polishing a chip on a pyrex lid?
Glenn G.
annealing it, will it be OK? A chunk of the rim is chipped and sharp. I
thought about grinding it, and can do that, but it would be quicker to fire
polish it...
Thanks,
G^2
--
"Never argue with an idiot. They drag you down to their level then beat you
with experience".
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Glenn Woolum
> annealing it, will it be OK? A chunk of the rim is chipped and sharp. I
> thought about grinding it, and can do that, but it would be quicker to
fire
> polish it...
You're right about it being easier to fire polish than to use grits.
However, the problem I think you'll run into is that your lid will slump
(melt, distort) before the fire-polish is complete. Keep in mind that
fire-polishing requires the glass spend significant time at temps above the
melting point. Obviously, that makes the glass "melt" out of it's current
shape.
I only use fire-polishing on small pieces that are going to be melted as
part of the process, such as bringing pieces of glass jewelry to full fuse.
This causes edges to round off, and scratches, uneveness, chips, etc...
disappear as the surface becomes glassy smooth.
My advice would be to live with the chip.
--
Regards,
Glenn Woolum
"Glenn G." <NoJunkOrS...@lg-studios.com> wrote in message
news:3bb7b...@goliath.newsgroups.com...
Crystal Images
hoping someone else would address this since my info is sketchy but I
asked someone this question once and was told that pyrex cookware isn't
the same as the pyrex we lampwork with, and it would explode. That's
third-hand, but was enough that I didn't try the experiment. Simpler to
buy a new lid, or live with it.
Margaret
Mike Aurelius
some wet&dry sandpaper and swipe the sharp edge. But start looking for a
replacement lid...
Mike
Sundog
a couple chunks, not very tempered behavior. But I break a nice glass bowl I
had and ...POW... zillion bits. Now that sure seems like it was tempered.
Beginning to think there are no rules to this Pyrex Q.
How about glass coffee pots / decanters....the kind that come with coffee
machines? I have been meaning to take a torch to one sometime, figuring I
could move it around and create a better lip..... which I wouldn't have to
do if so-called designers would follow the golden-rule of design = 'form
follows function'. Instead we get pots that drip all over, but have cute
little spouts on them that look nice.... (argh!). Anybody out there torched
a coffee pot yet?
Jacques Bordeleau
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Mike Aurelius" <mi...@auralens.com> wrote in message
news:trjsgd5...@news.supernews.com...
Glenn Woolum
news:3BB9A3EB...@lightlink.com...
> I assumed his question referred to fire polishing in the torch. I was
> hoping someone else would address this since my info is sketchy but I
> asked someone this question once and was told that pyrex cookware isn't
> the same as the pyrex we lampwork with, and it would explode. That's
> third-hand, but was enough that I didn't try the experiment. Simpler to
> buy a new lid, or live with it.
You're right, Margaret, it's far simpler to knock off the sharp edge with
emery cloth or grinding, then look for a new lid.
I was assuming the use of a kiln since an item as large as a pyrex lid would
be near-impossible to heat evenly in a torch. I would imagine that even a
non-tempered piece as large as a pyrex cookware lid would be exceedingly
difficult (impossible?) to heat evenly to melting temperature using a torch.
In a kiln, tempering wouldn't matter much as long as you heat it very slowly
up to the strain point. Beyond the strain point (of pyrex) you could ramp up
faster. After all, this is how one would anneal the glass (remove the
tempering) if that was the desired result. The problem remains that once one
gets beyond the melting point, the glass will begin losing it's shape, in
fact, at the very same rate that fire-polishing successfully takes place. In
short, the more successful the fire polish, the more melted the piece will
become.
I think Bert Weiss once mentioned a risky technique were you could heat the
glass piece just past the strain point, then open the kiln and hit the
specific area of the glass with a torch (spot heating past the melting
point). Although that would theoretically work, I certainly wouldn't try it.
First it would be very difficult to control the rate of melting in such a
situation. In addition, I can just imagine my torch hoses burning through on
a piece of hot firebrick and sending my humble shop to kingdom come...
--
Regards,
Glenn Woolum
Crystal Images
work with. If you were just polishing out a chip on the edge, you
shouldn't have to heat up the whole lid as long as you heated slowly
enough.
Margaret
man...@glassfactorydir.com
From: IN%"helpc...@worldkitchenhelp.com" 2-OCT-2001 08:26:22.25
Subj: Is it safe to use chipped Py... [Incident:worldkitchen 011001-000065]
---------------------------------------------------------------
Is it safe to use chipped Pyrex?...
SUGGESTED SOLUTION
--------------------------------------------------------------- At 10/02/2001
08:24 AM we wrote - Thank you for contacting World Kitchen, Inc. It is never
recommended to use any chipped dinnerware or cookware. Regards, World Kitchen
---------------------------------------------------------------
Hope this helps.
Liz Scott, Manager
Glass Factory Directory of North America
http://www.glassfactorydirectory.com
Glenn G.
is to grind it, or buy a new lid. But the interesting way is turning out to
be to explore the hot fix.
Crystal: I too have heard that the Pyrex is not the same as that used by
laboratory glass workers and us lamp workers (I include myself loosely).
Glenn W.:I think there is enough mass there that I can spot heat the area
enough to take the edges off without getting it so hot that it melts. IF
it can take the shock of going into the torch... But then, will it survive
cooling?
Jacques: I have broken enough of those coffee pots to suspect that they are
NOT tempered. I would guess they are basically the same a beaker (lab
ware). I say go for it... Those things are cheap.
I guess I will just grind this one and be done with it...
Thanks for all the advice.
G^2
--
"Never argue with an idiot. They drag you down to their level then beat you
with experience".
"Sundog" <n...@home.not> wrote in message
news:gVnu7.13791$b66.1...@newsread1.prod.itd.earthlink.net...
Glenn G.
your post, sorry. But to me it looks like you are simply telling me not to
use it.
What I am hoping to explore here, and doing quite well with all the
excellent comments from the gang, are ways to repair the glass.
Thanks for the advice,
G^2
--
"Never argue with an idiot. They drag you down to their level then beat you
with experience".
<man...@glassfactorydir.com> wrote in message
news:39c9dbf.01100...@posting.google.com...
Glenn Woolum
> Glenn W.:I think there is enough mass there that I can spot heat the area
> enough to take the edges off without getting it so hot that it melts. IF
> it can take the shock of going into the torch... But then, will it
survive
> cooling?
Keep us posted on how it turns out. I've never tried heating a piece that
large with a torch. It seems to me that the larger mass would work against
you rather than in your favor. A small glass rod can be heated to melting
while still holding the cool end, but that is because you can warm the glass
evenly while you bring it up to the melting point. On a larger piece, you
are more likely to have adjacent areas of sharp temperature difference which
would cause thermal shock.
As far as cooling goes, if you want the piece to survive you will need to
anneal it in a kiln, using the temperature ranges and soak times for pyrex.
The annealing time will be influenced by the size and thickness of the
piece. Any time you bring a piece of glass to a temperature above the
melting point, you will need to anneal unless it is a very, tiny small and
thin piece. That will hold true whether you heat the whole piece, or just a
portion of the piece.
--
Regards,
Glenn Woolum
Sundog
local thrift store for anywhere from 25 cents to $1. Check it out ..... and
I do have several 25 cent spare coffee pots around to play with. Don't know
why I haven't already done so....
If you do take after your lid with a torch, don't forget your safety goggles
... flying hot glass bits, ya' know.
Jacques
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Glenn G." <NoJunkOrS...@lg-studios.com> wrote in message
news:3bba9...@goliath.newsgroups.com...
Glenn G.
I am getting real curious now... I think I will go after it with the heat,
just to see what happens. If it survives, I will have to wait to re-anneal
it because I have no kilns at this time. I am in the process of trying to
get 'organized' in the shop... (what a joke!)
Thanks for the warning on the exploding hot glass. Been there, done that...
I have even experienced sticking my finger in the fire! It is truly amazing
how fast 4500 deg. can toast your digits... :0
Regards,
G^2
--
"Never argue with an idiot. They drag you down to their level then beat you
with experience".
"Sundog" <n...@home.not> wrote in message
news:2JGu7.1159$K6.1...@newsread2.prod.itd.earthlink.net...
> Glenn.... I find those Pyrex pot lids and coffee pots all the time at the
> local thrift store for anywhere from 25 cents to $1. Check it out .....
and
> I do have several 25 cent spare coffee pots around to play with. Don't
know
> why I haven't already done so....
> If you do take after your lid with a torch, don't forget your safety
goggles
> ... flying hot glass bits, ya' know.
>
> Jacques
>
>
>