I want to make a hollow mold and pour pure bismuth. I’ve seen threads on the web dealing with this same deal for bismuth alloys and pewter which have lower melting points, so materials like Nylon can handle the pour. However, bismuth melting point is higher than these - 271.4 °C / 520.52 F.

Are there any materials that can withstand this temperature?

I know there is 3D printing in gold and silver, but looks like the technique is to print in wax then use a plaster mold…

You would generally do a wax print and then mold it in plaster for this. Maybe high temp silicone.

Thanks. By high temperature silicone, do you mean to just print straight in high temperature silicone? The websites that offer these materials do not clearly discuss the temperature resistance post printing - for an application like mine in high temperature metal molds.

You could print directly though the solutions on the market are quite expensive. Getting a wax print and then molding may be more cost effective. At which point casting plaster over wax would be more effective. I generally call alumilite or smooth-on or another manufacturer for silicone questions a few of them have silicones for your application.