Making torture tubes: Help

Hey guys, I just bought a lot of ten 15mm x 45mm borosilicate glass vials for the purpose of making some torture tubes. I have never done hot work with glass before and was hoping for some pointers. Of course, I will be wearing goggles and long sleeves before I proceed. I know the COE of borosilicate is lower than regular glass but how apt is this glass to shatter? Does borosilicate require a slow cool-down when done? MAPP vs. Propane? Good prodding and shaping tools? Any other pointers would be welcomed. I am hoping to get some nice dimple tubes produced along with some nice twisted tubes. If successful, I may be open to making more and selling them here to interested lumia DIY'ers. Thanks in advance!

i've used a propane torch, pliers, and nails.

usually the grungier it looks, the better the lumia it makes.

Awesome. Thanks, Chris. Looking forward to trying this!

I made a few at selem this year from borosilicate tubing. HankLloydWright got one in the raffle. *retardo

I use an oxy/mapp torch with a #5 micro-torch tip and a high-carbon steel pick for the "torture" step. Use graphite tools if possible. To get nicely-formed dimples, use the smallest, hottest flame you can. A small hot flame is important for localized heating in order to avoid collapsing the tube- especially an issue for larger diameter and thicker-walled glass. Borosilicate is much more forgiving than soda-lime glass in terms of shatter from thermal shock. Boro is usually fine cooling down slowly in air. Depending to the size of the piece, soda-lime will crack easily (and generally be quite fragile) while cooling in air. You don't really need to anneal the borosilicate if you're making torture tubes, but you can always flame-anneal the tubes with a soft flame and a polariscope if you're worried about stresses.

I personally avoid long shirt sleeves for torch work, especially if they're a little bit baggy. However, if you're worried about it, they do make kevlar sleeves specifically for glassblowing. I wear one on my right arm while doing furnace/offhand glassblowing.

Dydidium glasses with welders shade five is recommended for color and fuming. But I think shade 3 would be fine for just clear.

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Originally Posted by CountFunkula

I use an oxy/mapp torch with a #5 micro-torch tip and a high-carbon steel pick for the "torture" step. Use graphite tools if possible. To get nicely-formed dimples, use the smallest, hottest flame you can. A small hot flame is important for localized heating in order to avoid collapsing the tube- especially an issue for larger diameter and thicker-walled glass. Borosilicate is much more forgiving than soda-lime glass in terms of shatter from thermal shock. Boro is usually fine cooling down slowly in air. Depending to the size of the piece, soda-lime will crack easily (and generally be quite fragile) while cooling in air. You don't really need to anneal the borosilicate if you're making torture tubes, but you can always flame-anneal the tubes with a soft flame and a polariscope if you're worried about stresses....

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Bam! You answered every single question I had. Thank you! The vials I am going to use are small diameter and very thin wall so hopefully, I can anneal them easily with a large flame torch after the shaping is done. I figured I could try and get them heated evenly and let them cool evenly. We'll see how it goes! As for tooling, I found some pure tungsten welding electrodes that I will poke and prod with. That should hold up to the heat. Thanks again for all the pointers!

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another way is to get some glass blower bits and heat the whole vial. Roll the vial in the powder when hot and it sticks. You need to cool this slowly over a few hours. I can make some if you want. Not exactly the same thing. Also there is a metal thing with points on it for making wallpaper hanging easier. You can do a whole row with that. Some nails would work to but make sure to heat the nails before they touch the glass or it will cool too fast and crack.

wear eye protection and a thick shirt. glass likes to explode without warning when heated.

Bah, you all worry far too much. Just light the propane torch and get at it :D

I've made a goodly few of these tubes from the small glass bottles and there's nothing special to it. Sure, it may take a couple of goes to get something useful, but you'll soon learn what looks good. Oh, and i've never bothered about the cooling process, just switch off the gas and let 'em cool naturally. Heating them up to quickly and unevenly is more likely to break the glass.

Best of luck ;)

Thanks for all the replies, gentlemen! The glass just arrived today and I am hoping to get at these this weekend. I will post back when I have some results.