Hi, I'm making a decorative mirror. It was a Rona project that takes a mirror, and adheres it along with tile and moulding to a peice of 1/4" plywood. THe instructions say to use tile mortar. That does not seem to hold and I really want to use the strongest bond possible so this does not come apart and shatter once hung on the wall. A gentleman at Home Depot this morning suggested Omni Grip and said this would be the best and could be used for the tiles as well as the mirror, and I had already picked up super No More Nails for the moulding. Will this all work, or is there a better adhesive for this project?