Yes I had carbide paper , it lasts longer and does a better job, wet sanding. I posted a photo, what I did is take a 2X4 , 6 inches long, on the 1.5" side is drilled a extremely shallow hole, same diameter as the shim, at the center of the 6 inch length ,ground the drill bit similar to a milling cutter, the depth of the hole is about 55% of the thickness of the shim, this saves your finger nails and allows more even pressure, also reduces strain on your fingers.Thanks Onewizard. 7 min give or take a few is no problem. Really glad you didn’t say 45 min to 1 hour! Do you wet sand?