New Plaster Startup NPC vs Bicarb vs Orenda

[dylanac]

Had my pool replastered last year with plain, white plaster and had significant issues with mottling and discoloration (see here). I followed NPC startup last time per PB recommendation. After a winter of back and forth, PB has agreed to redo the job, which is scheduled to begin at the end of this month. I have been extensively researching NPC vs Orenda vs Bicarb startups to hopefully avoid issues this time around. I would like to do bicarb startup, but I asked PB about Bicarb and Orenda startup and they do not support either method and they keep saying to follow NPC.
So what to do...

For reference, I just tested my fill water (city water from hose) and get the following:
FC=1.6, PH=7.0, TA=60, CH=100, CYA<30, TDS=200, TEMP=57 (likely will be higher at time of fill)
LSI=-1.26

LSI of fill water is obviously aggressive so at a minimum, seems like I should add Calcium Chloride to get CH =150 and Sodium Bicarbonate to get TA=100 (high end of NPC range). But even with these numbers I would barely have LSI=0. I am talking to someone at NPC to find out details on their recommendations. Just sent them my fill water numbers so waiting to hear back.

I see a lot of posts on bicarb and Orenda startups, but no long term follow up results. Does anyone have good (or bad) results they can report after a few years?
Should I ignore PB and do alternate startup method, which I assume would void my 1-year warranty?

 

[Bperry]

What are they doing to “redo” the job? Redoing the plaster would mean chipping out all the old plaster and reapplying new plaster. If they are just adding another cost of plaster over top of the old, you should reconsider letting them do it.

 

[dylanac]

What are they doing to “redo” the job? Redoing the plaster would mean chipping out all the old plaster and reapplying new plaster. If they are just adding another cost of plaster over top of the old, you should reconsider letting them do it.

They are chipping out old plaster and replacing with new.

 

[Bperry]

They are chipping out old plaster and replacing with new.

Are they going to do the same startup and application crew they did originally? Im wondering what theyll change to get a different result? Im really surprised they will chio out all the old plaster. Usually they just chip around the returns and tile line.

 

[dylanac]

Are they going to do the same startup and application crew they did originally? Im wondering what theyll change to get a different result?

I am doing the startup, which are my questions. For background, PB is a large company who does hundreds, if not thousands of plaster jobs a year, so I doubt I will have the same crew. As a homeowner and forum jockey not in the industry, I don't think it is realistic for me to micromanage the crew or their methods. I can ask questions, but I won't be standing next to the truck measuring the water.

Your comment implies you suspect the crew caused the issues, rather than improper chemistry. Seems like it has to be one or the other (maybe both?), but I have no way to prove or disprove that theory. Since they agreed to redo the job, I assume they have an interest in making sure their crew does a good job, since they want a happy customer, otherwise they would have refused.

I CAN control the chemistry once the hose is turned on, which is my original question. Looking for insight into the best startup for this situation, given the PB is only onboard with NPC. thx

 

[Bperry]

I am doing the startup, which are my questions. For background, PB is a large company who does hundreds, if not thousands of plaster jobs a year, so I doubt I will have the same crew. As a homeowner and forum jockey not in the industry, I don't think it is realistic for me to micromanage the crew or their methods. I can ask questions, but I won't be standing next to the truck measuring the water.

Your comment implies you suspect the crew caused the issues, rather than improper chemistry. Seems like it has to be one or the other (maybe both?), but I have no way to prove or disprove that theory. Since they agreed to redo the job, I assume they have an interest in making sure their crew does a good job, since they want a happy customer, otherwise they would have refused.

I CAN control the chemistry once the hose is turned on, which is my original question. Looking for insight into the best startup for this situation, given the PB is only onboard with NPC. thx

Got any pictures of what’s wrong? Do you have any test results data over the past year from a TFP Recommended test kit?

 

[dylanac]

Got any pictures of what’s wrong? Do you have any test results data over the past year from a TFP Recommended test kit?

Sure do. Click the link above in the first post. That thread has pics and data.

 

[Bperry]

Sure do. Click the link above in the first post. That thread has pics and data.

Ah, didnt see that link until now and i remember the original post now.

Doesnt sound like the startup or the water chemistry was an issue. If I was betting itd be that rhe application was flawed (too much calcium chloride or over troweling) like mentioned earlier.

 

[dylanac]

Ah, didnt see that link until now and i remember the original post now.

Doesnt sound like the startup or the water chemistry was an issue. If I was betting itd be that rhe application was flawed (too much calcium chloride or over troweling) like mentioned earlier.

That was the conclusion of onBalance. But there seems to be a conflict here. On one hand, the conclusion was that the installer was to blame for poor technique and the startup chemistry could not have caused the issues. But on the other hand, I read discussions from onBalance and Orenda that say the NPC startup (which I followed) is flawed, and you need to have fill water with CSI/LSI over 0.3 to protect the finish, which I did not do. Seems like both things can't be true.

 

[Bperry]

That was the conclusion of onBalance. But there seems to be a conflict here. On one hand, the conclusion was that the installer was to blame for poor technique and the startup chemistry could not have caused the issues. But on the other hand, I read discussions from onBalance and Orenda that say the NPC startup (which I followed) is flawed, and you need to have fill water with CSI/LSI over 0.3 to protect the finish, which I did not do. Seems like both things can't be true.

If you have a link to that discussion itd be a good read but usually the +CSI thing during startup is to make sure calcium isnt leached from the finish while its curing. Doesn’t seem to be gray mottling issue but thats way over my head now. Wish I could be more helpful.

 

[onBalance]

dylanac, I would agree that it "seems like both things can't be true" (both things being that bad plastering and a bad startup can't occur together. I understand that.
However, two questions should be asked that would help explain why both things can be true at the same time. The first question is; What does a flawed startup cause to the plaster? The answer is; a bad startup with very aggressive (or soft) water etches the plaster surface making it rough and porous. Aggressive water causes an etched plaster surface and will leave it white or the original color, but cause long term discoloration problems.

The other question is; what does bad plastering cause. In this case with your pool, it is likely that too much calcium chloride was added to the plaster mix and late excessive hard troweling was performed. Those two errors cause a darkening and mottling the plaster surface and turning it grayish. I posted a write up about that topic here on TFP. The two different issues and outcome are exclusive to each other.

I am glad to hear that the contractor has agreed to re-plaster your pool. I also hope that you will consider doing a Bicarb startup that has a 30 year track-record of success. I hope things turn out better this next time.

You might be interested in this article.

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

 

[onBalance]

I should add that your plaster may have some signs of etching because of the aggressive tap water. It would be a slight roughness to the feel. However, since the water was aggressive only for a short period of time, I don't know how much etching occurred. It may not be noticeable by sight or even feel. Probably only under magnification would show the damage done by short-term aggressive water.

Another thing to mention is although a bad aggressive water startup does not cause graying, it is also true that a good proper startup would not prevent the graying of the plaster color.

 

[onBalance]

Did you recall seeing some plaster dust last year when your pool was plastered and filled with water?

 

[dylanac]

Did you recall seeing some plaster dust last year when your pool was plastered and filled with water?

Thanks for that info, it certainly makes more sense now. I think there was some etching in spots, so what you said makes sense. Bad plaster job and initially aggressive water combined here to produce bad results.

I have read the article you linked. It all makes sense, but I feel it's going to be difficult to police the crew to that level of detail, but I plan to bring up some of the main points with the project supervisor. But I wouldn't be surprised if he humors me and the work crew (likely not english speaking) will just do it the same way they always do. I did get the PB to agree to delay starting to fill the pool for 6 hours. It took 18 hours to fill last time, so I still make the NPC 24 hour rule. Last time they started the fill immediately.

There was not much plaster dust last time. I could see a little bit during the first few days, but only when brushing. The water was never cloudy and my cartridge filter didn't require cleaning.

Regardless of the startup method, it seems that 7.0 PH is too low. How would you deal with this problem? Sodium Bicarbonate will raise it slightly, but not much.

 

[Bperry]

Thanks for that info, it certainly makes more sense now. I think there was some etching in spots, so what you said makes sense. Bad plaster job and initially aggressive water combined here to produce bad results.

I have read the article you linked. It all makes sense, but I feel it's going to be difficult to police the crew to that level of detail, but I plan to bring up some of the main points with the project supervisor. But I wouldn't be surprised if he humors me and the work crew (likely not english speaking) will just do it the same way they always do. I did get the PB to agree to delay starting to fill the pool for 6 hours. It took 18 hours to fill last time, so I still make the NPC 24 hour rule. Last time they started the fill immediately.

There was not much plaster dust last time. I could see a little bit during the first few days, but only when brushing. The water was never cloudy and my cartridge filter didn't require cleaning.

Regardless of the startup method, it seems that 7.0 PH is too low. How would you deal with this problem? Sodium Bicarbonate will raise it slightly, but not much.

They really started filling right away? My guys went home for the night. Then came back next day for an acid wash and then started filling.

 

[onBalance]

For plastering, the most important thing is to try and limit the amount of calcium chloride (hardening accelerator) added to the mix. One percent maximum to the weight of cement (sand aggregate not included).

Adding sodium bicarbonate to raise the alkalinity above 150 ppm would raise the pH high enough to protect the plaster. It would be safer to suggest adding only bicarb and not something else that could cause the pH to go too high and scale the pool. After the pool is full of water, make sure the pH is below 8.0 and then immediately add some calcium (hardness increase) to raise the hardness level.

I think your plastering contractor knows what caused the discoloration. And he know that adding tap water with such a low pH, alkalinity, and calcium hardness is just wrong. It is far too late to balance the water to the NPC standards after the pool has been filled with that aggressive water.
As you learned on the first go-around, the pH went very high, and both the alkalinity and calcium level went up. That means the plaster forfeited (etched) material from the surface before it even got full. You might want to share that info with the contractor.