[glassmaker]

Originally Posted by Floorkasp

I know that in the 1900's, lampworking in Venice and France was sometimes not done on a mandrel with bead release, but straight onto copper. The copper would then be dissolved in nitric acid.

The safety precautions to do this would be extensive, but I was wondering if anyone has tried this. I have come up with a bead design, but the beads are pretty impossible to remove from the mandrel. Too many weak spots to withstand the pressure that comes with removing it.

So I thought it might be an option to use this method. (A long shot, I know...)

I tried it many, many years ago when I had access to a laboratory chemical fume hood and as many nasty acids as I needed. Believe me, it isn't worth the trouble. Not to mention that nitric acid is one of those items the feds frown upon "regular people" having access to since 9/11.

I would suggest coming up with a different solution, perhaps a tungsten mandrel that you can remove by heating? If you insist on pursuing the copper/acid, use tubing for a mandrel instead of wire. There will be a much larger surface area for the acid to attack. But I still strongly discourage it.

Brad

P.S. If you still plan on dissolving out the copper, Holly's suggestion of ferric chloride might be better a better plan than using nitric acid. (Although I don't have any experience with it myself.)