Rob Cox August 05, 2016
If your pool is a concrete or plaster surface that has been painted, you'll likely want to re-paint the pool within a few years. As underwater pool paints age, they wear thin, or lose their bond and flake or peel.
But before you just slap any old pool paint on the surface, you have to know what was used before. Epoxy pool paints are compatible only with Epoxy paint. Chlorinated Rubber can also only be painted over itself, but Synthetic Rubber can go over both Chlorinated or Synthetic rubber paints. Acrylic paints can go over top of Rubber or Acrylic paints, but not Epoxy.
It can be confusing, hence the need for a blog post to help those who struggle with the question; 'how do I know what type of pool paint my pool was painted with?'. It's got to be either Acrylic, Epoxy or Rubber; but you can't tell just by looking at 'em.
If you don't have any old pool paint proposals, invoices, or previous paint order receipts, the type of pool paint that was used to paint a pool previously can be determined by exposing the pool paint to 3 different solvents. The solvent that actually dissolves (softens and smudges) the paint tells you which type of paint is currently on the pool; Acrylic, Epoxy or Rubber.
You can do this test to a well coated section of the wall by wiping the solvents on the surface with a cotton ball, or use a razor to extract a 1/2 inch paint chip from the surface, and drop it into a few ounces of each solvent.
There are 3 solvents that are used to test pool paint chips. They aren't sold in a small 3-Pk Kit unfortunately, but most paint stores will have these solvents in stock, and the large home stores, too. Gallons are too expensive, look for the Quart containers.
A solvent is a liquid that can dissolve other substances. It's not a complete or rapid dissolve but only lightly affects the surface. You're looking for a surface chalking on the paint chip, or for softening and smudgy removal on pool wall test areas.
Clean the paint chip of any oils or dirt, and drop it into an ounce or two of the solvent for approximately 30 seconds. Observe the chip for surface action, like a cloudy haze or micro bubbles on the surface. Remove with tweezers and wipe with a cotton ball or paper towel to see if the paint will rub off easily.
If the paint gets soft and smudgy, you have found your pool paint type. If it's not soft or obviously dissolving, you can move onto a different solvent, and so on, until you find the one solvent that definitely dissolves the paint. To be certain, perform the test with another chip, to confirm the results.
Clean the wall area to be tested with TSP, Simple Green, or just soap and water, to remove any grease or oils from the surface. When dry, use a cotton ball or paper towel to apply the solvent directly onto the painted surface in a vertical area of about 6-8 inches long and 1 inch wide. Rub the area with an up and down motion, and after half a dozen passes, if you don't feel the paint becoming soft and sticky, move to an untested area and repeat the test with a different solvent type.
Use enough solvent to saturate the cloth, but not so much that it will drip off. When you think you have found your solvent and thus your paint type, repeat the test in another area, just to confirm the results.
You may be able to get a local paint store employee to test your paint chip, if they aren't too busy, Or, you can mail your paint chip to Ramuc or to Olympic for testing in their labs, and notification back to you of your pool paint type within just a few days. It's Free!
You can just avoid all confusion and just sandblast or grind the old paint off the pool, but that can be a drastic step to take, and if you don't get it all off ... Pools that have previously been painted can also be replastered or finished in a pebble tec surface, after sandblasting.
And have you checked for a paper trail on the previous pool painting job? It may state the type of pool paint or coating that was used.