When I first started metal casting experiments I tried plaster, but abandoned it in favor of shell casting because it was less standard in the industry and I had a lot of trouble melting wax out. Since now I have a lot more tools (de-ionizer, vacuum oven, and kiln) I decided to try box casting again using Ultravest (super-fine investment used for jewelry).

The advantage is that it takes all of 30 minutes to pour it and a day to cure, instead of 8 days for shell casting. First experiment was very unsuccessful as the metal filled 10% of the mold, but today I am trying again.