Sand mold for IN the kiln

[Jan de Jong]

Hello, what is the best and cheapest way to make a sand mold for in the kiln ? Thank you, Jan

[Tony Smith]

This thread from the archives should be helpful.
http://www.warmglass.com/phpBB3/viewtop ... ld#p346214

Tony

[Jan de Jong]

This thread from the archives should be helpful.
http://www.warmglass.com/phpBB3/viewtop ... ld#p346214
Tony

Thank you Tony. But the problem is.....my knowledge of the English language is too poor. Am I wrong if I think the mentioned thread is about HOT glass ? Jan

[Tony Smith]

Some of the thread talks about hot casting. Then Bert talks about his experience kilncasting:

"Many years later, I was taught how to kilncast with sand. That lesson used 20% dry plaster mixed with the sand. I have switched to 25% alumina hydrate, because it lasts longer for me. I reuse my sand mixes over and over. I have experimented with many different sands over the years. Most I have tried work. The big deal is particle sizes. For the strongest mold, you need a range of particle sizes from coarse to fine. This will create the strongest matrix. If you only use finer particles, the weight of the glass will smush it down more, changing the pattern."

I would start with the 20% dry plaster and sand. Olivine sand is used for metal casting, and I've had success casting sheet glass into a dry plaster/olivine mixture. If you don't have access to olivine sand, then I suppose you could experiment with silica sand.

Tony

[Jan de Jong]

@ Tony Smith: Due to illness a late response.....thank you very much for your answer !!! Jan

[FusedLightStudio]

Hi Tony - I am also interested in this technique - does it matter what kind of plaster? No. 1 plaster, or plaster of Paris...?

[Tony Smith]

I've used #1 plaster. I'm not sure how that's different from plaster of Paris.

Tony