Acid wash or re-surface

william13

Gold Supporter
Oct 1, 2022
812
south florida
Pool Size
20000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
Pool between 7-10 years. Not sure. Possibly acid washed 1-2 x in past. (not sure). Pool guy says I can acid wash again because of both dark and light stains. How do I know if I reached my limit on acid washing and need to go with the resurfacing? Is there something I can inspect further?
 
Pool between 7-10 years. Not sure. Possibly acid washed 1-2 x in past. (not sure). Pool guy says I can acid wash again because of both dark and light stains. How do I know if I reached my limit on acid washing and need to go with the resurfacing? Is there something I can inspect further?
Depends on your goals. 10 years isn’t that old. Acid wash will make the surface rougher and shorten its lifespan. Is doing nothing an option?
 
Depends on your goals. 10 years isn’t that old. Acid wash will make the surface rougher and shorten its lifespan. Is doing nothing an option?
All options on table but wife constantly remarks on its appearance. At some point I know I will need to resurface so do that now or shorten life span and resurface latter is one question. The other question is Would acid washing even work with age of pool (lets say 10 years) and lets pretend its been washed 2 x in past.
 
All options on table but wife constantly remarks on its appearance. At some point I know I will need to resurface so do that now or shorten life span and resurface latter is one question. The other question is Would acid washing even work with age of pool (lets say 10 years) and lets pretend its been washed 2 x in past.
How large is the pool? And do you have 15 to 20k to replaster it?
 
How large is the pool? And do you have 15 to 20k to replaster it?

How large is the pool? And do you have 15 to 20k to replaster it?
I'm going to get back to you on size but approx 20 x 40. Regarding price I guess I will do what is best to maintain it.
 
Here we go! Going from left to right
1. shows very light stains almost looks like clouds
2. Is the diamond brite or equivalent I have
3. steps have brown stains
4. entire pool roughly 20 x 40 with max depth 5 feet
5. Mottled (this one gives the best view of all the colors on bottom)
6. brown discoloration stair
 

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Read up on this. At first glance it looks like Copper to me. Do you use algaecide, minerals or other "blue" products?

 
It looks like it is probably metal stains.

Most likely, it is a combination of copper, silver and iron.

Jack’s #2 Copper and Scale Stuff is sulfamic acid and it might work.

Sulfamic attacks copper, so you have to take the heater offline before adding sulfamic acid.

After doing the treatment, you should drain and refill if it is safe to do so.

Draining a pool can result in the pool popping out of the ground and floating.


So, you have to be very careful and check the ground water level before draining.

You should get professional advice before draining to verify if it is safe to drain and refill.

 
When the pool is drained, you can use diamond sanding pads to polish the plaster to remove any remaining stains and smooth out the plaster.

You should get professional advice before draining to verify if it is safe to drain and refill.
 
Brown is usually iron, but silver can also be brown.

Silver stains look different from iron stains and your brown looks more like silver stains.

Copper and silver can come from an ionizer or algaecides.SilverAlgaecide.jpg
 
Acid washing can work, but it makes the plaster very rough.

I would probably try sulfamic first and then sanding and then maybe acid only as a last resort and then follow by sanding to resmooth the plaster.

Here is a thread where they used acid washing and they were happy with the result, but they did not report about the roughness.


Copper before 2.jpgcopper before.jpgCopper before acid wash.jpgCopper after acid wash 2.jpgCopper After Acid Wash..jpg
 
Wow everyone. Thanks. This is going to take more than a minute to digest and understand and I like the possibilities of having alternatives. My stairs show "brown" perhaps I can use that as a test site to see if products work?
Why are some areas very bright and other dark. Are the bright areas the areas that are unaffected? For example Image 1 on left?
 
Metal stains can be very blotchy and unevenly distributed.

Sometimes stains are precipitated by products like calcium hypochlorite being broadcast and causing stains where the calcium hypochlorite hits the plaster.

Metal stains are very unpredictable.
 
Note that acid eats away the cement and it can seriously damage the plaster, so it is not something to use without being aware of what the adverse effects can be.

Cement holds in the aggregates, which are usually marble (Marcite), quartz or pebble.

The aggregate is usually not affected except for marble aggregate.

When the cement gets dissolved, the aggregate gets exposed and makes the surface very rough and the exposed aggregate can fall out into piles of sand or pebbles.
 
Here we go! Going from left to right
1. shows very light stains almost looks like clouds
2. Is the diamond brite or equivalent I have
3. steps have brown stains
4. entire pool roughly 20 x 40 with max depth 5 feet
5. Mottled (this one gives the best view of all the colors on bottom)
6. brown discoloration stair
If you look carefully at the trim tile on the steps, you will see what remains of the "cream" that makes plaster smooth. If it was acid-washed twice (which it looks like) that is usually the limit, and the last one was very aggressive. You should not see the aggregate in the plaster like picture 6435. Do it again and you will not like what it does to your feet or bathing suits next summer. A rough surface like that is also a haven for algae, regardless of chlorine levels.
 

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