jolly wrote:I wrote a post a couple of days ago but I must have forgotten to hit the submit button. You need to get hold of a kiln and try firing some glass. It doesn't behave the way you think it will. If I were you, I would cut some rounds, stack them and fire them for the first experiment. If you use old windows, it won't cost much. Then I would try putting tiny shards of glass on the very edges of each layer and try fusing that. Unless you figure out some kind of flux or other ingredients to add with the molten glass, I would stay below 1500 F. By the way, Pilkington melts their batch at 2900F and pours the glass for windows at 2000F. But they know what they are doing. Go watch a Youtube video about their process, it might help. Watch videos on working with molten glass, you might get some ideas there. No one I've heard of casts molten window glass for reasons. It is fun to play with old windows though so go for it but, really, fuse some window glass in a kiln first to get started. There are some ring molds that people use for pot melts which you can search for. Have fun.
Thank you for posting about the shards. I came back to post my idea of a bar going across the edge of the bottom piece, propping up the edge of the too piece till it slumps over, giving air space to escape.
Your shard idea is simpler, except I don't have shards. I'll use a strip of stainless steel instead, sticking 1mm in.
Shards make sense though for people who want to fuse not melt.
As for the manufacturers, 2900 sounds believable, and likely necessary for the small pieces. I wonder if they use the incoming pieces to absorb some of the heat of the outgoing melt or if it is worth it.