I always drilled them myself. I use a #2 bilge crucible and drilled 1 mm holes across the bottom. Probably 30 holes in total. Don't drill the holes too close or you will have a few oversized holes because the clay graphite between the holes collapses. Masonry bits always worked for me.What do you drill the holes with or do you buy the crucible pre drilled?
I think the height of molten gold in the crucible is high that it turns to spaghetti shape. It means the pouring rate of molten gold from top crucible is very higher than the pouring rate of molten gold from holes. Or when the crucible is not hot enough the molten gold solidifies in the holes and then the height of the molten gold will rise up.If the water got too hot some of the shot turned into spaghetti shapes.
If you use graphite crucible, the holes can be drilled with HSS drill bit. You shall not drill continuously, remove bit several times for cooling it, you can also use pressurized air for cooling the bit.What do you drill the holes with or do you buy the crucible pre drilled?
Enter your email address to join: