Hi Allan, Here in post #26 is the method I use for polishing pinions. I actually built this setup for use in a lathe w/a lever operated crosslide & this is just rigged up with what I had on hand. https://mb.nawcc.org/showthread.php?79402-Making-a-new-cut-pinion/page2 This has the advantage that because the thread on the O.D. of the wood lap rotates the pinion, the polishing retains concentricity of the teeth. There are a few tips about constructing this on the above page, but I can go into more detail if you are interested. It seems to me that using any kind of abrasive to polish brass wheel teeth would charge the brass surface w/abrasive and the wheel would accelerate pinion wear.