How to determining the type of coating on your existing pool. Step 1 - Take a small chip (approximately 1" in diameter) of existing coating and soak in the isopropyl solvent No. 1 for one minute. If the chip dissolves, recoat with Hydrolon. If the chip does not dissolve, go to step 2. Step 2 - Soak another chip in the rubber solvent No. 2 for one minute. If this chip dissolves when rubbing between your fingers, then recoat with Paralon 2 or Optilon. If the chip does not dissolve, go to step 3. Step 3 - Soak another chip in epoxy solvent No. 3 for one minute. If the chip still does not dissolve then recoat with Zeron or Poxolon 2.