Is soda lime glass how workable? I was ordering some tubing for my apparatus and discovered it was SLG instead of borosilicate. Should I be able to
heat and bend and work the tube with normal propane torch?
I have made this numerous times with other glass I have so I have basic skill to do it, but I don't know what glass it is.
I know for a fact that "ordinary glass" that bottles etc. are made, will just simply crack and fall apart the moment you apply heat to them.RedDwarf - 22-5-2020 at 05:01
In my experience Soda Lime glass tubing is much easier to work than borosilicate, I'm pretty sure when I was a kid that I was even using an alchohol
burner to bend tubing.yobbo II - 22-5-2020 at 05:20
If the wall is fairly thin and you anneal the bends after you make them. It melts easier that borosilicate but expands more so will be more likely to
crack when it cools down if not annealed.
Lead glass is more is the most 'workable' glass because it melts lower again and has a broader range of temperature were it remains plastic
(workable).
YobRefinery - 22-5-2020 at 08:31
If I make for example ampoules from soda glass, should they anneal by just letting them cool slowly?Chemetix - 22-5-2020 at 16:37
Soda glass needs a wider heating range than a small sharp flame, making ampoules from soda glass tubing could be done without any oxy-fuel system. But
it will need a little more than a Bunsen. If you have a small butane jet torch it will have the heat needed to melt and seal the glass. However, the
jet torch will not have a the soft heat needed to anneal or at least spread the heat and cool the work slowly. One alternative is to have a Bunsen
flame and the jet torch flame being directed into the upper part of the Bunsen flame.
You can use the concentrated heat and have a soft outer flame that will prevent the problems of soda glass cracking while being worked.
Lead glass, btw, melts at a low temperature but it needs the right flame chemistry, a Bunsen flame will have too much unburnt fuel in the flame and
this reduces the lead oxide to black grey metallic lead. yobbo II - 23-5-2020 at 14:13
Just as you are finished if you adjust the flame so that it is very sooty and coat the glass with soot. This helps to make it cool more slowley.
The lime soda glass is more sensitive to thermal stress if i remember correctly.
If you heat it and cool it too fast it can crack.
I think this is especially true if you mix parts of soda glass and borosilicate glass as they expand differently when heated/cooled and thus it breaks
at the point where the 2 are fused together.
But every type of glass has its good and bad properties depending on what you should use it for.
Glass blowing with a bunsen
Chemetix - 25-5-2020 at 14:51
I've made a you tube vid of how to make an ampoule with soda glass using a Bunsen burner. It's a beginners guide to working glass with no special
equipment or torches.
[Edited on 25-5-2020 by Chemetix]Refinery - 28-5-2020 at 11:37
I have some tubes, probably made from boro according to sales description, but I easily managed to ampoulize a couple when I tested out. Gonna test
out the soda glass when it arrives.Refinery - 9-6-2020 at 10:38
I made tests and soda glass softens easily and is workable. Air cooling does not appear to cause cracking.Ubya - 9-6-2020 at 11:32
I made tests and soda glass softens easily and is workable. Air cooling does not appear to cause cracking.
if you have a polarizing filter, you can make a makeshift glass stress visualizer by placing it over you phone camera, and placing the piece of glass
between the filter and your computer screen (rotate the filter until a white image on your monitor looks black, or very dark), white areas indicate
stress in the glass
