To make your cast iron block, heads, etc. look like they are fresh from the foundry we use our Peterson BK17 oven. The process is to cook your block at about 750 degrees, then move them into our Peterson Shot Blaster to do the final cleaning.
Our blast booth is big enough to put a 3+3 pickup in. Our prefered media is glass. It is a great way to prepare for refinishing almost anything!