White Cliffs of CHALK!

[Tecman]

This 6-year old concrete pool that I've "inherited" has lots of chalking on the surface. Anything I can do about that? I know that it was painted about a year and a half ago.

I was thinking of washing it with a 1:10 solution of muriatic acid & water but I really don't want to hurt the concrete. Re-painting is out of the question at the moment - I simply cannot afford it.

The pool has just been emptied so it seems to be a good time to deal with this.

[mr_clean]

This is caused by the pool being painted & the chemicals not balanced correct, chemicals eat away at paint and when brushing walls the water can become cloudy with chalk looking clouds.
You can acid wash pool but if paint is clouding water already, I would suggest repainting pool with a good epoxy paint after, which should last 4-5yrs with correct chemical balance. 2-gallons is normally $175 range

[Tecman]

Thank You mr_clean

The pool is not becoming cloudy at this point and I know the chemical balance was monitored but I guess not carefully enough!

What would you recommend for an acid wash? I'd just like to get rid of the chalking but, I said earlier I just cannot afford to paint it at this point - it has to last at least another 6-8 months.

I really appreciate your advice - I'm in Costa Rica and finding reliable advice on anything (in English) is difficult.

[mr_clean]

for a painted pool 60-40, water/acid mix should be good. Remember it's a two man job with one pouring from bottom of tile down the side and the other brushing the wall with acid on it, then rinsing that area with a water hose right after brushing. At the same time you will need sump-pump at the deep end with hose going to outlet which would got to sewer.
Remember this could cause paint to look different in different areas of pool depending on chemical damage to paint and always wear some kind of breathing protection when doing acid wash. I would inspect walls also to make sure plaster is in good enough condition to handle acid wash, look for pitting.

[Tecman]

Thanks! I'll give this a try and post my results afterwards for future reference.

[Tecman]

Okay - I tried the 60/40 mixture as you suggested. It didn't really make all that much of a difference whether I brushed with or without the acid. Brushing seemed to be the key.

So, afraid of trying a stronger acid mix, and being the lazy sod that I am, I tried a pressure washer. Worked like a charm. While it did not do "magic" things and the paint does not look new, it did remove most of the chalking and did no damage to the surface.

So now I'll fill it back up, monitor the chemical balance daily, and hope that it survives until next dry season when I can afford to paint it.

Hats off to you mr_clean - I appreciate your help!