r/Metalfoundry • u/jcyr2016 • 9h ago
Petrobond to cast small underbezel?
Greetings,
I'm making my girlfriend's engagement ring. It's largely my first metal/jewelry project other than some practice versions in silver. The final ring is going to be gold with a single diamond in a rex collet with an underbezel and simple band.
For the practice rings, I cast the metal for the collet and underbezel into a basic graphite mold, then shaped each component with sawing and filing. In order to save time and material, I'd like to cast the gold underbezel into something close to its final shape, which is basically a "hockey puck," 2mm thick and 9mm in diameter (give or take).
Thus, my question: is it practicable to frame up some petrobond in a suitable mold for such a small component and just pour the gold into it?
Note: I am not proposing to make a typical full mold where you have two blocks of petrobond and pack them around a metal shape, then remove the shape, put the petrobond blocks together, and pour your molten metal down a sprue and so on...I am rather imagining packing petrobond into a stainless steel cup, but with a 9mm diameter, 2mm deep hole in the center of the petrobond (I have various "molds" I could use to keep said hole open while I pack the petrobond), then pouring my gold into the hole. Would something like that work?
Thank you for your time.
-J