Tiling in a Zero-Radius Undermount Sink (How to Seal Properly)
Doing a remodel on my kitchen. Planning to use tile countertops with a zero-radius undermount stainless-steel sink.
I want to be SURE that the edges of the sink not only look good, but are sealed properly. The sink came with clips, and has a 3/4" lip all the way around.
I plan on putting new plywood down, followed by new cement board, followed by tile. The sink mounting hardware works by placing a threaded insert down through the plywood from the top, then using brackets and screws from underneath to pull the sink up to contact the bottom side of the plywood. Visually, that makes the metal edge of the sink begin just below the plywood level.
That will leave me with a visible edge of plywood, cement board, and tile all around the edge of the sink.
QUESTION: what is the best way to seal and tile over this exposed edge? Can I just put mastic directly onto the exposed plywood and cement board edge, place my tile on, then grout it? Do I need to prepare the plywood edge surface with a sealer in any way? Then, what about the seam at the bottom of the side tiles (the edge facing toward the bottom of the basin)? Should this be grouted all the way around, or sealed with silicone?