for truing wheels.
--
Rick Onanian
R15757
I have read the FAQ on this before and think it should be updated. Your claims
about patch "curing" do not mesh with my experience. In particular you write:
"Assuming the patch was properly installed, it will still possibly leak after a
few miles, if used immediately after patching."
This is because: "...Under the patch, the stretched tube tends to shrink away
from the patch, and because there is no holding force from inflation pressure
at the hole, the tube can peel away from the patch that is held by air
pressure."
Personally I have patched many hundreds of punctures in roadside repairs and
ridden the patched tubes immediately. Number of slow leaks caused by the
mechanism described above: zero.
Perhaps what you mean by this mysterious term "curing" is really just letting
the cement dry completely. In another post, A. Muzi mentions letting the glue
dry fifteen seconds or so. This I think is way too short. I always let the glue
dry for a few minutes, until it has lost all tackiness to the touch, before
applying the patch. Maybe that is why my patches always stick. Also, I leave
the clear celophane on the patch, which might prevent the new patch from
sticking to the tire. There are 20 or 30 such patches on the rear tube of my
everyday bike right now, none of them leaking the slightest bit.
The biggest troubles with roadside patching are extreme cold, in which the glue
just rolls up and goes away, and wind and traffic noise, which makes it very
difficult to locate the puncture.
cheers!
Robert
Dave Kahn
> ...the cellophane will peal away from the center of the patch...
That rings a bell.
--
Dave...
AndyMorris
>>> There's this little stub of a tire crayon that I use for the same
>>> purpose...
>>
>> *Tire* crayon? You mean I don't need to use this smelly old
>> Sharpie laundry marker to draw a black line around the puncture on a
>> black tube and then try to see it when I place the patch?
>
> Exactly. They exist in yellow and white, they're opaque, they don't
> dry out in geologically significant periods of time, and they mark on
> tires and tubes very nicely.
>
Where can you buy them from?
--
Andy Morris
AndyAtJinkasDotFreeserve.Co.UK
Love this:
Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/
Carl Fogel
> Werehatrack wrote:
> >>> There's this little stub of a tire crayon that I use for the same
> >>> purpose...
> >>
> >> *Tire* crayon? You mean I don't need to use this smelly old
> >> Sharpie laundry marker to draw a black line around the puncture on a
> >> black tube and then try to see it when I place the patch?
> >
> > Exactly. They exist in yellow and white, they're opaque, they don't
> > dry out in geologically significant periods of time, and they mark on
> > tires and tubes very nicely.
> >
>
> Where can you buy them from?
>
> --
> Andy Morris
Dear Andy,
Try Checker Auto and similar places. They're
sometimes listed as "tire marker wht," not
"white tire crayon," just to keep us guessing.
It hardly matters, since the search option
doesn't find them anyway.
Sorry about the price.
Carl Fogel