04-27-2012, 06:55 PM
You have it right, Brian. There are a few modern silicone-based mold materials that can be used a few times for low-melting point metals, like lead and tin, but they degrade very quickly.
Almost all castings are done by the method you describe, from detailed rings to bronze statues. The wax and the investment plasters are disposable, expendable materials, just part of the price of making the final bronze. Very detailed copies can be made in these silicone molds, using vacuum pumps to remove all the air around the original, even tiny surface features are reproduced.
And high pressure or vacuum is used to force all the air out of the investment to make an accurate copy there. This helps reduce finish/polishing work after the metal is cast and cooled, and the sprues are removed.
Almost all castings are done by the method you describe, from detailed rings to bronze statues. The wax and the investment plasters are disposable, expendable materials, just part of the price of making the final bronze. Very detailed copies can be made in these silicone molds, using vacuum pumps to remove all the air around the original, even tiny surface features are reproduced.
And high pressure or vacuum is used to force all the air out of the investment to make an accurate copy there. This helps reduce finish/polishing work after the metal is cast and cooled, and the sprues are removed.
M. Demetrius Abicio
(David Wills)
Saepe veritas est dura.
(David Wills)
Saepe veritas est dura.
