Has anyone ever experimented with coldworking tubes? I guess in my mind I'm specifically thinking about sandblasting/frosting tubes, gently of course. Would a (lightly) sandblasted tube hold up to processing, and what would the concerns be with longevity?

Hey there! That's a great question. While I have not sandblasted or frosted neon tubes, I have soldered stained glass to neon tubes before. I wrapped stained glass pieces with copper foil tape, and also put the tape on the parts of the neon where I wanted to attach the stained glass, then used flux and lead solder to attach them. I did this AFTER I processed the neon. More to your question, I would say just experiment and see what happens. If you sandblast the tube before you process it, I suppose it could crack on the pump as the sandblasting might create stress in the tube. I imagine my soldering onto the neon tube I made probably created some stress. This can be checked with a polariscope if you have one. (I don't have one but would love to get one). You could also try the sandblasting after you process the tube. Just make a little sample stick. The worst that would happen is it would crack the tube. You just gotta try it and see! If you do, I love to hear about your results. Here are a couple of pictures of my stained glass to neon tube.

To add onto this old old thread - James showed us a piece recently by Amber Manns who coated a tube in this black substance and then cut or sand blasted into it a message in writing. I don't have a pic but I believe Amber has one on instagram if you're on there, relatively recently! I think you could cut a high quality vinyl and attach that to a relatively stable tube too.

This one was done at the Neon Symposium held at Pilchuck in 2023.

https://cloud.weblink.ooo/index.php/s/mrqP5a2ET7tiq9H

Not sure if that image upload worked. I guess you can message me and I can send you one. I posted about it in the technical issues. 

Thanks Lila, yeah Amber Mans, currently a student at UW pulled these tubes that they coated in black glass powder (about 3 coats) before shaping and stretching the bubble. Then after pumping the tubes, they used rayzist masking https://www.rayzist.com/ to blast away just the words. 

Amber Mans blasted (and wrote) two truths and a lie into their tubes. The funny thing is all three might have been lies. Amber is an excellent glassblower, pulling very nice tubes consistently despite me doing my best to make their life difficult with my zaney color choices. A video of this can be seen on my peertube, here... 

https://makertube.net/w/bEKBhyzXHvPaaJJ9ZZzvf8

Like Eve said, bombard first, then blast. I have seen tubes sandblasted to give an "aged" look. Softens it up a bit- like the tube has been sitting in a greasy restaurant- for decades.