Swimming Pool Blog

Fiberglass Pools ~ Care and Conversion

by Myles McMorrow, July 29, 2009

Fiberglass pool care
Like plaster or vinyl pools, fiberglass pool surfaces can be affected by aggressive water conditions. Too much Chlorine or low pH over time can fade the fiberglass gelcoat on your pool. However, fiberglass pool surfaces typically do not erode like plaster, or develop holes like vinyl liners. A fiberglass pool, properly cared for, can last a lifetime. Here's some tips on keeping it clean and bright.
·         The "bathtub" ring which forms on the pool wall or tile caused by body oils, suntan lotions and air borne contaminants can easily be removed with swimming pool tile cleaner or other non abrasive commercial tile or vinyl cleaners. Do not use abrasive cleaners, steel wool, metal scrapers, brushes or tools as these may cause permanent damage to the gel coat finish.
·         Dulled gel coat above the water line may be restored with a heavy cut automotive polishing compound either power or hand applied, followed by a coat of wax. For the high luster look, we recommend Gel-Gloss. The gel-coat finish of your fiberglass pool can be scratched like any other gloss surface. The gel coat is seven to eight times thicker than a normal coat of paint so it is not likely that scratches will be more than superficial. Hair line cracks which may develop over a period of time are not uncommon. They only penetrate the gel coat and do not effect the pool's structure or result in leakage. Scratches and hair-line cracks are repairable with a gel coat repair kit.
·         Most of the dirt and debris that sinks to the bottom of your pool can be brushed toward and into the main drain and will be trapped in the filter. Heavy amounts of dirt and debris should be vacuumed out.
·         Heavy brown staining can be addressed with vitamin C (ascorbic acid) yes it sounds funny but works . You can buy it at most pool stores or in pill form at the health store (big bottle needed) just add the pills to the skimmer basket. It may cloud your pool for 2-3 days while it reacts with the stain.  Once the stains are gone (about 48 hours) you will need to readjust the pH of your stain free pool.


Pool fiberglassing 
Fiberglass gel coating is used a an alternative to pool replastering or converting a vinyl lined in ground pool to a more permanent stronger inground pool. Very popular for years in the south, especially Florida, Fiberglassing is now offered by more pool contractors nationwide.
Fiberglassing a pool will cost about as much as a replaster and most companies offer up to a ten year warranty on the gel coat. The fiberglass is a strong durable finish applied in coatings consisting of 3 parts and many colors are available.  
The fiberglass is applied via a “chop gun”  - a multipurpose spray gun that has 3 ports:  one for catalyst that is the hardener , one for resin , and one for air that feeds fiberglass twine into a Chopper that cuts the strand into 1 inch pieces. The choppers is a wheel that has blades spaced out so the strands get cut evenly  and is powered by the air.  When in use all these components get mixed together in midair coating the pool.

 Fiberglass conversion of inground vinyl liner pools

Fiberglass  is a great self supporting material that does not need reinforcing by other building materials. That is why it can be used for converting a inground liner pool.
Here is how it is done:
  1. Cut and remove the liner and take off all return flanges and skimmer face plates.
  2. The next is the tape work all the coping, returns, drain, and pool deck are taped and covered to prevent overspray (watch out for plants too).
  3. Once the color is chosen, the color pigment is added to the resin part of the mix to create the color.
  4. Now it is time for the first coat using a mix of all 3 components called the “glass coat” (catalyst, resin, and fiberglass strands) after a quick spray of catalyst only  to prep the surface of the pool shell frame.
  5. A mix of all 3 is applied up to 1 inch covering the pool. (usually in 6x6 foot sections at a time).
  6. After the section is sprayed it is rolled using a paint roller to flatten any of the strands that are sticking up , these can harden like nails or spikes if this is not done (ouch, you would not want that on the bottom of a pool) a paint brush is then  used to “tuck “ the fiberglass into grooves that were made under the tile and around the returns.
  7. The first coat is then allowed to dry for 24 hours when dry it will look rough because all the strand is exposed. After the first coat is dry a sanding is done using a coarse sand paper. This is to knock off and smooth any of the spikes and nails that may not have gotten matted down. At this time you cut the overspray at the tile and around the returns and drains. A sharp razor knife works best Try to stay as close to the skimmer and returns/ drains when cutting the overspray.
  8. The last coat is ready to be applied but only 2 parts are used in this coat. The pool is now sprayed using only catalyst and resin for a smooth finish this is called the “Gel Coat” (there is no rolling for this coat) The gel coat is left to dry for 48 hours the skimmer and returns/drains are scored with the knife and all tape is removed.
  9. Next put the skimmer frames and return flanges in place and with a knife you punch through the fiberglass to make room for the screws to mount them (you should always use new gaskets on all returns and skimmers to prevent leaks).
  10. The pool is now ready to fill and enjoy!

For more info on Fiberglass pools, including fiberglass pool installations, please see our FiberGlass Pools Page