Swimming Pool Paint Troubleshooting Guide

Why is my pool chalking?/Why is my pool hazy?

Chalking Paint is actually a problem with your pool chemistry - rather than your paint. If the balance of the water in your pool is not maintained correctly – calcium in the water can “fall out” leaving behind a chalky residue that may cloud up the water of your pool and settle on your pool walls. This is typically a result of the pH level of the pool climbing too high, or the total alkalinity dropping too low, the scale left behind can feel greasy and can easily be mistaken for paint that is breaking down.

If the pool becomes hazy, no amount of shocking can clear the water, in fact - the use of hypochlorite shock tablets can make chalking much worse. Fortunately; the water balance of your pool is simple to rectify. If your pool is chalking badly, the below can be used to bring your water chemistry back in line:

1. Ensure your total alkalinity stays within 125 - 150 ppm.

2. Use a scale and stain control agent (making sure you follow manufacturer’s instructions).

3. Use a Clarifier or Flocculent to make the most of your water filter.

4. Use a finer grade water filter

5. For 7 days, run the filtration system of your pool for 16 – 20 hours to clear the water

6. Brush the walls of your pool

7. Keep the calcium level at 175 - 225 ppm.

The above should clear your pool water, and monitoring and maintenance should prevent this occurring in the future. Regular brushing of the pool walls, monitoring of the pH and alkalinity of the water, and the use of scale control agents (particularly during the busy swimming season) should keep your pool chalk-free throughout the summer.

Why is my paint fading/stained?

While all paints will fade over time, if your pool is fading earlier than expected something else may be happening. If you have filled your pool earlier than the recommended 14 days, one of the things that may happen is a “blush” over the surface of the pool that looks like fading of the pool surface.

Another cause may be “shocking”, if Calcium hypochlorite has been used to shock your pool, the resulting calcium deposits can give a white bleached look to the paint film (see “why is my pool chalking?”)

Any inorganic components or metals in the water can stain your paint. Rust from your filter system may leave iron deposits on the surface of the film, causing staining. As these are indicative of superficial problems – the surface of the paint can be brought back by the following:

1. Thoroughly scrub the surface of your pool using soap and water to remove contaminants and surface dirt.

2. Use a weak solution of Muriatic acid (no more than 3%) and wet the surface of the paint to remove deposits and iron staining.

3. Extremely corrosive water can ultimately cause deterioration or breakdown of a paint film over a period of years – be sure to say vigilant in checking your water conditions

4. If the staining is severe and has not removed by washing, you may want to repaint the surface – this will however need preparing by rubbing back to remove the staining before painting. Failure to do so will result in the stain leeching back through to your topcoat after some time.

Remember: Always leave at least 14 days after painting before filling your pool

Why is my paint blistering?

Blistering can be due to a number of causes, the main three are outlined below:

1. Large blisters across the entire surface of the pool (walls and floor)

Blistering is typically due to poor preparation of substrate, damp in the substrate or solvent entrapment. If contaminants are present on the surface of the paint prior to painting these cause “pockets” in the paint which burst once the pool is filled. Similarly, if an existing paint is not compatible, the solvents in the new topcoat can react with the basecoat causing bubbles and blistering. If the substrate has not been allowed to dry fully prior to painting, or has a damp problem, the water within the substrate will try to push the paint away from the surface, this again can cause blisters and bubbling. Often when these blisters are burst you may find discoloured water trapped within them – this is indicative of water being pulled through the substrate and forcing away the topcoat. If a paint has been applied too thickly, or the pool has been filled too soon – once the pool has been filled, the entrapped solvent will cause blisters in the film.

2. Large blisters across the base of the pool, potentially filled with discoloured water

These typed of blisters are due to the residual damp in the substrate. If a surface is not completely dry prior to painting the resulting moisture can cause the paint to fail to adhere, or in some occasions bubble and blister as the moisture attempts to break through the paint film and escape the surface. Typically when these blisters are restricted to the base of a pool, particularly in the base of an In-ground pool, it is indicative that water has penetrated the base concrete.

3. Several small blisters (less than 10mm)

Several small blisters can be attributed to excess heat at the time of painting. This is a particular problem with external swimming pools, the heat combined with direct sunlight can cause boiling of the paint film. The boiling reduces the integrity of the paint film, creating pinholes and allowing water to penetrate the paint resulting in small blisters.

How do I repair the blisters?

While there are numerous causes for blisters, when they occur, best practice is to remove the coatings down to the bare substrate and treat as new.

In the case of localised small blisters as a result of excess heat it may be suitable to conduct a spot repair by abrading the areas where the blisters are localised, and then feather edging into the existing coating, ensuring at least a 50mm overlap between coats.

Why is my paint peeling away?

Peeling Paint is due to a lack of adhesion between the paint and the surface beneath. Typical causes are:

1. Contamination – Before painting always thoroughly clean the surface as the oil, dust etc. can interfere with the paint. Typical contaminants in pools are the greases and oils from sunscreen or cosmetics, laitance from the concrete surface or grime and chalking from the pool surrounds.

2. Incompatible paints – It’s particularly important to choose a compatible paint, incorrect paints can fail to adhere or react with the existing coating its extremely important to choose the correct paint for the correct pool.

3. Overcoating times – Overcoat times must be adhered to. Whilst Swimming Pool Paint can be left a few days between coats, if left more than 7 days the surface will need to be abraded to provide a key. If the surface is allowed to fully harden (ie 7-14 days) before the final topcoat, the properties that make the paint resistant to pool water will make it resistant to itself.

4. Surface preparation - Skipping surface preparation can result in all manner of problems, it is the most crucial step in any painting job and failure to prepare the surface for painting can result in the whole system failing.