Can someone tell me the best way to break in new 1,200 and 3,000 grit Crystalite laps to prevent scratching of the facers on quartz and harder gemstones? I have a complete new set of laps which work well but when I go to the above mentioned grits they scratch and undo the nice even finish left by the coarser grits.
Though others will no doubt have different opinions, but a common way of breaking in a lap is with a piece of corundum, the man-made stuff. Plenty of water and give the laps a good rub over to knock off the high spots then, following a wash, you should be good to go. Keep the rubbing piece for this job, so you’ll no doubt use it again on other laps.