I have been preparing a flat for re-letting & handover is scheduled for next Monday. In cleaning the bathroom I have noticed that there is a fine crack in the bottom of the bath, approx 30mm long. The crack is in the "ribbed" non-slip area, so a repair isn't going to stand out. I had planned a bathroom re-fit in a couple of years time so don't want the hassle of changing the bath this week. Is it possible to seal the crack with a clear gel coat (bath is a lovely avacado colour), if so, what product should I be buying?