I have calked around my new acrylic tub twice (filling tub with water first) and both times, after about a month, the calking separates from the tub. The adheasion seemed good both times and the Silicon sticks to the other surfaces fine. Do I need to prepare the tub surface some how?
Answer:
Your troubles may go a bit(?) beyond that. If the tub is not properly supported at the bottom or against the wall(s), the seal you put in can separate in spite of it having been as completely depressed as possible when you worked on it. I've seen this happen in the past because all it takes is a very little bit of tub rim deflection when someone steps into it.
