I need to refibreglass a chlorine pool edge. I have cut back the old/broken fibreglass but it seems to have been put on some kind of skim coat which itself was on top of the main concrete structure of the pool. The slim coat, if that’s what it was, was broken and degraded and has mostly come away. But I feel I need to even up the surface so the fibreglass is supported and doesn’t just break under the later weight of the coping stones when they are put back on top. I will need to be able to squeeze/ ‘pour’ the skim cost under the remaining fibreglass edge to support under there too. But on the other side is a drain so obviously I don’t want the skim coat material going into the drain too. Am I on the right track with the idea of a skim coat? Any product suggestions or tool suggestions? I used Watercrete cement patch successfully to patch vertical spots above the drain but the area involved for skim coat is much larger. (When the photos attached were taken I hadn’t started preparing the fibreglass for repair but I know I have to do that!)
thanks in advance

