Depending on the amount of structural damage, bringing pool surfaces back to life may mean one of several options, including replastering, painting or changing the surface altogether. This could mean installing a new vinyl liner, going from plaster to vinyl (or vice-versa) or fiberglassing.
Success in any resurfacing procedure depends strongly on the proper preparation of the surface. This may include the traditional three-step procedure of cleaning the surface with a trisodium phosphate solution, acid washing and a final TSP cleaning, but on heavily damaged plaster, more detailed work like grinding or sandblasting may be required.
Foremost in the minds of resurfacers should be taking precautions against a pool’s “popping” out of the ground because of a high water table in the area.
In fact, the danger of popping causes many professionals to refuse jobs where they fear that the risk outweighs the potential profit. It also puts an emphasis on working with the current pool finish — repairing rather than replacing.
Repairing cracks in plaster pools has gotten a little easier in recent years with the introduction of hydraulic and underwater repair cements, which allow you to do small jobs without draining the pool.
Aqua Creations of Ventura, Calif., has developed a process that uses fiberglass to repair cracks in plastered or previously fiberglassed pools and spas. Richard Dietz of Aqua Creations detailed some of his procedures at a seminar at the recently concluded Western Pool & Spa Show in Long Beach.
Tools needed for this type of procedure include a disk sander, a 4-inch diamond blade grinder, a putty knife, paint rollers and rib rollers.
Materials needed include a bond coat, fiberglass cloth (which Dietz calls "roven woven"), resin putty, polyester gel, a catalyst, masking tape, sandpaper and acetone for cleanup.
The procedure is rather straightforward:
Fiberglass surfaces are growing in popularity because — while they cost 20-to-40-percent more than plaster — they offer longer service life and a generally smoother finish. In addition — according to fiberglass finishers — glass reduces chemical usage and offers a better insulating quality (which may translate to reduced heating costs). Its surface also is less likely to provide a toehold for algae.
But just like any surface, fiberglass also offers certain challenges in the field that service technicians need to address through knowledge and trouble-shooting procedures.
• Delamination is a pulling away of the fiberglass material from the surface substrate. This problem has a number of causes and solutions.
Using fiberglass over an untreated painted surface will cause delamination. Resurfacers need to sandblast and grind the surface to remove paint.
Moisture in the surface at the time of glassing will also cause a delamination problem. This problem can be eliminated by thoroughly drying out cracks and other sources causing moisture.
Again, proper preparation of the surface — grinding, vacuuming, cleaning and bond coating — is the best way to avoid problems down the line. Dirt, grit or oily film left on the surface will cause delamination.
Incomplete coverage of the fiberglass material will cause water absorption through the fibers. You can prevent this by completely wetting out the fiberglass during the lamination process.
Non-pH-stable materials and fillers such as calcium carbonate also have been proven to create delamination problems. Avoiding these materials and using gels that are pH stabilized will eliminate this potential problem.
At the tile line and around all fixtures, care should be taken to properly cut to a minimum of 1/2 inch depth with a diamond blade and seal.
Bubbles in the laminate can be avoided by using proper air release agents in the resins and rib rolling.
• Chalking on a fiberglass pool occurs when a flaky or milky look is present when the surface is rubbed.
This can happen when an incorrect percentage of surfacing agent is used during the finishing gel coat. A minimum of 5 percent surfacing agent should be used. This surfacing agent, which gives the glass its waxy finish, should not be used in the lamination coats.
Again, use of non-pH-stabilized materials in the glassing process can be a cause of chalking. Using fillers that cannot break down from chemical exposure will eliminate the problem.
Improper mixing and use of the catalyst will also cause chalking. The materials should be thoroughly mixed with an electric mixer or applied with a sprayer.
Care should also be taken to resurface only under ideal weather conditions. Temperatures below 60 degrees or above 90 degrees (F) should be avoided, and a canopy over the pool should be used when glassing under bright sun. Resurfacers should check the surface for cure with a solvent before refilling the pool. In addition, heaters should be used to warm up resins in cold weather.
• Staining — a brown or gray look to the surface — can be caused by iron fallout due to low alkalinity levels in the water in combination with cast iron headers, impellers or high metal content of your fill water. Use of a sequestering agent will help to keep the metals in suspension. This is especially important during the start-up procedure.
An improper cure can also lead to staining. Maintaining proper alkalinity in the 100-150 parts-per-million range and changing out heaters with bronze headers may be necessary.
Test the surface for a proper cure with acetone before refilling the pool. It may be necessary to raise the wax percentage, regulate the catalyst or heat the resin to promote curing.
• Cobalting is a common problem in fiberglass-surfaced pools. Cobalt is present in all resin materials used in the process and often presents itself as black spotting on the surface.
High levels of chlorine in combination with microscopic holes in the glassing material can cause cobalting. A thorough mixing of the resin with an air-release agent in a high-shear mixer should prevent this problem. Service professionals also should avoid dropping trichlor tabs into a fiberglassed pool without using a floater.
A higher concentration of wax in the finish coat provides a barrier and prevents cobalt from being attacked by the chlorine. The catalyst can also be adjusted depending on weather conditions, and the use of non-corrosive, isothalic resins will help combat cobalting.
• Blistering — small bubbles usually about the size of a dime — can also occur in fiberglass surfaces. This can happen if the gel coat is applied too thin or the surface has not been properly prepared. Solutions to the problem include washing down the laminated surface with acetone prior to spraying on the finish coat and applying a thick finish, using extra caution to avoid runs.
When installers take all the proper precautions and follow correct procedures, resurfacing or repairing with fiberglass can provide years of life to your pools.
Proper care of the surface on the part of you — the service professional — will only add to your customer’s satisfaction.