How do you charge this felt pad with pumice? The videos show lathe wheel use, where you put the pumice-water mix on the glass, but I’m not sure that’s how to do it on a lap grinder. Thanks! Your site has so much good info!

It's very similar in that you'll mix your pumice with water to create a mud consistency and apply it to the center of the felt pad with only a slow drip of water in the center.

You'll want the grinder to move slower than you would for diamond grinding so you don't lose your pumice to centrifugal force. Work the piece in a random pattern across the pad and occasionally pick up the piece and check for pumice. Re-apply to the disk as necessary.

You can watch our Coldworking 101 Video on Pumice to see it in action on a flat lap grinder.