Mottling on Replaster pool

Construction or upgrading of new or existing
swimming pools. Pool building materials and
miscellaneous construction techniques.
john007
Pool Newbie
Pool Newbie
Posts: 1
Joined: Thu 28 Jun, 2007 11:04

Mottling on Replaster pool

Postby john007 » Thu 28 Jun, 2007 11:13

A reading of the various websites and literature indicate a differences of opinion on causes of mottling and spot etching. My newly replastered pigmented (green) pool has a high degree of mottling. Mottling was evident right after fill up. The pool service company hired to plaster and startup the pool has oferred to do a mild acid wash. They believe it will take out the white.

I haven't seen any discussions on remedies for spot etching and or mottling. Short of replastering, Is a mild acid wash acceptable if it does take out the white for a satisfactory appearance? Will a mild acid wash reduce that expected life of the new plaster?. Will the mottling come back after some time?

Where can I find out more about the remedies for spot etching or mottling.


geeman
Swimming Pool Wizard
Swimming Pool Wizard
Posts: 76
Joined: Wed 18 Oct, 2006 14:12
Location: PA

Mottling on Replaster pool

Postby geeman » Thu 28 Jun, 2007 20:42

first of all you are talking about two absolutely, totally, 100% different things. etching is deterioration of plaster due to water chemistry. mottling is an inherint characteristic of ANY colored or even white plaster. it is not a defect. it is not caused by improper water chemistry. it is NORMAL and unavoidable. there is nothing wrong with your plaster. the only thing wrong is if your contractor failed to tell you that your pool would be mottled.
epaulette
Pool Newbie
Pool Newbie
Posts: 2
Joined: Thu 12 Oct, 2006 11:04

Mottling on Replaster pool

Postby epaulette » Fri 29 Jun, 2007 15:20

My 1 yesr old pool was just diagnosed as having mottling after 6 months of treachourous testing and no one could figure out what it was. To be honest I don't buy this Mottling thing. I have these terrible black stains on the walls and mostly in the deep end and the pool company is trying to wipe there hands clean by telling me that it is a chemical problem that caused the mottling. If you ask me it is a perfect excuse for pool builders to get out of problems by blaming the pool ownere!!
Guest

Mottling on Replaster pool

Postby Guest » Sun 01 Jul, 2007 20:14

pool surfaces do not just go wrong without some type of influence (water chemistry!)
Alvin

Mottling

Postby Alvin » Sun 04 Nov, 2007 09:31

Anonymous wrote:pool surfaces do not just go wrong without some type of influence (water chemistry!)

Your answer is incomplete. The discoloration in the plaster, especially in dark plaster, is due to a reaction between the water in the pool and it's chemicals, and the plaster.
However the latest research done by " On Balance" and by the NPC " National Plasterers Council" points in the direction of the paster mix and it's application.
Without going into great depth of chemical reaction of the various components of the plaster mix, temperature and humidity on the day of application, and manner of troweling, the bottom line is that the plaster is uneven in it's mix, and uneven in it's hardness. Therefore, when water and chlorine, and acid, or any other chemicals hit the plaster, they affect different spot in different ways. Ergo Mottling. If you read your plastering contract, you will see that there is a disclaimer regarding discoloration and , or Mottling.
Mottling is not regarded as a defect, but something that just does happen.
Mottling is also very different from staining. Mottling usually appears as small 1/2" round spots, or straight lines up to 1' long.
Stains in a pool are usually of random shape, and of different colors depending on the minral that is causing them.
Pool Professional

Re: Mottling

Postby Pool Professional » Sun 04 Nov, 2007 09:37

Alvin wrote:
Anonymous wrote:pool surfaces do not just go wrong without some type of influence (water chemistry!)

Your answer is incomplete. The discoloration in the plaster, especially in dark plaster, is due to a reaction between the water in the pool and it's chemicals, and the plaster.
However the latest research done by " On Balance" and by the NPC " National Plasterers Council" points in the direction of the plaster mix and it's application.
Without going into great depth of the chemical reaction of the various components of the plaster mix, temperature and humidity on the day of application, and manner of troweling, the bottom line is that the plaster is uneven in it's mix, and uneven in it's hardness/density. Therefore, when water, chlorine, acid, and/or any other chemicals hit the plaster, they affect different spot in different ways. Ergo Mottling. If you read your plasterers contract, you will see that there is a disclaimer regarding discoloration and, or Mottling.
Mottling is not regarded as a defect, but something that just does happen.
Mottling is also very different from staining. Mottling usually appears as small 1/2" round spots, or straight lines up to 1' long.
Stains in a pool are usually of random shape, and of different colors depending on the mineral that is causing them.
usfsg
Pool Newbie
Pool Newbie
Posts: 1
Joined: Wed 12 Dec, 2007 10:32

Re: Mottling

Postby usfsg » Wed 12 Dec, 2007 10:35

Alvin can you place a link showing where you found that information by the NPC and On Balance. I'm taking the people to court who redid my pool and that would be the second nail in the coffen.



Alvin wrote:
Anonymous wrote:pool surfaces do not just go wrong without some type of influence (water chemistry!)

Your answer is incomplete. The discoloration in the plaster, especially in dark plaster, is due to a reaction between the water in the pool and it's chemicals, and the plaster.
However the latest research done by " On Balance" and by the NPC " National Plasterers Council" points in the direction of the paster mix and it's application.
Without going into great depth of chemical reaction of the various components of the plaster mix, temperature and humidity on the day of application, and manner of troweling, the bottom line is that the plaster is uneven in it's mix, and uneven in it's hardness. Therefore, when water and chlorine, and acid, or any other chemicals hit the plaster, they affect different spot in different ways. Ergo Mottling. If you read your plastering contract, you will see that there is a disclaimer regarding discoloration and , or Mottling.
Mottling is not regarded as a defect, but something that just does happen.
Mottling is also very different from staining. Mottling usually appears as small 1/2" round spots, or straight lines up to 1' long.
Stains in a pool are usually of random shape, and of different colors depending on the minral that is causing them.

Return to “Building, Construction & Rebuilds”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 0 guests