Casting in soap stone

[Jean Fraser]

I am interested in casting pewter in stone molds and am wondering what alloy would work best.There is a 98% tin ,1.5% bismuth,.50% copper. I have experience in silicone molds and this is close to the alloy used but I'm not sure how it would flow in the stone. Would appreciate any advise.

[Frances A Lindblad]

I hope you post your results.
Do you preheat the soap stone as you would an investment mold? I have done some lost wax casting and the heat of the molten silver and the temp of the mold are important to the flow of metal into the mold. Cold stone will "freeze" the metal too quickly or the stone will crack, one would think.
I am also interested in doing some casting but in cuttle bone. I just need to prime a crucible and I am wondering if my torch is big enough.
Best of luck!

[Jean Fraser]

Yes, I would imagine it is nessesary to preheat the mold. This was the case even when casting pewter in the rubber molds. I have done a lot of cuttlefish bone casts and love the patterns that you get on the metal. Much like rings on a tree. Not sure what size torch you have but I use my larger #3 nozzle with my Presto- Lite to prime the mold and cast otherwise it takes forever. Make sure you have good ventilation though ...the burnt bone really stinks!