spontaneous combustion!!!
so... I had something really weird happen. I was standing in my shop near my polishing motor and I started to smell something burning. I turned around to see smoke pouring out of my polishing hood. The wheel in the picture was by its self on the spindle and it was on fire!?!?
so this wheel... i used Fabuluster, green rouge, and the picaso blue polish on this wheel at different times. I polished united's S57 sterling, a tin bronze alloy and some 14ky, not all at the same time. I know your not supposed to cross compounds and metals on the same wheel I was just being lazy. The last polish was fabuluster and oxidized tin bronze.
so... I did a deep dive in the various metallurgical journals and found that the Stearic acid, aluminum oxide, chrome oxide, sulphurated potash (liver of sulpher) and the oxides from the tin bronze can and has been known to have pyrophoric properties. (a compound that needs no self-heat to ignite)
I am glad it happened while I was standing there, my shop might be gone if I wasn't.