Yes you can if its a modified or latex modified thin set. But...You have to get the mixture just right .. Not to wet and not to dry.. Deeper holes it needs to be done in 2 applications so the 1st dosen t sag and run off..If your doing the tile in thin set after it dries your all set. If your doing a mastic you ll need to either skim coat it 1st ( let it dry) or thin coat as you set the so the mastic doesn t dry to fast and skim over. Then tiles won t adhere properly.. GL

I am putting up a new back splash in the kitchen and I was wondering if I could use a thinnest over the drywall to smooth it out better. We already removed the old tiles, scrapped some of the old glue, and patched holes.