Lapping Iron Plates

[JosephS]

I was looking into a stress reliever to have at work and I decided to make some surface plates by lapping. I was going to go for a 3 plate method by using iron, or mild steel, plates


What compound should I start with for lapping cast iron? Would valve lapping compound be the right place to start, or would I need a more abrasive compound? I'm hoping to have a rough starting figure on grit. I see everything from 80-1200. Is there a cheap but works compound?

[jwscab]

Check McMaster carr for lapping compounds. The clover stuff is reasonably priced. The choices they offer gives you an idea of the surface finish you might be looking for.