Shoot! It is more than wax that is lost. I think it is me. I sure have been building personal character as I try to find my way. Building character is what happens when you make mistakes and suffer the consequences. I am at least good at that! :)

The bell casting process went south on me. That means it didn't go well. This time it was a blowout as I can see from the result that it isn't good practice to reheat an investment flask if you have to abandon the first heat. I had to try even though I really felt I was already in trouble. It was one of those decision where you know you are going on a mission where the chance of success are slim to none, but you still have to try. Is this picture a bell or a 9/11 memorial?

I am also having serious thoughts of abandoning the vacuum assist type of lost wax casting. I have never had a bad cast using the centripetal casting. I haven't done many but they were all good casts. I am becoming convinced it is the best process for small casting projects.

The vacuum assist certainly works as I have produced some good casts but not consistently. I am doing one of a kind hand made models, so spoiling a cast is a lot of hard work gone. I can't go to the wax injector and squirt out a new master. Currently it is not my intention to become a mass producer. Note I did not write "to ever".

Other than the blow out I just had, the biggest problems with small castings is getting the air out of the way and getting the mold charged with metal before the metal cools to the solidus stage. Even with a hot mold (I cast at 800 to 900 degree mold temperature) that happens very quickly on thin sections.

With vacuum assist the investment plaster is supposed to be porous enough that the air can be sucked through the investment with the vacuum. The metal being too dense to follow. That seems like hocus-pocus magic but it does seem to be true.

It is still a race against time between getting air out and the metal cooling. I have written it before. The difference is a pour that takes one second using gravity and a slight suction or slamming the metal into the mold under high G-force that only takes microseconds.

Both will work. Slamming to me seems to be the better choice for small parts. Vacuum assist for parts that are too big or heavy to use centripetal force. Then lastly, a gravity pour for the thick heavy parts that can hold the heat while pouring (as in a metal foundry).

Me? I am happiest with the small stuff.