I've done a few epoxy flake floors all with good results,a great system but all on cured concrete.I have a small job,only 6 mt sq but over old tiles.The tiles are glazed but low gloss and grotty certainly not like porcelain.I have heard there is an etch or bond improver that would work to make the tiles more adhesive to solvent epoxy.I know that hire Co's like Kennards have a rotary tool that can abrade the surface of but cost is high because of the diamond disk.Any ideas ? thanks Ia.