Creating garden art with empty terracotta pots. I glued three in an afternoon, let them dry and then grouted them 24 hours later.
Here’s how you’re suppose to do it … (directions vary based on how long you want a piece of mosaic tile garden art to last.:) preparation is everything!
Before gluing, clean the terracotta pots out with soap and water. Let them dry overnight. (it’s a good thing)
Seal the inside and outside of the pot with a water-based polyurethane or a couple of coats of Weldbond adhesive. (If you don’t seal it no biggie just don’t water a plant in there.) Let it dry between coats and make sure the piece is completely dry before tiling.
Use mastic adhesive. (there are other good adhesives for tile but mastic works for me.)
Use a sanded grout ( I used charcoal) and mix the grout with a grout additive (instead of water) for more flexibility.
Seal the grout with grout sealer, once it’s dry.
Reseal the outside of the piece with grout sealer, once a year, especially if the piece is exposed to the elements or water.