Ive never had a silicone based caulk not adhere in the short term but i also never had a tub that moved a measurable distance.View attachment 235385
What am I doing wrong?
Caulking the bathroom tub: The spacing between the tub and the tile is uneven and pretty large in one spot. I've removed old caulk and cleaned the area. Let it sit overnight to make sure everything is dry. Clean again. Put backing rod in. Re-caulked. Let it sit for 24 hours with a tub full of water for a little extra weight while the caulk dries. Let the water out and let it sit for another day before actually using it... And it still seems to be coming apart again. WTF?
I would retry with the best silicone you can find, make sure the backer rod isnt too big. If the gap is bigger than 1/2”, maybe fill with grout first?