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Good things are happening in the pool industry.  At the Western Pool & Spa Show in Long Beach last month, several knowledgeable pool plasterers publicly stated that improper plastering practices will lead to various discolorations and poor quality pool plaster.

Ed Rock, owner of San Rock Plastering in Los Angeles County, taught a class on proper and improper pool plastering practices. He stated that if his troweling crew “burns” (overly late hard troweling) the plaster and causes graying, it is not just time for a re-plaster, but also time to retrain his crew.  He also stated that “organic” color pigments, while inexpensive, are extremely problematic (severe mottling, spotting, or blotchiness) and should not be used in swimming pool applications. 

It was pointed out that adding calcium chloride (hardening accelerator) to color pigmented plaster (including in quartz and pebble applications), and adding water to a plaster surface while troweling is detrimental and will lead to white blotchiness or spotting.

In our (onBalance) class on plastering, a plasterer commented that he does not add any calcium chloride to his plaster mixes because of the problems that can be caused. Many plasterers are now using a “non-calcium chloride” accelerator with great results, especially with color pigmented plaster. It was also acknowledged that calcium nodules are due to delaminations and cracking issues.  

Several plasterers (and many service techs) stopped by our booth to mention that they have had great success using the “Bicarb Start-up” program on their newly plastered pools (including Quartz and Pebble). They are amazed on how there is no plaster “dust,” and that dark colored plaster jobs remained dark and uniform. They changed to the Bicarb Start-Up because of problems with the “Acid Wash” and "Acid Bath" program which often results in light colored blotchiness or streaking that develops later.

It was very refreshing to hear plasterers acknowledge that certain plaster discolorations and defects are due to poor plastering workmanship or materials, and not due to unbalanced water chemistry maintenance, start-ups, or high cyanuric acid levels.

An article in the March 2014 issue of Concrete International (ACI) also points out the importance of proper troweling techniques and timing, and not adding water to the finish while troweling in order to avoid color variations (mottling) in cement flatwork applications. 

Plasterers with integrity (like Ed Rock) accept responsibility for plaster defects, and won’t blame innocent service techs and pool owners who maintain the water chemistry. And because of that, they are more motivated to teach and ensure that their finishers follow proper plastering procedures.

Consequently, quality plasterers have few problems (if any) that begin to appear a few weeks after completion, such as gray mottling or white spotting (spot etching). When nothing goes wrong, there is no need to blame someone. The above bodes well for our industry if more leaders from the plastering industry speak out and teach others in an effort to improve plastering standards.