first you should have used the 50k diamond on the tin first and only. your machine has variable speed, we run our machines VERY slow and a water drip rate at 25-35 seconds per drip. slow speed and little water using only diamond powder applied by finger tip we create a muddy slur that does the work. too fast and too much water you sling off the polishing agent and water and create instant dry spots that can scratch. as for ceramics the surface is too smooth and the diamond or any polishing agent can’t sink in and do its abrasive action, the diamond just roles like a bearing. as for compounds and oils–no– they are lubs not wetting agents and don’t compress enough to get good action from you diamond. we polish everything on our tin laps, all hardness’s with no problems.