Yttrium2
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fixing cracked glass / glassblowing
My retort has somehow developed a crack around where the stopper connects. I am wondering if I can heat the area till red with a torch to seal in the
crack or will this stress the glass? I mean does the entire retort need to be heated to prevent stressing the glass? They do have those giant torches
for killing weeds, how well do those work for blowing glass? - I may need to heat the entire vessel to get rid of the crack..
Also, how do you tell if a glass is stressed? Somewhere earlier I was reading of a way to determine if a glass is stressed and will shatter later on
from improper annealing
any advice on this topic greatly appreciated.
[Edited on 6/23/2020 by Yttrium2]
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Chemetix
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The quick answer is is yes with a maybe. There's a bit more to go over than a few posts can cover. PM me and I'll guide you through what you need to
know and what equipment you might need. There are technique variations that you can use depending on the available equipment, so if you tell me what
sort of equipment you might be able to get your hands on then I can suggest which technique is likely to succeed.
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Belowzero
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Quote: Originally posted by Chemetix  | | The quick answer is is yes with a maybe. There's a bit more to go over than a few posts can cover. PM me and I'll guide you through what you need to
know and what equipment you might need. There are technique variations that you can use depending on the available equipment, so if you tell me what
sort of equipment you might be able to get your hands on then I can suggest which technique is likely to succeed. |
I'd be interested too , please consider doing this in the public square 
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wg48temp9
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You may want watch a glass repair video by Codyslab:
https://www.youtube.com/watch?v=86X5f9xprQ4
Its probably more about the problems of repairing a cracked flask so its a how not to do it video for repairing cracked flasks. I have seen a more
successful video from an experienced glass blower but could not find it. I have tried it myself with mostly similar problems to Cody ie the crack
propagating. Ideally for boro glass you will need at least an oxy propane torch.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Ubya
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propane alone won't work probably, to fix a star crack on one of my little flasks i had to use oxy-propane from a small torch, otherwise the glass is
not hot enough to flow.
this process stresses the glass, you can see the stress spots with a polarizing filter and an LCD screen
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feel free to correct my grammar, or any mistakes i make
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Chemetix
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I'll get a video up on how to repair cracks.
In case you missed the first video, glassblowing for complete beginners, have a look. https://www.youtube.com/watch?v=BjX5JwOvKGM
You can use the bunsen and blow tube technique to heal cracks on small pieces. For bigger pieces with thicker walls you'll need a small oxy- fuel
brazing torch. Jewellery torches or plumbers torches will work.
Codys lab failed using a welding torch because of a few techniques he missed. I'll show you why in the video.
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XeonTheMGPony
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I use a map torch for most my glass stuff, propane turbo torch for smaller tube work.
I greatly miss my smith little torch HVAC edition it was perfect for that shit!
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Chemetix
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You can check out the video on how to heal small cracks I've posted on youtube.
https://youtu.be/MiW7vDJofeA
It's quick and dirty, but gets the point across. Hope it helps.
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Belowzero
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Very nice video, thanks for the effort!
Gives me a lot more confidence in repairing my cracked condensor. The illustration of the polarization is really useful and quite obvious once shown
like this, not so much just reading it from paper.
I am pretty sure people on youtube will like your content , you have a very clear way of explaining and a calm over you that makes it comfortable to
watch.
Okay enough with the feathers
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wg48temp9
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Having watched your first video how you get the scratch to propagated a crack round a glass tube by touching the scratch with molten glass. I figured
the same thing happens when you heat the centre of a crack to repair it.
Thanks for the two videos.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Yttrium2
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can anyone explain how strain develops in glass?
Is this the best cheap polariscope that money can buy?
Would a bunsen burner be a good torch as opposed to the ones that screw onto the propane tanks that do not adjust? - My guess is yes, (would it be a
good purchase?)
and in addition to the bunsen burner, I need a bunsen burner control valve regulator?
[Edited on 6/26/2020 by Yttrium2]
[Edited on 6/26/2020 by Yttrium2]
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