How can I use cerium oxide to remove scratch marks from mineral glass wristwatches?
The simple answer is that you can’t. Cerium oxide is the last step in polishing and to remove scratches you have to remove material. Therefore you have to get several other fine but progressively coarser grits and start with the coarsest. In removing the scratched material, you end with the whole surface uniformly covered with fine scratches so it looks hazy. Then you go to a finer grit on a new pad and remove the material needed to reduce those scratches to a finer haze. And repeat. If at any point you can still see the individual scratches, you have to back up and remove more material to get rid of them as the finer grits remove less and less material. And if you give up, then you have to continue the process to polish the area around the scratches. Cerium oxide is the last step. The removal of material is why polishing scratches from eye glasses and windshields almost never works and usually is not attempted – the result contains optical distortions.
