This demonstration took place during the Hot Shops 2020 Fall Virtual Open House. Ed Fennell and Frank Daharsh demonstrate how to sand cast molten glass.
1. Glass is made mainly from ordinary sand (made of silica), from soda ash (NaCO3) and from limestone ( CaCO3) 2. Glass can be made from silica alone. However, silica has a very high melting point (1700 degree Celcius), so soda ash is added to lower its melting point. 3. Adding a lot of soda ash makes glass too soluble in H2Ü, so limestone is added to reduce its solubility. 4. 5. 6. It is stated in this book that very cheap glass is green because it contains small impurities of iron. 7. Metallic oxides are added to male different colours. 8. Unlike most solids, glass is not made of crystals and does not have the same rigid structure. It is an amorphous solid. 9. When glass is very hot it flows slowly like a thick liquid.
1. Glass is made mainly from ordinary sand (made of silica), from soda ash (NaCO3) and from limestone ( CaCO3)
2. Glass can be made from silica alone. However, silica has a very high melting point (1700 degree Celcius), so soda ash is added to lower its melting point.
3. Adding a lot of soda ash makes glass too soluble in H2Ü, so limestone is added to reduce its solubility.
4.
5.
6. It is stated in this book that very cheap glass is green because it contains small impurities of iron.
7. Metallic oxides are added to male different colours.
8. Unlike most solids, glass is not made of crystals and does not have the same rigid structure. It is an amorphous solid.
9. When glass is very hot it flows slowly like a thick liquid.
Very informative. I usually do Kiln Fusing. Thanks again.
How do you clean the Final pieces That there is on Sand Stuck on it ?
Why is the glas not cracking during the cooling without a cooling chamber?
Where buy these metal tubs??
May I ask what kind of sand you use for sandcasting?
Hi Oliver! Yes, they use a fine sand mixture that contains bentonite clay. The clay helps give it the detail.
Can you make me a small mold?