This is a problem that I had to address a few months ago. My wife, needed to use a shower chair to bathe after a surgical procedure. So, when I put the chair into the shower / tub, it was a little too tight and it poked a hole in the side of the tub. This was not a good thing to happen, and I needed to figure out a way to fix it without it costing me thousands of dollars.
As I looked at the tub I wondered if I should contact someone looking for handyman jobs in dallas, tx or should I just do it myself? I decided to do it myself since I felt it was an easy fix.
What I did was go to my local store and purchased some spray foam that I could fill in the hole with. I then purchased a tub patch kit that I would then plaster over the hole.
Using the spray foam, I filled in the hole and allowed it to harden up. Then using a knife I cut away all of the excess foam to create a barrier. This would be a place I knew the patching material could lay against allowing for a solid fit.
Taking out the patching kit I removed some of the compound and using the hardener I mixed the two together. Then, using the applicator device, basically a popsicle stick, I started to take this compound and cover over the hole with the material.
Finally, I let it sit and harden for a few hours before going back. Once I went back, I took the small piece of sandpaper that came with the kit and polished it smooth. I then turned on the water and the hole was patched perfectly.