# Working glass



## dennis (Mar 1, 2004)

Just a couple of questions. I reciently was given a lot of glass labware. Pyrex beakers, petri dishes, vials test tubes and certuerfuge tubes, glass pipets, ect. and was wondering if I could turn them into useful, or even more useful, items. I have been working on an in tank CO2 reactor to go with a hob filter and need to bend and fuse some of the pieces together. I was able to bend the pipets on my kitchen stove although not very atractively. I can cut glass and have friends with the ability to grind glass. So my questions.

What temps are needed to work the thicker pyrex tubes and how could I fuse pieces together? Just heat? How much. I have seen small propane torches at the hardware store and have used them many tiume for plumbing repairs. I have also seen that they make a Oxygen canister and dual valve to go with the propane ones. I assume this makes a hotter flame due to the addition of the the O2. Would this setup be better?

Also, any helpful tips on bending/ fusing glass would be most appreciated

Thanks


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## dennis (Mar 1, 2004)

Well, with some searching I answered my own questions, at least a little. I found two sites that I will link that seemed very informative and helpful. They are:

http://www.mickelsenstudios.com/articles/TUBEWORK.HTM

and

http://www.ecu.edu/chem/glassblowing/gb.htm#applications

FYI, thinner walled tubing, like pipets, can be bent and blown using you gas stove, the thicker stuff won't be touched. You need added oxygen for that.


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## Aaron (Feb 12, 2004)

Dennis,
All you need for Borosilicate glass (Pyrex) is a standard handheld propane torch tip, but swap the propane with mapp gass. Mapp gass produces a hotter flame than propane. You will be able to bend, slump, fuse etc. with no problems. Just remember to WEAR EYE PROTECTION!!! the one problem you may run into later is having you pieces crack due to the lack of annealing. To make a long story short, the glass will be under different amounts of stress due to heating and cooling in an uneven manner. Glassblowers and lampworkers (what you would be doing is considered lampworking) will usually put their finished work in an _annealer which is basically an oven, set to a temperature just below the slumpling point to the glass. The glass is then allowed to cool very slowly allowing its molecular structure to "reset" itself. You probably do not have an annealer, and your oven will not reach the temps required. What you can do is when your piece is done, take your torch and try to evenly heat the entire piece of glass, kinda wave the flame over the whole thing. do this for a couple of minutes, than bury the whole thing in vermiculite. I will say right now that this it the GHETTO method of annealing and I make no claim that it meets the needs of the material but I have seen it work in the past. My glassblowing friend would do this out of necesity to get his projects done while we were in school and he refererred to it as the Jerusalem technique...

As far as sanding, grinding, cutting, silicon carbide (wet dry) sand paper will work. Use lots of water!!! The ideal and expensive way to to do it is to use diamond infused sanding/ grinding/ cutting equipment.

This is something that is not that hard and I believe anyone with a bit of dexterity can get a hold of. Just don't forget your eye protection!_


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## dennis (Mar 1, 2004)

Thanks Aaron. Great tip about he Mapp gas. I will definately try that. The annealing part I knew, at least from reading those sites. I do have access to a ceramic's kiln (occasoinally) as well as her stain glass grinder Thanks again for the info. One last question about hte eye protection. Is it for breaking glass and heat concerns or due to the light from the flame. What kind would I need. Sunglasses, regular safety glasses or welders helmet?


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