“What are those streaks, spots, bumps, blotches, stains or funky things on my white plaster pool finish!!!”

Has anyone with white plaster ever asked this question to a neighbor, the plaster company or just wondered this to yourself. Well if it makes you feel better, 100% of the folks that purchase white plaster as their preferred pool finish have one or more of these issues on their pool whether visible or not. In some pools these issues come on slowly and in others more quickly. In many cases these quirks in the plaster are not very noticeable while the pool is full but once the pool is drained for repair or maintenance, they stand out like ketchup on a white shirt. The 3 most common questions Hamlin Pools gets as a builder on these issues are:

  1. What causes these spots
  2. What can be done to stop the streaks
  3. What can be done to remove those bumps

There is a major industry debate on what causes these blemishes and sorry to say, the industry currently has no clear explanation. Research does continue to be done by various groups but when uncertainties exist on any product the general rule is a move away from that product until better answers are found.

So where is the industry now? Ultimately all parties agree on one common element, white plaster is the most economical cement finish that can be placed on a pool but it is also the softest and least problem resistant. Actually, it has virtually no resistance to stains or etching, nor little ability to hide a stain. Both the ability to resist a stain or hide a stain are critical to any product placed in the rough environment of pool water.

To better understand this problem a little history may help. In the early 60’s and 70’s pools were basically maintained by using powder chlorine and muriatic acid hand dosed daily. Calcium staining was common on the white plaster but in those days white plaster was a much more durable product and better able to with stand the harsh environment of pool water. As the industry advanced, tablet chlorination thru automatic feeders was introduced. In order for the tablets to dissolve slowly and provide a lasting residual, a product was introduced called stabilizer or technically known as cyanuric acid (CYA). Filters evolved as well. The original giant sand filters that had to be back washed every day or 2 were replaced with rapid rate sand filters that could go a week between back washing. DE and cartridge filters were introduced and they could go a month or more. The changes in filtration systems and the addition of stabilizer had a far reaching impact on pool operation that no one anticipated. Water clarity improvement was tremendous. A safer water environment could be shown. But the influence of fewer back washes which reduced dilution of minerals and metals along with CYA lock and inaccurate total alkalinity readings had a radical and hidden impact on water chemistry.

The Government also got involved. EPA began to flex its muscles in many areas. For the pool industry, the cement market was hit hard and more specifically the white cement market. The EPA rules and fines forced white cement to increase in price and decrease in quality. Free markets doing what they are supposed to do, found solutions by bringing in cement from all over the world. It was either sold directly with the promise that it had been tested and met US standards or it was blended with US product. Regardless, white plaster would never be the same. Through the 70’s and 80’s new issues began to appear. Finger pointing began between plaster companies, service companies and manufactures. The 3 groups formed organizations to research and find answers. Many joined the NPC or National Plaster Council. They hired what was supposed to be an independent testing laboratory thru Cal Poly in California. Test pools were built and the studies began. The final reports coming out a few years later were vague but the general indication was that water chemistry and CYA or stabilizer were major components to the etching issues and calcium still resulted in much of the staining issues. The results did not sit well with the service companies. They hired their own independent testing laboratories. As can be expected, their results differed slightly. They pointed an accusing finger at the methods used to finish a pool. Both testing groups did agree in some areas but the lines were drawn in the sand based on how they interpreted the studies. The divisions looked like this:

  • The service companies said it was poor cement quality and poor application methods
  • The applicators said it was the service companies and their treatment methods
  • The cement manufactures said it was either the applicator or the service company
  • The customer and builder were left without a solution.

The truth lies somewhere in the unknown. What is known is that there is a major migration away from the use of white plaster as a primary finish. A positive out come of this unfortunate event is that in the true spirit of American innovation new products and ideas for alternative finishes have been developed and they are literally ROCK STARS. Quartz, Glass Tile, Glass Pebbles and Rock Pebble finishes have exploded around the world with Pebble currently taking the lead. White plaster is still in the basic design of the mix but it is being removed as the finish. As the development of alternative finishes continues to be refined, our customers should reap the benefits because these finishes are STUNNINGLY BEAUTIFUL. Few can deny this incredible and dynamic change and I, for one, look forward to more changes and progress in the future.

Happy swimming