Acid Wash

[TigerHawk]

Going to paint our pool for the first time this year---the pool has been painted, this is my first time painting it--and I'm wondering about the acid wash procedure. Can / would it be recommended to load up the acid mixture into my pressure washer and spray down the pool or do you think the pressure washer would damage the plaster? Or, is it just as easy to apply the mixture with a watering can and scrub the surface with a brush? I don't want to harm the plaster or completely strip the old paint, but at the same time I would like to complete the wash part of the job within a couple days time while still accurately preppig the surface---we live in Iowa and spring time tends to be rainy so I need to wash the pool and cover it with a tent to keep rain, leaves and critters out before and during the painting and curing process.

[Pool Help]

Firstly don't use your pressure washer. All decent pressure washers have brass or aluminum pumps. The acid mixture will eat through it in no time, wrecking your pressure washer.

Acid washing is really quite simple. This is how we do it.

1. dilute one part muriatic acid with one part water (adding the acid to the water)
2. dip a soft brush into the solution and brush evenly over the walls
3. depending on the amount of build up to be removed, rinse after 30 seconds to 3 minutes
4. repeat in localized areas if necessary
5. now repeat on the floor. This may not always be necessary as the acid from the walls tends to slosh around the floor.

You don't really need to scrub the surfaces - the acid does the cleaning for you. A 20,000 gallon pool shouldn't take more than a few hours to acid wash completely.

Make sure you wear a mask and waterproof footwear!

[bookwoman]

Can you tell me about how much acid to use for a 20,000 pool?

[pine@telkomsa.net]

Going to paint our pool for the first time this year---the pool has been painted, this is my first time painting it--and I'm wondering about the acid wash procedure. Can / would it be recommended to load up the acid mixture into my pressure washer and spray down the pool or do you think the pressure washer would damage the plaster? Or, is it just as easy to apply the mixture with a watering can and scrub the surface with a brush? I don't want to harm the plaster or completely strip the old paint, but at the same time I would like to complete the wash part of the job within a couple days time while still accurately preppig the surface---we live in Iowa and spring time tends to be rainy so I need to wash the pool and cover it with a tent to keep rain, leaves and critters out before and during the painting and curing process.

[Marc]

How do you get the acid out of the pool after you wash it? Should I do this while washing it?

[DeShaw Pools]

Neutralize the pooled acid/water with sodium bicarbonate (baking soda) or soda ash. Initially it will react by dramatically foaming...as the pH approaches neutral this will dissipate. Use phenol red drops to confirm a neutral pH, then the solution can be safely pumped to black water.

[phl_stv]

So would using a pressure washer after the acid is applied help loosen/remove the stainns from the pool surfaces? I currently use the pressure washer to remove the algae that grows on the pool walls before I start treating the water every spring...

[ddeville]

How do you get the acid out of the pool after you wash it? Should I do this while washing it?

[mr_clean]

when doing a acidwash you need a sump pump/vac hoses to remove the the mix when acidwashing. You can go to your local pool store and normally rent these things which you will need to drain your pool.
you need to plan this out before starting, where your going to dump the mix? if you have a DE filter you may have a P-trap you can put drain hose in. Depending on city rules you can drain at your curb but talk to your pool store they should know if they do this service.
Make sure you have some kind of breathing protection so you are protected from the fumes.
Once you have drained your pool, you want to take your water hose and rense off the pool walls and floor of any debris.
Remove your pool light so you can rense out the hole and not get any drip marks after acidwash.
when acidwashing before you start pouring you always make sure the area of wall your doing is wet and the hose is pouring water on the floor of the pool to protect it also.
when mixing acid and water you do a 50/50 mix into a plastic watering can. you want to cut the tip of the water can off so it pours out like your hose, you do not want the rain tip on.when pouring you always start at the middle of your pool tile that is at the top of your pool by your coping and pour down so your plaster burns even.
Always keep your water hose on as you do not want the sump pump to run dry and it help to weakin the mix as it puddles and drains out. Once you pour do not rense until it stops foaming then rense with water hose from the top down in the same direction you poured.
You do this all the way around your pool and depending on how it looks to you will depend on if you do it a second time.
If you see green stains it is copper and depending how long and deep they have gone into your plaster will depend om if they come out.
If you see a brown stain or ring around the pool its iron and comes off much easier. Once your done rense the plaster down really good.