This story covers the steps and options for painting a swimming pool.
Like any other large structure, swimming pools require periodic maintenance. The best time to perform these chores is in the early part of the year, when the weather is still relatively cool and you can refill the pool immediately after the new paint cures.
Inspect the pool for cracks, chips, and other needed repairs. Repair hairline cracks in a concrete pool with a coat of the proper chlorinated rubber or epoxy swimming pool paint. For slightly larger cracks, use an epoxy patching compound made specifically for concrete pools.
In fiberglass pools, hairline cracks that don't open to the substrate may not need repair; they're a sign of weathering. Repair larger cracks with a fiberglass patch kit. Fix cracks in fiberglass pools immediately; water can quickly damage the substrate and rot it. Buy fiberglass patch kits at swimming pool dealers, auto body supply houses, and watercraft retailers. Follow the instructions that come with the kit.
Hire a pool-care pro to repair cracks wider than 1/8 inch or longer than 1 foot.
From 1 to 3 days, depending on pool size and your skills and experience
Utility knife, paint roller with extension handle, roller pan, sandblaster (optional), respirator, paintbrushes, safety goggles, garden sprayer
Preparing a masonry surface, repairing existing cracks, and applying paint
Drain pool, patch cracks, remove flaking paint, fill holes.
Muriatic acid, pool paints
Drain the pool and remove all debris. Scrape off loose paint (a high-pressure power washer will help). Cut out cracks in the pool shell to a 1/4-inch depth with a diamond saw or grinder. Chip out loose cement. Caulk the cracks, and patch any large chips with hydraulic cement.
Wearing old clothes, boots, eye protection, gloves, and a respirator, and working in sections, apply a coat of 50-50 water-muriatic acid solution mixed according to the manufacturer's instructions. Let the acid soak in for the required time, then scrub the surface with a stiff brush.
Rinse the acid off the walls with a steady flow of clean water from a garden hose, and wash the pool down with TSP solution to neutralize any remaining acid. Apply the paint you have chosen using rollers and brushes and making sure that you have plenty of ventilation.
-- Stop adding chemicals to the water three or four days before draining. Check the pH.
-- Attach a long hose to the drain line so it will drain into your lawn or trees (not the neighbor's). Run the pump until the lawn appears nearly sodden. Turn off the pump and wait several hours. Repeat until the pool is empty.
-- Check with local officials before you allow large amounts of water to run into the storm sewers. It may be illegal.