After tile removal, there were divots and mortar raised chunks in the cement slab. I ground down the chunks to be level. There was also black mastic under some spots. 1) Can I skim coat over black mastic? 2) What do I use to patch the divots? Will the skim coat be enough to cover the divots? I have acid stained before in 1999. It held up great with the top coat sealant until our hurricane/flood this year. After being under 7 inches of standing water for about 24 hours, the sealant has started peeling. 3) Please provide any suggestion for removing the sealant - ammonia? I used Behr Epoxy 1 coat clear for the sealer as the acid stain company's sealer was too expensive for me. Now that I've removed the white tile (yuck) I'd like to do the whole house with acid stain. I don't want tile. The removal process was nasty, dusty. Plus some of my neighborhood who had newer installations were complaining for about 1 month about the squish they heard under their tiles. I need to come to some floor decisions.