Uranium glass casting schedules?
We were given a 1x5x5 in piece of Uranium (yellow) glass & we are trying to get some info about kiln casting with a piece. Origin of the glass not known as it was in someones else shop for years. Any suggestions of melting, annealing schedules of this glass Thanks
* since Uranium glass is no longer in production, most of us will never get in contact with it to use it, and experiment with it, and therefore dont have specific temps to give you. I have som U glass, and havent done anything else with it since I got it! But I was planning on following a schedule similar to the Tekta schedule on the Bullseye glass website. It's hard to say how this glass will behave, is it going to melt fast, or slow, will it devitrify horribly, how long to anneal it....you'll have to take some notes on your observations when you try to cast with it. Start with a smaller piece, and see what happens. There are a few schedules to look at when casting glass, but you'll have to find what works for you. By the way, there's little to no hazzard to working with this stuff warm, however, I was told to take precautions when coldworking it, as the Uranium that colored the glass cullet could still be a hazzard when in powder form (sandblasting, grinding etc.) Wear a respirator, gloves......radiation suit?!... just kidding. But DO wear a respriator.
* by the way, I got my U glass on Ebay from a guy named Youk. He's been selling this cullet for a long time, and I was very happy to get the two chunks I got. Fascinating glass!! I'm sure you could find more on Ebay if you wanted.
* I know this glass will require higher temps than Bullseye. I took one of the slabs like I gave to Dick and ran it up to 1500 and held for 1 hour to see if the slab would flatten out and it did not. I annealed at 1000 for 1 hour and 100dph to 700 then off. It didn't crack and showed very little stress through a polariscope. This glass came from USSR back in the early '80s and I have no idea about MP, AP, or SP. The importer is no longer in business and I recieved no literature with the glass.
* scooter, did you try to fuse/melt the glass another time at a higher temp? Sounds like really stiff stuff! Interesting!
* I was trying to see if it would spead out and make a bigger patty. It fire polished somewhat but didn't spread out at all. If i took it higher or let it soak longer I guess it would have. It's 6.5" sq. X .650" thick(165x16mm) and I wanted to try to get it down to 6mm thick and slump in a square mold. It's really cool glass, under UV light it glows like neon. I could grind it down in the blanchard to 6mm but I'd lose a lot of material. I could try to split it in my bandsaw but 6.5" sq would not make much of a bowl. I will play with it again when I get some play time.
* The oxide used for the coloring of your glass has little or nothing to do with its casting or annealing characteristics. For an unknown glass you will need to establish the softening point of the glass and then lower the temperature by 50 deg. F in order to establish the annealing temperature (pg. 48, Glass Notes, V 4.0). Once you establish the softening point you should be able to establish the casting temperature.
Like any casting the annealing schedule is established from the thickness of the casting. Just because ita€?s uranium does not change how you cast it or how you anneal it. In other words the annealing rate for your uranium glass or any casting glass follows the same curve. Lead based glass tend to be a bit more forgiving though. Devitrification is a product of the constituents of the glass itself. CaO and Mgo tend to encourage devitrification.
* Thanks to everyone for your help. Henry Halem responed last night & we cracked off a small piece this afternoon & heated it up in our glory hole on a punty. We had a very small bit of spruce pine batch to pick it up from our color oven which was about 1000F. We melted a very small piece & pulled some stringers. They cooled quickly & very stiff glass. We set it up in the color box & we ran a softing point to 1325F. We may play with a mould & a small wax model. Thanks for all your suggestion & help. Will let you all know how it works out & if our fingers fall off.
* If you can wait some mont hand a half, I'm going to a symposium in Russia at a place they used to use U glass and can ask there. (It's a 250year old factory!)
* I wonder if I have a chunk of that glass... bright yellow...several years ago, a few of us in a class at Corning took a walk along the river, picking up "glass rocks" from their furnaces. I was told it glows under black light...
* Yes, it glows under black light if it is glass that is colored with Uranium...I am a long time collector of "Vaseline" glass which is yellow-green transparent glass that can be treated in a variety of ways. I recently bought some sheets from a source that has worked with this cullet for a long time. Most of the recent cullet came from Fenton glass manufacturing company. there is a wonderful website that you can access for probably more than you want to know. I am one of the original founders of the VGCI group and am very proud of that accomplishment. I can ask my source for an opinion on the temperatures involved in using this glass because I am wanting to do some small gifts for people in our club before the next convention in Oct. 2007 in San Antonio, TX.
madolyn who is glad to be able to contribute something for a change!
* Uh-oh, In that case, I think my entire dorm room back in college was colored with Uranium!