Can I Make A Reusable Casting Mold From Steel, For Casting Silver ?
I want to use something that is faster than ” lost wax casting ” and I was wondering if I could machine a reusable 2 piece mold to pour molten silver in . Let it harden, separate the mold and pop out the unfinished product . I know there might be a proplem with the mold warping , but if I use a mold, lets say each half being a inch or so think . Also what type of releasing agent if any would I use prier to each use of the mold . I was told that talcum powder would be a good releasing agent , but that sounds a little odd ? What i had in mind was pouring about 2 ounces of silver at a time into a mold with the out side diameter of 2″x5″x7″ .

try sand molds. Talkum powder is indeed used for a mold release in sand molds and it does work there – cold, to seperate the parts of the sand mold. I doubt if it works on hot metal. Graphite powder can be used as a mold release, and that won’t burn as easily. It is also good to make the surface of your sand mold smoother, less grainy, though I am not sure a green sand mold will withstand it, a resin bonded sand mold will. Mix the graphite powder with some alcohol to paint on.
Also what is fun to try, you can cut a big cuttlefish bone in two pieces. Carve, wire together and pour your silver in. But the layering of the cuttlefish bone will show, which is great if you want that effect, not good for perfectly smooth surfaces.
All those molds will be for one time/few time use only. But they will allow you to get things with undercuts out of your mold (one time use obviously), steel won’t let you do that.
Depending on the shape you try to cast I don’t know if the steel will not cool off the silver to quickly, and that could be bad for fine details. You may experiment with preheating your mold. If you cast into cold steel, I don’t think you will need a mold release, as the metals won’t bond. At least whenever I pour ingots I don’t have any problems getting the metal out, but then the sides have draft and there are no undercuts – those requirements may limit what shapes you can successfully cast into steel.
So depending on your shape I would experiment. Experiment with bronze or brass, then any failures will be much less expensive.
Think the heat index for steel would not let you cast efficiently. That is why plaster is often used… can cool quickly and still keep its shape.