Why Acid Wash New Quartz Pool Finishes?

[lrk322]

I know This is an old thread, but I found it due to my similar concerns with the acid wash. I'm having QuartzScapes Regular Series: Super Blue done on a replaster this week. My previous plaster lasted 25 years and don't want to shorten the life of the quartz finish with acid. The pool guy is open to skipping the acid wash but I'm hesitant to tell the plaster guys to apply the plaster differently than they normally would. Can I simply instruct them to do their normal process, and just skip the acid at the end? I understand I'll likely need to be backwashing my filter a lot due to the amount of excess that comes off the walls. I'm not concerned with the appearance, we won't be swimming for 5 months in central texas. I'm okay with the quartz finish revealing itself over time.

https://www.nptpool.com/pool-finishes/all-finishes/qsrgssb/

 

[an1vrsy]

Welcome to TFP! I can not speak on why or how acid washing is done to quartz finishes. I know that I saw that onbalance post and decided I did not want an acid wash. Fortunately, for me my plaster contractor did not do acid washes after completing the job anyway. We selected a similar color and love the look.

s-facing-pool.jpg

• an1vrsy
• Feb 27, 2022

e-facing-spa.jpg

• an1vrsy
• Feb 27, 2022

 

[Bperry]

I know This is an old thread, but I found it due to my similar concerns with the acid wash. I'm having QuartzScapes Regular Series: Super Blue done on a replaster this week. My previous plaster lasted 25 years and don't want to shorten the life of the quartz finish with acid. The pool guy is open to skipping the acid wash but I'm hesitant to tell the plaster guys to apply the plaster differently than they normally would. Can I simply instruct them to do their normal process, and just skip the acid at the end? I understand I'll likely need to be backwashing my filter a lot due to the amount of excess that comes off the walls. I'm not concerned with the appearance, we won't be swimming for 5 months in central texas. I'm okay with the quartz finish revealing itself over time.

https://www.nptpool.com/pool-finishes/all-finishes/qsrgssb/

Lots of times new finishes are designed to have the acid wash because they don’t bother removing the cream from the top to expose the aggregate. Diamondbrite has an alternate process called a water wash and you might ask them about that and see if there’s something similar for your finish. The diamondbrite instructions say that it’s more technical to perform and so not as many people do it that way.

 

[lrk322]

@Bperry my contractor mentioned that he could have them try doing a light pressure wash instead, I wonder if this is similar to the water wash. @an1vrsy lovely pool btw, did he do his normal process and then just skip the acid wash? My contractor is telling me that it will be blotchy and the milk will be coming off for a while. Which I'm fine with, if it increases the longevity. I'm not really concerned with seeing the aggregate.

@onBalance would it be okay for the guys to do their normal process and then just skip the acid wash at the end? My contractor is thinking they'll lightly pressure wash instead, but it sounds like that may not be ideal either. I'm hoping they can just do their normal process and skip the acid wash part as asking them to do any variation on how they normally lay the plaster, I worry they may mess up their process.

 

[Bperry]

@Bperry my contractor mentioned that he could have them try doing a light pressure wash instead, I wonder if this is similar to the water wash. @an1vrsy lovely pool btw, did he do his normal process and then just skip the acid wash? My contractor is telling me that it will be blotchy and the milk will be coming off for a while. Which I'm fine with, if it increases the longevity. I'm not really concerned with seeing the aggregate.

@onBalance would it be okay for the guys to do their normal process and then just skip the acid wash at the end? My contractor is thinking they'll lightly pressure wash instead, but it sounds like that may not be ideal either. I'm hoping they can just do their normal process and skip the acid wash part as asking them to do any variation on how they normally lay the plaster, I worry they may mess up their process.

The water wash sounded like wiping the grout off of tile with a sponge after the grout had set up a bit. Skip down the the “exposure” section near the end of the list.

Diamond Brite® - SGM, Inc.

Diamond Brite® finishes are blends of selected quartz aggregates and fortified white Portland cement ideal for new or re-finished swimming pools. Diamond Brite® finishes are factory blended to provide the pool owner with an extremely durable and attractive alternative to traditional pool...

www.sgm.cc

That said, I don’t think an initial acid wash is going to reduce the life of the plaster as the whole point of both the water wash and the acid wash is to remove the top layer of plaster cream. The process purposely has that layer on top so that it can be removed later. If you don’t want the aggregate, it would be cheaper to just use normal plaster. The warnings against acid washing are for fixing pool water staining caused by bad maintainance without address why the stains got there originally.

 

[onBalance]

I think it is a good idea to ask the plastering company to apply and trowel the pool as usual, and then on the last and final hard troweling, they could easily remove any cement cream or "fat" (as it is often called) that collects on the trowel and place that "soft creamy" material into their trowel bucket. That is how I learned to plaster and trowel pools. And that is what I asked the plaster company to do for me. (I wasn't able to trowel my own pool because of my bad back.)

Even if some of the cream is not removed from the plaster surface, the residual will probably slowly wear away in a couple of years and expose more of the quartz aggregate color, which is what occurred with my pool.

Using acid with any process is a mistake. Waiting a few hours and simply rinsing with water and slightly brush or sponge the surface would be a better option than using acid. Less damage, less likely to cause streaks, and less likely to cause mottling. And note that an acid treatment could always be performed a year or two later if there was a need.

Maybe the plaster company would reduce the price a little for not having to perform an acid washing. ;-)

 

[lrk322]

I think it is a good idea to ask the plastering company to apply and trowel the pool as usual, and then on the last and final hard troweling, they could easily remove any cement cream or "fat" (as it is often called) that collects on the trowel and place that "soft creamy" material into their trowel bucket. That is how I learned to plaster and trowel pools. And that is what I asked the plaster company to do for me. (I wasn't able to trowel my own pool because of my bad back.)

Even if some of the cream is not removed from the plaster surface, the residual will probably slowly wear away in a couple of years and expose more of the quartz aggregate color, which is what occurred with my pool.

Using acid with any process is a mistake. Waiting a few hours and simply rinsing with water and slightly brush or sponge the surface would be a better option than using acid. Less damage, less likely to cause streaks, and less likely to cause mottling. And note that an acid treatment could always be performed a year or two later if there was a need.

Maybe the plaster company would reduce the price a little for not having to perform an acid washing. ;-)

@onBalance thanks very much for this information.

Just to confirm I have all of the steps down-

1. the last hard trawling is completed where the cream is removed
2. they wait two hours (they'll be doing my neighbor's pool too, so they could come back).
3. They rinse with water and slightly sponge or brush the surface (not pressure washing?) (ideally water with baking soda so it isn't acidic)
4. Wait to fill the pool 6 hours from the point the hard trawling is completed.

Thanks again for all of this info and thank you @Bperry for the info as well.

 

[onBalance]

Just to be clear, I still would prefer that no washing is performed at all. And there is no need to do a washing if the cream is being systematically removed while troweling. But if you can't get them to forego the washing, then that is better than using any acid. Yes, a baking soda wash is the ideal.
Btw, please test your tap water for pH, alkalinity, and calcium hardness and let me know. Let's also consider the chemical startup program.

 

[an1vrsy]

@an1vrsy lovely pool btw, did he do his normal process and then just skip the acid wash? My contractor is telling me that it will be blotchy and the milk will be coming off for a while

The plaster contractor does not do acid washes after quartz application. For us, by selecting a lite color finish with blue quartz crystals, we do not have blotchy or mottling. As far as I know, darker colors are more prone for displaying those issues. Good luck!

 

[onBalance]

The plaster contractor does not do acid washes after quartz application. For us, by selecting a lite color finish with blue quartz crystals, we do not have blotchy or mottling. As far as I know, darker colors are more prone for displaying those issues. Good luck!

Sounds like you made two good decisions; choosing a light color finish (far better than a dark color pigment), and choosing a knowledgeable and good plaster contractor.

 

[lrk322]

Thanks everyone for all of this input. @onBalance thanks for all of your advice. If the weather is going to be overcast, 60-70 degrees with about 60% humidity. Is there a certain number of hours I should wait before filling? I have my tap water measurements below, thanks again!

My Alkalinity is 140, PH is 7.2 or 7.0 (I'll need to check in sunlight tomorrow, did it in the house tonight) and my calcium hardness is between 150-180 depending on how you read the blue. I think 180 looked the most blue to me.

 

[Bperry]

Thanks everyone for all of this input. @onBalance thanks for all of your advice. If the weather is going to be overcast, 60-70 degrees with about 60% humidity. Is there a certain number of hours I should wait before filling? I have my tap water measurements below, thanks again!

My Alkalinity is 140, PH is 7.2 or 7.0 (I'll need to check in sunlight tomorrow, did it in the house tonight) and my calcium hardness is between 150-180 depending on how you read the blue. I think 180 looked the most blue to me.

For the CH test you keep going until the drop doesn’t make it any more “blue-er”. Don’t try judging what blue is more blue.

 

[onBalance]

Your tap water is pretty decent for filling plaster pools, nearly ideal. So my suggestion is to ask the plastering contractor to skip the "washing" altogether, and then wait about 4 to 6 hours before starting to fill the pool. Also, ask to limit the amount of calcium chloride (hardening accelerator). Tell them you will pay a little more for taking an extra hour to plaster your pool. They really shouldn't add any because of using a color pigment. And hopefully, they will use a blue pigment that is colorfast.

Sounds like the weather will also be ideal. I doubt that there will be much "milk" (plaster dust). So I disagree with the plaster guy about that.

Here is something you can read about plastering pools. And you might want to search my other articles for further info.

How to Ensure a Quality Pool Plastering Job

For pool owners, pool builders, remodeling companies, and pool plasterers that want the best chance to obtain a quality and discoloration-free pool plaster job (including white, color, and quartz aggregate pools), the link below is to an article in WaterShapes (a pool industry publication) that...

www.troublefreepool.com

 

[OBenthooo]

Welcome to TFP! I can not speak on why or how acid washing is done to quartz finishes. I know that I saw that onbalance post and decided I did not want an acid wash. Fortunately, for me my plaster contractor did not do acid washes after completing the job anyway. We selected a similar color and love the look.

s-facing-pool.jpg

• an1vrsy
• Feb 27, 2022

e-facing-spa.jpg

• an1vrsy
• Feb 27, 2022

This looks amazing. Can you give me the details on the brand/color used? Who was your contractor? TIA!