Wondering if anyone has tried to make a direct casting mold for pewter using Formlabs high temp resin?
Pewter is fully molten at around 300 C and that’s a bit above the HDT of the high temp resin. It’s probably close enough to give it a try for regular gravity feed casting but the mold probably won’t last all that long.
I would say it depends on the thickness of the casting and most likely NO.
The pour temp for pewter is >450° F. In my spin caster which cools the metal fairly quickly I still have to watch the mold temperatures so they don’t burn out. Because they are spinning at anywhere from 600-800rpm depending on the objects the mold will cool down during the cycle.
In a static mold that pour temp is higher than the high temp resin can handle and it will melt. Any tiny details will get lost.
Fumes from the burning plastic are also probably not great to breathe.
Your best bet is to either sand cast or make a silicone mold of the part and cast into that. If there are tiny details and where a traditional parted mold can’t be made then look into investment casting. If you choose a silicone mold then make sure it is capable of casting potted metals like pewter, lead and zinc. These are usually platinum cured and contain high amounts of ceramic powder that helps keep them from burning up. Not all silicones will handle high heat.