Go to any art supply store and buy a small tube of white oil paint. It works about as well as the old standby, white lead. All you need is a slow-drying oil-based pigment to show how the gear teeth are contacting. Before the lace-panty crowd got all exercised about lead-bearing products, it was possible to buy white lead pigment in 1-lb. cans and mix it with just a little linseed oil to get a great indicator dye for gear setup which also made the best possible lubricant for lathe centers. I've still got enough white lead to last me the remainder of my short lifetime, and I'm hoarding it!

Edit: Prussian blue is still used around machine shops as a high-spot indicator for lapped surfaces. Any machine tool supply store should have it in stock. Ditto for the online machinists' suppliers. It's absolutely essential for scrape-fitting 216 Babbit-bearing rods before shimming them for oil clearance!
Jerry



"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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