There is a curing period for all cementitious products. This can be related to a break-in period in which the cement is gaining strength and hardness. The slower it dries the stronger it gets. Pools are felled almost immediately so slow drying is normal. This presents other challenges that include chemical balances and brushing.
It is important to follow the steps below accurately to ensure a proper plaster Start-Up.
- Make sure that there is power to he filtration equipment.
- Fill the pool without interruption to prevent an intermittent fill line.
- Lower the alkalinity to between 70 and 80 ppm.
- Brush the pool daily to remove dust.
- Add enough muratic acid to lower the pH to where it will not exceed 7.6 before the next service call .
- Add 1 quart of a quality, testable sequestering agent per 10,000 gallons. Double if the metals exceed 2 ppm.
- Operate filtration for 48 hours.
- Do not add chlorine or pH increase for 48 hours, as they may bounce the pH, and / or alkalinity. This can cause metal precipitation and possibly stain or discolor the surface.
- At 48 hours, test sequestering, and if necessary, add additional amounts to achieve 12 to 15 ppm according to dosage chart.
- Adjust other water balance parameters to the low end of the Saturation Index.
- Color Plaster well usually need small amount of additional muratic acid to keep the alkalinity down between 70-80 ppm over the first 28 day period. Sequestering agent levels should be checked and maintained at 15 to 220 ppm during this time. This should keep hydroxide formations soft and brushable. Brush exposed aggregates daily with a combination stainless steel and nylon brush during this period, concentrating on paste areas. Do not adjust calcium hardness levels above 175 ppm for the first 28 days. The calcium will usually increase as a result of the growth of calcium hydroxide, which is the factor that raises the pH and alkalinity. If calcium is raised to far in advance, calcium can exceed manufacturers recommended maintenance levels. Exposed aggregates should be maintained at the low end of the saturation index for at least 28 days to prevent white or gray streaking and / or cloud like formations.
Avoid the use of low pH sanitizers for 28 days to allow the cement to cure or run the pump and filter 24 hours per day if low pH sanitizers are required.
Do not add salt or other mineral based sanitizers during the initial 28-day cure.
Soda ash will bring pH up and Sodium Bicarbonate will bring Alkalinity up.
Pool finishes are susceptible to the same stain and scale build up as kitchen and bath fixtures. Tile and glass needs chemical cleaning and scrubbing to maintain that new look. Brushing and a conscience water balance program along with the regular moderate use of sequestering agents prevent phenomenons associated with water. Surface checking or crazing is inherent to some degree in all cement products. This is a normal occurrence and is not considered a deficiency. Dark or pigmented finishes require a much if not more attention than white background finishes.
Well water can add additional challenges. Pay extremely close attention to alkalinity and sequestering agent. Always add chemicals to water never water to chemicals.
Failure to follow the manufacturers instructions may cause an uneven cure. This can result in an irregular surface exposure, hydrations problems and / or staining which is not a result of the plaster manufacturer or the applicator.
- 1 gallon of 20 Baume Muratic Acid will lower the alkalinity approximately 50 ppm in a 15,000 gallon pool.
- Jack’s Magic Blue has a test kit for accurate monitoring. See jacksmagic.com
- Calcium or alkalinity levels too low can leach calcium from the cementitious finish.
- National Plasterers Council Technical Manual Revised: February 2002.
- Hydration is trapped moisture commonly referred to as mottling in cement pool finishes. This is not a product defect and is correctable with the quality water maintenance. See tech manual “Pool Surfaces 6th Edition”.
- Minor modifications may be necessary due to environmental or jobsite conditions. Please consult the Manufacturer for recommendatio