Q: Do you foresee any problems with using ceramic tiles to re-surface the interior of a bathtub?

A: If the tub is fiberglass or acrylic, then the answer is “don't try it.” To tile a fiberglass tub, the tub must be fabricated with the intent of ultimately tiling over it. If cast iron, then you'd have to use epoxy to set the tiles and then an epoxy grout. Cast iron expands and contracts in response to heat at a different rate than tile, so you need a strong, resilient adhesive. Also, when tiling you have to have a rigid substrate, with a solid adhesive bond coming in full contact with the substrate and with the back of the tile. The tricky part of tiling a tub would be that tiles are flat while most tubs are contoured or curved. This means you're probably not tiling over a flat substrate, so it might be difficult to achieve a full, strong bond for a novice, and you'll have problems if it's not done correctly. Small tiles (mosaic) will be best for the contours. Another problem would be installing the replacement hardware, such as the drain assembly and overflow, to accommodate the additional thickness of the tile.