Here is another thought. A few years ago I had the bottom of my sled sprayed with "Rhino Lining". Sounds weird but hear me out.
It was an old boat with a few leaks. I had it sprayed without any texture. It came out smooth (no extra drag in the water) and it sealed all the leaks. That stuff is also self sealing. I have run it up on the gravel and beached it on everything from shale to volcanic rock. 4 years old and it still looks like new.

NAPA sells a product very much like it. It is either brushed or rolled on. It sells for about $25/qrt. The problenm I have found with the epoxy based coatings like "Gluvit" is that it almost takes an act of God to remove the old so a new coat can be applied properly. It also has a tendency to crack.

Good luck!....DB