I’ve had that happen a time or two with the AlumaLite epoxy. It doesn’t like to be very deep…gets hot enough to distort the throw away lite plastic cups I mix it in if I leave too much in there for too long! And once it gets warm it sets up even faster, so there’s no easy way to get the bubbles out before it’s done. 

Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".