25mmCrackleTube

The folks in the office are talking about selling 8 foot crackle tubes. So this one was made as a sampler. I had never done one in 25mm, but hey it totally works, especially when you bake out the filling in a kiln! I don't think 8 feet would be too heavy... so long as it was handled carefully. Its slow and meditative work making these- as long as the tube doesn't split open and spill its crushed glass guts everywhere :) The first clip shows the tube "bombarding" with the aging transformer. The idea is to use the most amount of air as you can while still maintaining an arc. The air is a poor conductor and has lots of resistance, so it generates heat when you put current through it. Like sandpaper. The aging transformer only has 60ma of current- so its a gentle sander. The white arc there is air along with contaminants the heat is releasing and it gets the tube hot enough on one side to bend the glass a little. By turning it off and opening the vacuum you can suck air out while the hea