[lunamoonshadow]

Originally Posted by pam

No more comments, but ask yourselves these questions and do the research to find the answers if you really want to begin to understand glass.

1. What makes glass rods shocky? Air in the rods--I've got some *lovely* opal yellow that's "frit on a stick", & all of my sage, copper green, and most of my EDP is like this too. Actually, 95% of my "hand-pulled" colors from moretti/effetre have always been this way. Oh, & lets not forget about "honey crunch"--it certainly stands up to the "crunch" in it's name
2. What causes glass to need to be worked at lower temperatures or in the back of the flame? same thing? Or, could also be that you're stuffing ice-cold glass into a really hot flame--thermal shock can do a job on stuff...or, there's always the "touchy" colors, like the opalinos...but they're just so pretty, they're worth the extra effort to keep pretty...or rubino, work that in too close & you'll burn the "pink" right out of it! Of course, on a hothead, you need to work "back of the flame" or you'll get sooty in your transparents...so there is *that* to consider for "back of the flame" reasons too....
3. What makes a glass stiffer even though it has the same coe as another glass? I believe Tink & John said "viscosity", & that's from the chemical makeup of the glass--transparents are generally stiffer than opaques--that's why ivory falls off the mandrel when you're not looking, but clear takes forever to melt in on a hothead (and you get it all sooty if you've got it too close to the torch head....so back away!)
4. What causes a glass not to flow so that it cannot be shaped in the flame? Lack of heat, or lack of viscosity...or, maybe you're trying to melt boro with a hothead....
5. What is "burning" glass really and why does it happen? Too much propane in your flame or you've got your glass too close to your hothead tip...back away from the torch....slower is better!
6. How can the chemical composition of glass be changed by adding heat? I'd have to ask a chemist, but I'm sure they'd have an answer.
7. What causes glass to foam? Beats me--I've never met "foaming" glass & I've melted a couple rods of BE, a batchload of Devardi, lots of Moretti/Effettre/Vetrofond, a small assortment of Gail's Veiled Gaffer Canes, a bunch of Val's frits, & a whole lot of Lauscha and one whole quarter ounce of boro dichro I tried to add to some vetro black. Turns out *that* doesn't work . I *have* managed to boil some glass (mostly opalino....) but that was purely user error....

~luna
Still making ugly beads, but having a blast of a time doing it.