iv been having a very low survival rate with these things making it through the high fire. lots of them slump or crack but the ones that made it are rad! i also had the mold so i made an aluminum one for fun. the green 3 hole one is my best so far and it allmost floats! iv been trying to make a high fire ceramic hand plane float for 7 months now and allmost have it. it wants to but cant quite pull it off. maybe it will in salt water.