Oh yeah, compaction. Good thinking Jerry. Compaction is usually acheived by vibrating the bubbles out but if your going to make a thick clay type paste then take small lumps in your hand and press it firmly into the cast. Try to make it so it stays workable while through out this process, if it starts to go off and your still pressing lumps into it ...... actually nevermind about that, we're talking 2" cube.
