Yes, it will do harm. First, you stand a good chance of breaking the bond between the tile and thinset if you get on it too quick. Secondly, you can have a condition known as latex migration, where the latex in the thinset comes up through the grout to the surface of the joints, appearing either as a chalky or scaly substance that's tough as nails to get rid of. Even for a wet mud job, though, this should've dried by now, unless you have moisture coming up through the slab.

dianlo is somewhat mistaken. While latex drys faster than oil it actually cures slower. I would wait a minimum of 10 days with oil and 30 days with latex for heavy items like cans, plants etc. I f you plan it out m, you can always paint an extra scrap board and see how long it takes for that to be hard and not mark up. Personally I prefer oil paint on good shelving. Especially if you live in a humid area. BM satin Impervo looks and lasts better than any water based paint. ( I'm a retired painter) A good suggestion for shelves is a water based porch and floor paint if you don't like oil. I painted a 2 car garage that had bare plywood shelves built on all 3 sides floor to ceiling with am porch and floor acrylic latex.( It's a garage after all) 2 coats primer, sand between and one finish and it's still looks great 8 years later

I tiled tumbled stones which have a lot of holes and dents. I PRE-sealed the tiles one day after tiling them, because I don't want the holes to be covered by the grout. I plan to grout in another 2 days (3 days after the tiling). Is the sealant going to be dry or cure for 2 days? The instruction on the sealant does not say how long it would dry or how many coats I need. thanks

Have you called benjamin moore? I know the latex takes a good long while to cure. I'm planning on painting my trim etc. with their new water-based alkyd on my next project...