Running out of options to restore plaster color

[xtexan86]

So, long story short, I had my new pool plastered in May. After months of stressing over the color, I opted for a DiamondBrite Quartz Manzanita. The color turned out perfect. (see first picture). Jump ahead to August. Pool service guy screwed up and poured too much muriatic acid in water. Left a black stain on the front shelf right under the water jet. Got supervisor out and he was able to "fix" the problem, however, I gradually began to notice that lovely blue was turning into a blah grey. (see middle picture). Deep end of pool was now more of a greenish color and water was very cloudy. (Best way to judge color difference is compare the blue tile over the rear shelf - it matches blue on shelf in first picture but stands out in the middle picture). I needed to leave home shortly after supervisor arrived but could notice a little difference had occurred. Once I came home water was much clearer but the plaster is still overly grey. Unfortunately, these pictures make the pool look great, in real life the grey is much more prevalent. Supervisor probably knows what he's doing, says higher pH (along with some other factor) is key to trying to reduce the effect escaping calcium is having on the plaster. Plaster guy says acid was responsible for drawing out the blue pigment. Anyway, I'm done with trying to convince myself to be satisfied with this "new" color. I have tried some sanding and even using a pumice stone to see if sanding the plaster can reveal the original color. All it does is just get darker, but at least it's a dark blue. Replastering will cost me more than the original coat, around $5000. I think the pool service company needs to cover this so I let the supervisor know I wanted him to come by again and I'll see what his reaction is. Is there anything mechanical that might work to reveal the original plaster color? I'm leaning towards using some "diamond sanding blocks", like hand-held sanding sponges, or purchasing a pool plaster polishing/sanding pad and going at it with an angle grinder.

 

[ajw22]

I think your only option is sanding the plaster with 80/100 grit wet dry sandpaper and seeing what color it reveals.

Let’s see if @onBalance has thoughts.

 

[xtexan86]

I think your only option is sanding the plaster with 80/100 grit wet dry sandpaper and seeing what color it reveals.

Let’s see if @onBalance has thoughts.

I tend to agree but how do you sand plaster this way? Just wrap the paper around a block of some sort? When I did a small area on the back shelf yesterday, it kicked up quite a bit of dust. That could be because I haven't brushed the pool with a wire brush for a few weeks. Anyway, if you look at the middle pic, you can see an area of darker blue to the extreme right of the front step. That's where I aggressively sanded the spot back late Aug/early Sept. The attached photo shows the original color of the plaster.

 

[onBalance]

I am hoping that the fading of the blue color (and turning grey) is not due to being bleached by chlorine. But if the change to grey is only in a small area and not everywhere else, then perhaps that is not the problem.

If the discoloration area is only a small area, then hand sanding with sandpaper as Allen suggested is the best option to restore the color. It will be darker for a while, but in time, the dark color should fade somewhat to match the rest of the plaster finish. The other option is to drain the pool and power-sand the entire pool. Acid treatments do not work in the long run! They only work temporarily.
A close-up photo of the problem area might be helpful.

 

[xtexan86]

I am hoping that the fading of the blue color (and turning grey) is not due to being bleached by chlorine. But if the change to grey is only in a small area and not everywhere else, then perhaps that is not the problem.

If the discoloration area is only a small area, then hand sanding with sandpaper as Allen suggested is the best option to restore the color. It will be darker for a while, but in time, the dark color should fade somewhat to match the rest of the plaster finish. The other option is to drain the pool and power-sand the entire pool. Acid treatments do not work in the long run! They only work temporarily.
A close-up photo of the problem area might be helpful.

The fading of the blue pigment affects the entire pool, not just one area. It is very noticeable on the shallow shelf areas. This color change happened within about 2 weeks after pool service guy overdosed the water with acid. I took a sample to Leslie's and they said the acid content was 10x over normal levels. What I don't understand about the properties of plaster, is how deep can pigment be lost? It's strange that sanding tends to reveal a darker blue color. Also, if I drain the pool (not a hard decision because of it's size) how would I "power-sand" it? Thanks!

 

[onBalance]

Sometimes a plaster mix will have two different colors (pigments) added. One a blue and the other a grey. Grey pigments are generally colorfast, but some blue pigments are not and will bleach and fade out leaving the grey pigment unaffected and the dominant color.
Sanding a faded (blue) plaster finish will remove the faded (blue) plaster and expose the currently unaffected plaster and original and initial (blue) color. But in time, the newly exposed plaster and blue pigment will likely become bleached again, leaving the grey unaffected again.
On the other hand, if the problem was caused by very aggressive water, due to acid additions, then that causes the plaster to become etched, and later, porous. A porous cement surface is typically much lighter in color, even white. The best way to make a plaster surface smooth and non-porous is to sand and polish the surface. Most plaster companies have power-sanders and can help provide info with that program.

At this point, we need to know what Leslie's water test results were, and what your current water test results are. There may be some future debates with the involved parties.

One other thing, colored plaster will never remain exactly the same over time.

 

[xtexan86]

Yes, yes, yes!!!! So I got real aggressive and scraped away a small spot of the plaster right underneath the tile. My "blue" is still there! Looks like I'll just need to drain pool and polish off the plaster surface until I see the original blue. Sorry, can't get the pic to orient the other way but you can see the diff in color.

 

[xtexan86]

Sometimes a plaster mix will have two different colors (pigments) added. One a blue and the other a grey. Grey pigments are generally colorfast, but some blue pigments are not and will bleach and fade out leaving the grey pigment unaffected and the dominant color.
Sanding a faded (blue) plaster finish will remove the faded (blue) plaster and expose the currently unaffected plaster and original and initial (blue) color. But in time, the newly exposed plaster and blue pigment will likely become bleached again, leaving the grey unaffected again.
On the other hand, if the problem was caused by very aggressive water, due to acid additions, then that causes the plaster to become etched, and later, porous. A porous cement surface is typically much lighter in color, even white. The best way to make a plaster surface smooth and non-porous is to sand and polish the surface. Most plaster companies have power-sanders and can help provide info with that program.

At this point, we need to know what Leslie's water test results were, and what your current water test results are. There may be some future debates with the involved parties.

One other thing, colored plaster will never remain exactly the same over time.

Thank you for your reply. As you can see with my latest post, I think the only remedy I have at this point is to power sand and polish the plaster until the original blue is revealed. I probably only took off about 1/16th of an inch, if that so I won't have to remove too much plaster material. And I agree, colored plaster will fade over time, but this color change literally happened within a month's time so was directly attributable to the pool service company's actions.

 

[onBalance]

I need to explain better because this situation is complicated.
No, it hasn't been determined why the blue color has changed or faded. The original dark blue and grey color may "lighten" somewhat when the pool water is overly aggressive, but the "blue" will still be present and show. It will just be a slightly lighter "blue." The blue color won't disappear in aggressive water (high acid).

The photo above looks like the "blue" is completely disappearing. That may be due to the wrong blue pigment being added to the plaster mix. If the blue color pigment is colorfast, then the blue color won't disappear within a month, or even a year. The fact is that aggressive water will quickly expose the original and underlying dark blue color. It doesn't cause an immediate lightening or loss of color. Sanding the plaster does a similar thing by exposing the original and underlying plaster color. But the blue color will disappear again if the pigment is being bleached, and which has nothing to do with whether the water is balanced or very aggeressive.

You should sand some more plaster areas and wait to see if the blue color fades again within a month while the water is kept balanced. Again, please provide the pool water test results that I asked for, and a close-up photo of the original black spot discoloration.

 

[xtexan86]

I need to explain better because this situation is complicated.
No, it hasn't been determined why the blue color has changed or faded. The original dark blue and grey color may "lighten" somewhat when the pool water is overly aggressive, but the "blue" will still be present and show. It will just be a slightly lighter "blue." The blue color won't disappear in aggressive water (high acid).

The photo above looks like the "blue" is completely disappearing. That may be due to the wrong blue pigment being added to the plaster mix. If the blue color pigment is colorfast, then the blue color won't disappear within a month, or even a year. The fact is that aggressive water will quickly expose the original and underlying dark blue color. It doesn't cause an immediate lightening or loss of color. Sanding the plaster does a similar thing by exposing the original and underlying plaster color. But the blue color will disappear again if the pigment is being bleached, and which has nothing to do with whether the water is balanced or very aggeressive.

You should sand some more plaster areas and wait to see if the blue color fades again within a month while the water is kept balanced. Again, please provide the pool water test results that I asked for, and a close-up photo of the original black spot discoloration.

So, I didn't obtain a written result from the water test at Leslie's. Probably wasn't thinking that day or just felt all I needed was to confirm there was excess acid in the water. Since I leave pool maintenance to "professionals" I have no way to provide you with what the current chemistry of my water is.
Attached is a picture of the first problem I had when the floating chlorine dispenser got stuck over a shallow step and left the spot you see. It confirms your theory that chlorine can bleach the plaster color but this happened only because the tablet dispenser was too close to the step. The supervisor came out and was able to remove the stain. Now this occurred one month after the pool was filled with water for the 1st time so end of May. You can see the blue is still present. The other view is the plaster's condition at the end of August. The 2nd picture was taken at the end of July. Clearly the blue pigment has significantly diminished and you can see it's just all grey. I didn't take photos when the blackened stain on the shelf in front of the water jet happened but I believe that was around the middle of June. It looked very similar to the black spot you see on the front step. That stain appeared overnight after I actually saw the technician dump (what I didn't realize was the acid then) liquid directly from a 1 gallon jug, into the pool. The supervisor even did his own water test and confirmed there was at least 4x the amount that should've been in the pool. Remembering details is hard, but I would say within a week or two later was when the color change in the plaster became very noticeable, so I don't think the color change was attributable to bleaching from chlorine.
You mentioned the possibility of the "wrong pigment" added to the plaster. While that is possible, is it really likely? The plaster company is either a 4th or 5th generation outfit out of Sacramento CA. I would hope if you're in business that long, that you know what you're doing and wouldn't carry a color dye or brand that practically loses its tint within 2 months of application. I do like your suggestion of sanding a few more spots and giving it some time to see what happens. I'm really hoping the supervisor will come by early next week so I can run these issues/suggestions by him again. He discontinued the use of the chlorine dispenser about a month ago so I'm not sure how the water chemistry is being maintained as the tech only comes out 1 every 2 weeks, but my water looks fine (although a bit cloudy presently).

 

[ajw22]

Get your own test kit. Either the Test Kits or the Taylor K-2006C. You need to take control of your water chemistry and be able to find out exactly what is happening with your new pool.

You mentioned the possibility of the "wrong pigment" added to the plaster. While that is possible, is it really likely? The plaster company is either a 4th or 5th generation outfit out of Sacramento CA. I would hope if you're in business that long, that you know what you're doing and wouldn't carry a color dye or brand that practically loses its tint within 2 months of application.

I am suspicious with all the supply chain issues and plaster shortages that there may be substitutions of product happening either knowingly or unknowingly. There have been reports of various colors being unavailable in some areas.

 

[xtexan86]

Get your own test kit. Either the Test Kits or the Taylor K-2006C. You need to take control of your water chemistry and be able to find out exactly what is happening with your new pool.



I am suspicious with all the supply chain issues and plaster shortages that there may be substitutions of product happening either knowingly or unknowingly. There have been reports of various colors being unavailable in some areas.

Yes, learning water chemistry is definitely on that to-do list but presently, I don't have any time to learn. Also, since this was a new pool, I wanted to have a "professional" monitor the start up (something the installer strongly recommended) and also be knowledgeable enough to handle any wild fluctuations that could happen in such a small pool. Obviously, I wasn't prepared for an experienced technician to screw up so bad and cause such a headache for me, but at least I have someone other than myself to hold responsible.

 

[ajw22]

As you are learning a "professional" in the pool business is a meaningless title with no assurance of any quality standards.

That is the reason for TFP existing since hundreds of thousands of pool owners have discovered that they are more knowledgeable to maintain their pools then the "professionals".

The sooner you take control the better off you will be. And don’t expect any Leslie employee to be a "professional" looking after your best interests.

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[onBalance]

Having 4 times too much acid added isn't providing the information needed. And acid does not cause a blue pigment to bleach out (disappear or fade away) while leaving the grey pigment intact. You might find out if your plaster mix contained both a blue and a grey pigment.

A chlorine floater can cause a dark spot just like adding acid directly over the plaster. Hence, that is why spots can turn a dark color in colored plaster (not with white plaster). Trichlor tabs are also very acidic. Thus, creating darker spots are usually an acid effect. When the blue pigment begins to disappear and doesn't affect the grey pigment is usually a bleaching effect of the non-colorfast pigment. Don't associate the two aspects with each other.

Non colorfast blue pigments are much cheaper than the (expensive) colorfast ones. And some plasterers don't/won't learn the difference and accept responsibility if the color fading is always blamed on chemical treatments.

 

[xtexan86]

Having 4 times too much acid added isn't providing the information needed. And acid does not cause a blue pigment to bleach out (disappear or fade away) while leaving the grey pigment intact. You might find out if your plaster mix contained both a blue and a grey pigment.

A chlorine floater can cause a dark spot just like adding acid directly over the plaster. Hence, that is why spots can turn a dark color in colored plaster (not with white plaster). Trichlor tabs are also very acidic. Thus, creating darker spots are usually an acid effect. When the blue pigment begins to disappear and doesn't affect the grey pigment is usually a bleaching effect of the non-colorfast pigment. Don't associate the two aspects with each other.

Non colorfast blue pigments are much cheaper than the (expensive) colorfast ones. And some plasterers don't/won't learn the difference and accept responsibility if the color fading is always blamed on chemical treatments.

Ok, I hear you but this info puts me in the dreaded position of "he-says, they-say." My plaster guy says acid will leach out the blue pigment, you (and it seems some other studies) say it doesn't yet he's the one responsible for my warranty. I can't find anything online that definitely states what kind of color pigment (whether colorfast or not) SGM/Diamond Brite uses in their exposed aggregate pool plaster products. I'm sure the plaster guy used a combination of colors for my pool, so no surprise that there's likely blue and grey pigment along with maybe black or some other color. I still haven't seen an explanation of why the pool plaster color remained totally fine until the acid incident, then seemed to quite quickly change. If chlorine bleaching is responsible, why didn't that happen much early on? Not trying to be argumentative but the timing of this occurrence is really impossible to ignore. Given all that, I'm emailing the plaster guy and will see what he says but I don't think I need a crystal ball to figure out what his position is going to be.

 

[onBalance]

The ppm amount of dissolved chlorine is relatively low. It is just reality that it takes many days and weeks to bleach colored plaster that contains non colorfast pigments. Straight chlorine can bleach within a day.

Read this post and read the two articles that are linked to:

Not All Color Pigments are Good for Pools

There are two important issues involved when trying to achieve quality colored pool plaster that will remain durable, attractive, and the proper shade for many years. The first issue is to utilize superior workmanship practices to achieve good color, with minimal mottling, and no blotchiness...

www.troublefreepool.com

Yes, you will probably get a lot of denial and argument. As to your pool, IF it is indeed a bleaching issue, the other side knows that it would take effort, time, and money to prove that your plaster has been bleached. But bleaching of non-colorfast pigments in plaster has been proven.
Sorry about this situation that you are in, but I am just explaining what I know to be true. You are in a difficult situation.
The one thing that helps in your discussion with the plaster guy is that it appears (from your photos and discriptions) that the acid did not bleach the blue pigment.

 

[xtexan86]

The ppm amount of dissolved chlorine is relatively low. It is just reality that it takes many days and weeks to bleach colored plaster that contains non colorfast pigments. Straight chlorine can bleach within a day.

Read this post and read the two articles that are linked to:

Not All Color Pigments are Good for Pools

There are two important issues involved when trying to achieve quality colored pool plaster that will remain durable, attractive, and the proper shade for many years. The first issue is to utilize superior workmanship practices to achieve good color, with minimal mottling, and no blotchiness...

www.troublefreepool.com

Yes, you will probably get a lot of denial and argument. As to your pool, IF it is indeed a bleaching issue, the other side knows that it would take effort, time, and money to prove that your plaster has been bleached. But bleaching of non-colorfast pigments in plaster has been proven.
Sorry about this situation that you are in, but I am just explaining what I know to be true. You are in a difficult situation.
The one thing that helps in your discussion with the plaster guy is that it appears (from your photos and discriptions) that the acid did not bleach the blue pigment.

Yes, I did find that article and sent the plaster guy an excerpt from it. I also asked if he knew what kind of color pigment is used in Diamond Brite. I also found another comment on SGM's (maker of Diamond Brite) website that says if hard water is used in the mixing of the plaster, it "will cause the plaster to effloresce, releasing high levels of salts that produce calcium scale." Now, is this saying this process will occur continuously or, if not, does the calcium initially leach out the blue pigment? Our municipality has hard water so looking at different possibilities. Still find it odd about the timing of the acid spill and the plaster color change so shortly afterwards (1 + 1 = 2) and that makes it very difficult for me to deny the acid had anything to do with the pigment loss. One thing is certain, if after power sanding and proof of water chemistry stability from that point on, if the plaster loses it's color again within 2 months, I'm definitely suing or demanding replastering on their nickel.

 

[YippeeSkippy]

I also found another comment on SGM's (maker of Diamond Brite) website that says if hard water is used in the mixing of the plaster, it "will cause the plaster to effloresce, releasing high levels of salts that produce calcium scale." Now, is this saying this process will occur continuously or, if not, does the calcium initially leach out the blue pigment?

Wow. Just wow.

 

[sktn77a]

Ok, I hear you but this info puts me in the dreaded position of "he-says, they-say."

Unfortunately, you're probably in this situation because you haven't been doing the pool "maintenance" yourself. Get a test kit and find out what the chlorine, pH, TA, CH is. Without this information, nobody can offer any help at all.

 

[xtexan86]

Unfortunately, you're probably in this situation because you haven't been doing the pool "maintenance" yourself. Get a test kit and find out what the chlorine, pH, TA, CH is. Without this information, nobody can offer any help at all.

Ok, one last time. I was not and still am not in a position to put "learning about pool maintenance" on my plate. I will try to get a water sample over to Leslie's for an analysis as soon as l can and post the results. But how dare you insinuate I'm at fault because I thought it'd be best to let a technician handle maintenance?? Are you someone who knows how to do everything around your house yourself....plumbing, electrical, gas, roofing, pest control, pouring concrete, trimming trees, foundation repair, etc., and has that much free time to learn how everything is done?? So if you ever do have to hire someone and they screw up, you're just going to blame yourself, right?? SMFH.