Mike, might I suggest reducing the pressure you apply while working your stone(s) on the belt(s). Too much pressure will reduce the amount of water between the stone and belt thereby overheating your stone. I have worked Lapis on my diamond belts and have never had the problem you are experiencing. I work mine up to 50,000 on the belts and then onto the flat lap for final polish. All to often stones are worked too hard on belts leading to overheating (which can cause numerous problems) not to mention premature belt life (expensive). Just wanting to help, Ward.

From Ward - October 28, 2009 at 09:27:03

Message: 68475