White plaster is not a good finish.

Marble Dust acid test

White plaster is not good. It is too easily damaged by unbalanced pool water.

 

Marble Dust acid reaction

White plaster is not a good investment.

 

Standard white plaster is not a good finish to invest in for your pool replaster.

White plaster used to be the most common type of finish installed. This changed after testing showed the standard plaster was too easily damaged by out of balance water.  Standard plaster is a combination of white marble dust and white Portland cement. The marble dust registers less than a 3.0 on the Mohs Scale of Hardness. It is a very soft material. Portland cement registers around a 2.0 on the same scale. Standard plaster can be colored by adding pigment to achieve a desired color. It must be mentioned that doing this will result in an upgraded standard finish in expense, but you will not receive an upgrade in quality equal to the expense.  Standard plaster is the weakest plaster finish on the market.  It cannot stand up to water chemistry imbalances and generally will last 5 years with proper balanced water chemistry. Far less in unbalanced water chemistry.  How long a finish will last is a relative term. I refer to that as how long it will be enjoyable relative to how rough it has become or how easily it is stained.

Many homeowners and pool service companies will acid wash their white plaster pools in an attempt to remove stains.  This is the worst thing you can do to a standard plaster! When standard pool plaster is acid washed, the acid oxidizes the marble dust and the cement, effectively removing the outer finish coat of the plaster. Leaving behind the rough inner matrix of the finish. Initially stains are removed and the plaster is bright white.  But due to the roughness left behind stains return very quickly.  The finish becomes so rough you will no longer enjoy the pool.

Marble dust aggregate, used in standard plaster, placed in a glass beaker will oxidize completely to a liquid when combined with acid in a very short time, about 30 seconds. The acid is used to simulate aggressive water. When the same test is done with quartz and pebble, there is zero reaction at all.

My Hydro Demo Prep Process has allowed me to see how strong different types of plaster finishes are relative to how they respond to our 40,000 PSI test. I see consistent evidence from insight I have gained over the last 5 years water jetting pools on surfaces of all types, that white plaster should not be used in swimming pools.

If you want your pool plaster finish to last for a long time, do not use standard plaster. Choose a quartz finish or a pebble finish. Make sure it is installed by a National Plasterers Council member. Choosing one of those finishes and allowing someone who is not a NPC member to install it for you, will not provide you the results I expect you to receive, especially if they use a homebrew bond coat.  I will expand on the different quartz finishes options in my post next week.