There was spots on the pool where there was no gel coat at all and we were looking at bare fiberglass. I was told this was caused by not keeping the proper ph levels. It is an old pool and there was so much chalk on the surface we thought we had a white pool but after sanding it all down realized we indeed had a light blue pool. I just don't want anything like that to happen again and I'm a little nervouse about the epoxy paint holding up for at least a few years. I followed all the directions per the manufacturer and love the results, just want it to last.