Large Stain on brand new plaster from Calcium addition

You are a pretty good chemist. Highly unlikely a copper issue.
Unfortunately, it looks like the PC is making the problem worse with those acidic spot treatments.
Yes, the small amount calcium simple goes into solution and is not a problem.

In re-reading your original posts, it looks like the tap water that was used to fill your pool is rather soft. Low calcium. If so, I would think that soft water created a lot of plaster dust for the first few days. Again, if that is true, then the plaster dust may have hardened onto the plaster surface, making the overall plaster surface somewhat whiter in color than the original darker color. I know this doesn't help now, but that is exactly what a Bicarb start-up would prevent from happening.

If you also have other streaks running down the walls, then I don't see another option other than a drain and complete sanding. Wish there was an easier solution.
 
Yes, our water is soft. I think all the beer makers around here have to add minerals to harden the water a little to bit so they can make terrific NW microbrews.

Unfortunately things have gone from bad to worse. The Jack's Magic treatment is headed into its second day and and except for a some large blotches where the magic elixir was swept along the bottom, not a heck of a lot is happening. The PC is super frustrated; fearful of the cost and outcome of a full pool sanding.

Time for a home-brew.
 
Hello gtemkin,

I'm sorry to hear about your botched re-plaster job which I come across on many occasion, I am not all that shocked at the negligence however I am shocked that this has gone on for what looks like approximately 4 months now with no resolution. Leaving you with nothing but headaches and countless hours of wasted personal time I assume.

First of all I am in no way here to provide any legal advice, I am in the industry and quite familiar with negligence on behalf of Pool Builders and Contractors from personal experience in correcting such issues. It is my opinion that you are allowing this situation to get way out of hand when it is not necessary and it is my belief that you need go back to the root of this problem and end this once and for all.

After going through your post and trying to gather as much information as possible these are my findings, suggestions and solely my opinion. The problem is plain and simple a "negligent start-up technique" and you should have to look no further for a remedy period. Personally I do bicarb start-ups of some variation exclusively here in So. Cal. depending on the finish, temperature and fill water conditions. For the most part as Kim stated (if that's Kim) :oops: with the exception of the words "properly done" being added so to say "a properly done bicarb start-up" would have eliminated any plaster dust from forming and not be an issue, but judging from your information that wouldn't have happened anyway, since they continue to muddle around.

Adding 'any" white powder directly to anything but a white plaster finish is beyond a rookie mistake and you can find hundreds of links stating that this should never be done, personally I don't even do this on white plaster. This alone tells me that the start-up person (I refuse to use "Tech" in this instance) obviously did not know what they were doing PERIOD! And the contractor is only dragging out the problem and inevitably making it more difficult for them to fix it in the long run as the plaster cures.

From the pictures you provided I looked at the first pic and thought HOLY COW WTF, then I realized you had highlighted the area :lol:, then after looking at the second pic it appears to me that the calcium sat on the bottom of the pool which is why it is darker in the center due to the plaster not needing to leech from this spot since it was saturated with calcium. The ring around the outside where the calcium stopped although prominent looks more uniform with the rest of the pool as far as color and pattern goes at least from what I can see anyway perhaps I'm mistaken. I have seen French Gray pools get brushed without using a brush vac which leaves a spot just like you have only white in color from plaster dust settling on the bottom of the bowl.

Your problem could be corrected within a 24 hour turnaround (depending on fill water pressure). The contractor is more worried about their bottom line which in turn gets hurt anyway in the long run as the longer they wait the harder or more difficult the work is to repair the problem.

ACID WASHING is 100% out of the question, it's a NEW plaster job whether a "re-plaster or new construction" it's still NEW plaster and the home owner should not have to degrade the surface by doing an acid wash because the contractor is a douche bag. What needs to be done is the pool needs to be drained and polished, which in many cases results in a phenomenal looking plaster job since the surface is smoother than troweling alone now.

24 hour turnaround is accomplished as follows:
Get two or three "Trash Pumps" not submersible pumps make sure your water has been neutralized (for city legal purposes) and wherever you are dumping it can handle the massive volume headed it's way. The trash pump Home Depot shows in their rental literature can pump about 12k gallons per hour, with three pumps you could drain your pool in about 45 minutes for around $140. Polish (sand) the stain out first and then polish the entire pool and spa to a uniform color and when done fill it back up and do a modified bicarb start-up (filled pool non pretreated water version), plus 50 ppm borate added. I use perlite for filter media in D.E. and Quad D.E. filters, use whatever your comfortable with.

Make sure your bicarb and calcium are premixed and added through the skimmer, leave system running continuously until your water is stable as far as balancing goes, meaning there's no drastic pH changes any more.

Document everything you can recollect from how much or how little the start-up fool brushed the pool, to the chemical addition processes from day one in case you have to seek legal action. And from I have seen thus far the contractor doesn't have a leg to stand on, so don't give him one.

Long story short have them drain and polish it asap.

Good luck, :goodjob:
 
Thanks for the detailed explanation and the time you spent writing it. I agree with your assessment that my PC seems to be looking after himself, and if he's even aware of any potential detrimental effects of the acid stain treatments, he's weighting his own financial concerns higher.

During my last discussion with the PC when I brought up sanding, he said he'd discussed that with his plasterer, and that because the plaster he used has a marble content, sanding would give it a "granite appearance" which wouldn't look right. Previously, when I asked him for the manufacturer of the plaster mix he refused to provide it. I personally thought solid color plasters normally contained some amount of marble, yet I haven't heard his concern with sanding from anyone else. Is his concern real or is he looking out for his own bottom line?

By the way, I agree that dumping chemicals into a colored plaster pool was a rookie mistake, but I sure wish it was stated in more blazing lights on some sites including the manufacturers of such additives. Most that I've found have warnings to NEVER to pre-disolve, always broadcast, likely fearing that the exothermic reaction of Calcium Chloride and water would result in a direct safety hazard that exposes them to more legal risk than a troublesome stain on the bottom of a pool. They do mention sweeping any undissolved product from the bottom, but there is little emphasis on this requirement and it's generally stated very casually. This is a difficult situation that I can't presume is a slam dunk. That's why I haven't made a final payment and will likely need financial relief from the PC in addition to something that looks good with a shorter life.

Edit: Pool was acid washed and stain was eliminated. Discount was taken on cost of plaster; water and heating charges were reimbursed. I've added this update edit nearly 2 years after the acid wash and all seems well.
 
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Pool plaster is mainly made up of three things.

1. PORTLAND CEMENT
2. AGGREGATES
3. ADDITIVES

PORTLAND CEMENT
Portland cement is a gray or white powder that is the binder for all cement products such as concrete, mortar and specialty products such as pool plaster.

AGGREGATES
Aggregates are the solid materials that are mixed with the Portland cement to give the product strength and mass they include silica sand and crushed marble, granite and quartz.

ADDITIVES
Water! When water is added the Portland cement undergoes a chemical reaction and grows crystals that glue or cement the aggregates together.

All pool plaster is a mixture of white cement and marble aggregate with the colored variations having the pigment added.

They're not supposed to polish the thing out like a granite kitchen counter :lol: , you use like a 220 grit diamond polishing pad and a high speed water sander. They don't know what they're doing if they say you can't do it because it'll turn out with a granite like finish. The main thing you are doing is getting the stain out and then blending the rest of the pool with the repaired area.

French or dark greys and especially black plaster finishes look phenomenal if done correctly via this method. The problem is that some people tend to "sand" aggressively like they were removing paint rather than "polishing" the finish with a fine grit pad.
 
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