Many pools are coated with Chlorinated Rubber Pool Paint and after 2 – 3 years it looks like this.
However you may not know if its this type of paint and as its incompatible with epoxies its important to know if your pool has it or not. The easy way to test is to get either some Nail Varnish Remover (Acetone based only) or Epotec Thinners.
Saturate a folded corner of a clean rag, cloth or tissue and then hold against an area of clean paint, above the water line. After 20 seconds remove and check you rag etc. Also place your finger on the paint where the rag was placed. If you have lots of paint, like in the picture, (or on your finger it feels sticky and stringy like melted cheeses on a pizza ) then its Chlorinated Rubber Paint.
The Chlorinated Rubber will need to be removed before applying an epoxy.
This test can also be done if pool still full of water. Just be firm in you actions to put the saturated rag on pool surface, below the water line. Follow same procedure as above. Then remove and it shows the same outcomes.
If not sure, contact us for advice.