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Calculating amount of glass for a casting by weight of clay?
Posted: Mon Apr 21, 2014 4:51 pm
by Geo
Hello,
Can someone please remind me how to calculate the amount of glass I will need for a casting, based on the weight of a clay model?
Thank you!
Re: Calculating amount of glass for a casting by weight of c
Posted: Mon Apr 21, 2014 5:07 pm
by Yardic Glassworks
Clays can vary a bit, but when using the low fire clay that I use, it is weight of clay X 1.40 equals glass weight. There are others here who use clay much more than I do, so they may have some additional calculations that they use. Tim
Re: Calculating amount of glass for a casting by weight of c
Posted: Thu Apr 24, 2014 5:46 pm
by nbobb
Or, you can form the clay into a shape, like say a cube, calculate its volume in cubic centimeters, than take that volume times 2.5 to get the grams of glass that you will need. (2.5 grams/cubic centimeters being the density/specific gravity of Bullseye glass).
Re: Calculating amount of glass for a casting by weight of c
Posted: Sat Apr 26, 2014 3:58 am
by Stephen Richard
2.5 is the approximate specific graivity of all soda glass. Lead glass and others are different.
Re: Calculating amount of glass for a casting by weight of c
Posted: Sun May 04, 2014 3:48 am
by Soozin
or use the water displacement method.. Once you take the clay out of the mould, pour water in... and then use the displacement method...
Re: Calculating amount of glass for a casting by weight of c
Posted: Sun May 04, 2014 4:22 pm
by Geo
Found my notes from an old project. A pretty soft and moist clay. Weight of clay x 1.3 worked perfectly. Thanks everyone.