Last week in our GRC Factory we experimented with metal casting into a sand mold. We made our fresh Copper based alloy with Nickel, Silicone, Bismuth, Zinc, and Aluminum.
This alloy creates a non- leaded yellow brass. Our experimental melting furnace runs on regular kitchen gas and it has a maximum temperature of 1,600 °C / 2,912 °F. Volcanic lava is a liquid usually at temperatures from 700 to 1,200 °C, so this is some courageous work we are doing in service of the TOVP!
This fire is strong enough to melt all of non-ferrous and most of ferrous alloys. This is the process as follows. Melting 7 kilograms of brass in a silicon-carbide crucible takes 15-20 minutes. Then we pour the metal into the pre-made sodium-silicate sand mold cured with carbon dioxide gas. The casting solidifies within a couple of minutes. Then the model is washed by a high pressure water jet, polished, and then fine tuned. The images and video included show this experimental casting process.