I had the same issue on my Forest River Toyhauler. I purchased a whole new tub. I wonder if Eternabond would work as a temp fix though. Replacing the tub was a lot easier than I thought it would be. I did it while living in it full time in an RV Park. I got mine from RV Parts Outlet for just over $200 back in 2007 it is a Duo Form brand and is a heavy fiberglass not the thin plastic like the original. Not sure if any of this helps but I hope it does. The new tub is still going strong with no issues since 2007