No real answers to the mottling but then is it a pre mixed Plaster or plain Marble mixed on site .
The dodgy cement sounds a main suspect then what else is added by the mixer. It could be a bonding agent I use a Polymer from Vinapass (Wacker) it makes a world of difference.
So what ever is causing the problem one needs to know all the facts.
. Sounds like a hydration problem. I won't go into the long explanation about the cement matrix but check where your white cement come from. The Columbians have been flooding Florida with inferior cement. Cement production requires very very high heat. If your heat source is old tires, you cannot get high enough temperature. Anyway...make sure you're using top notch white cement or you're going to have hydration problems that will "gray out" your plaster job. No, I don't sell cement. I make dose pack color for pool plaster. Good luck!
we are now experiencing mottling -graying of the plaster- in several pools we have done this past summer and spring. and several companies who have used other companies to plaster their pools are experiencing an abnormal amount of very dark almost complete gray pools. In feburary I decided to use Fritz Pak non chloride acelarator instead of calcium to speed up the hydration in cooler weather. I have had 4 pools develop mottling even using the FritzPac, which leads me to believe it is the white cement. Our cement is bagged in south florida so i am wondering if anyone else in the southeast is experiencing a mottling problem?
I believe that the mottling discoloration is independent of the salt system, and would have occurred regardless of sanitizer. Check back with me and I will get you some cement and concrete references, or check some of the info on poolhelp.com under onbalance.
The Mottling that is happening from my studies (I manufacture a Pool Plaster that is different 100% Quartz no Oxide as coloring the quartz is ceramicly coated and the cement is added on site www.poolquartz.co.nz)
So the factors that can cause the mottling can be due to the bagged products cement having hydrated.
With regards to salt its been used in Australia and New Zealand since the 80s we down under I think invented it, most pool builders suggest you add the salt after a month or so opinions are varied. I have added it in the first week however the polymers added to our Quartz can plate out on the cells so I recomend about a wait of 6-8 weeks.
To sum up the mottling is a problem here with different plasters and is from what I have seen is due to the pre-mixed plasters being past there use by dates, oxides and cement that has hydrated.
How soon are you seeing this after new plaster? While I am not a fan of salt pools, we do see a lot of them. I don't ever recommend adding salt until new plaster has had a 60 day cure out.
Do you have any pictures of what you are seeing, and can you provide water chemistry levels? You definitely have my interest!
Thanks Doublas, for the input. Maybe "mottling" isn't the correct word. I say mottling because all that I've read, that's what it is, but the issue at hand is a "greying" of pool plaster that is only a few months old.
Mottling discoloration is integral to the plaster, and is not created by external chemical condiitons. If salt is added improperly to the swimming pool, without predissolving, and coagulates on the surface of the plaster, it can certainly etch the area it is oontact with over time. The etching process, however, does not create mottling. If you have both mottling and etching, which would be characterized by a uniform roughening of the surface and damage to aggregates, you have two different phenomena going on. And, in the event that salt was allowed to remain on the plaster surface, that specific area would show uniform evidence of that etching attack in that area.
A certain amount of mottling should be an expected characteristic of swimming pool plaster; however, excessive or extreme cases of mottling indicate that poor installation workmanship or material issues are involved. And,despite plaster advocates claims, "aggressive" water conditions do not cause mottling. Logically, if that were the case, would the industry ever acid started a freshly plastered pool-much less routinely perform acid washes and acid treatments?
Comments
No real answers to the mottling but then is it a pre mixed Plaster or plain Marble mixed on site .
The dodgy cement sounds a main suspect then what else is added by the mixer. It could be a bonding agent I use a Polymer from Vinapass (Wacker) it makes a world of difference.
So what ever is causing the problem one needs to know all the facts.
Norman kiwipool@vodafone.net.nz www.poolquartz.co.nz
I agree with douglas latta and suzanne leonard.
we are now experiencing mottling -graying of the plaster- in several pools we have done this past summer and spring. and several companies who have used other companies to plaster their pools are experiencing an abnormal amount of very dark almost complete gray pools. In feburary I decided to use Fritz Pak non chloride acelarator instead of calcium to speed up the hydration in cooler weather. I have had 4 pools develop mottling even using the FritzPac, which leads me to believe it is the white cement. Our cement is bagged in south florida so i am wondering if anyone else in the southeast is experiencing a mottling problem?
Brian,
I believe that the mottling discoloration is independent of the salt system, and would have occurred regardless of sanitizer. Check back with me and I will get you some cement and concrete references, or check some of the info on poolhelp.com under onbalance.
Doug
The Mottling that is happening from my studies (I manufacture a Pool Plaster that is different 100% Quartz no Oxide as coloring the quartz is ceramicly coated and the cement is added on site www.poolquartz.co.nz)
So the factors that can cause the mottling can be due to the bagged products cement having hydrated.
With regards to salt its been used in Australia and New Zealand since the 80s we down under I think invented it, most pool builders suggest you add the salt after a month or so opinions are varied. I have added it in the first week however the polymers added to our Quartz can plate out on the cells so I recomend about a wait of 6-8 weeks.
To sum up the mottling is a problem here with different plasters and is from what I have seen is due to the pre-mixed plasters being past there use by dates, oxides and cement that has hydrated.
How soon are you seeing this after new plaster? While I am not a fan of salt pools, we do see a lot of them. I don't ever recommend adding salt until new plaster has had a 60 day cure out.
Do you have any pictures of what you are seeing, and can you provide water chemistry levels? You definitely have my interest!
-Bruce
My question is; how often does the "graying" occur in Salt pools? Everytime? Often? Sometimes?
I don't maintain Salt pools, so I can't provide input on this question.
Thanks Doublas, for the input. Maybe "mottling" isn't the correct word. I say mottling because all that I've read, that's what it is, but the issue at hand is a "greying" of pool plaster that is only a few months old.
Salt system still applies.
Mottling discoloration is integral to the plaster, and is not created by external chemical condiitons. If salt is added improperly to the swimming pool, without predissolving, and coagulates on the surface of the plaster, it can certainly etch the area it is oontact with over time. The etching process, however, does not create mottling. If you have both mottling and etching, which would be characterized by a uniform roughening of the surface and damage to aggregates, you have two different phenomena going on. And, in the event that salt was allowed to remain on the plaster surface, that specific area would show uniform evidence of that etching attack in that area.
A certain amount of mottling should be an expected characteristic of swimming pool plaster; however, excessive or extreme cases of mottling indicate that poor installation workmanship or material issues are involved. And,despite plaster advocates claims, "aggressive" water conditions do not cause mottling. Logically, if that were the case, would the industry ever acid started a freshly plastered pool-much less routinely perform acid washes and acid treatments?