trouble with plaster

[gneissgirl]

The redo of my plaster (mostly white plaster with very little blue quarts) is very uneven with a lot of places that almost look like bubbles. There are holes in the plaster and a place that looks like rake marks. In full sun it is hard to see, but with the light on at night it looks horrible
[I had the coping, tile and plaster replaced spring this year. The plaster was a third layer. Long story, but the pool had to be drained and the plaster delaminated and had to be redone. They were just going to add a 4th layer but I had them chip it out to concrete. Second pour was in July (Texas).]
I have 2 questions:
1 - Does anyone know what could have caused this warping/buckling/bubbling?
2 - I had read on this site that an acid startup was hard on plaster, and I didn't like how it worked the first time, so I asked them not to do it this time. When I hired someone to give me an opinion on the quality of the work he indicated that the plaster won't cure properly without an acid startup. Can someone direct me to some resources on this topic?
Thank you so much!
Sorry the pic is not super clear. Hard to get a good photo

 

[ajw22]

Sounds like you may have calcium nodules developing...

Calcium Nodules in pools

What are calcium nodules? In swimming pools and spas, they are small mounds, bumps, deposits, or “slag” piles of calcium carbonate which are formed from material that has been released from the plaster. The small calcium nodules are rough to the touch, hard, and generally gritty. Nodules may...

www.troublefreepool.com

Let's see what @onBalance says about an acid startup. Acid startup is not the only way to go.

Start-up Chemistry for Plaster Pools The effects of four different chemical startup procedures were studied.

• the “Acid” startup – where enough acid was added to lower the pH to 4.5 and alkalinity to zero - about 3 gals. of acid per 10,000 gallons of water
• the “pH-Neutral” startup – which equates to about one gallon of acid is added to about 10,000 gallons of water
• the “Traditional” startup - where the water is maintained with CSI balanced water; near zero or (0.0) CSI
• the "Bicarb" start-up - where the tap water is pre-treated with sodium bicarbonate to raise the TA to 300 ppm and the CSI is about +0.6 to +1.0

Start-up Chemistry for Plaster Pools

The effects of four different chemical startup procedures were studied. the “Acid” startup – where enough acid was added to lower the pH to 4.5 and alkalinity to zero - about 3 gals. of acid per 10,000 gallons of water the “pH-Neutral” startup – which equates to about one gallon of acid is...

www.troublefreepool.com

 

[gneissgirl]

Sounds like you may have calcium nodules developing...

Calcium Nodules in pools

What are calcium nodules? In swimming pools and spas, they are small mounds, bumps, deposits, or “slag” piles of calcium carbonate which are formed from material that has been released from the plaster. The small calcium nodules are rough to the touch, hard, and generally gritty. Nodules may...

www.troublefreepool.com

Let's see what @onBalance says about an acid startup. Acid startup is not the only way to go.

Start-up Chemistry for Plaster Pools The effects of four different chemical startup procedures were studied.

• the “Acid” startup – where enough acid was added to lower the pH to 4.5 and alkalinity to zero - about 3 gals. of acid per 10,000 gallons of water
• the “pH-Neutral” startup – which equates to about one gallon of acid is added to about 10,000 gallons of water
• the “Traditional” startup - where the water is maintained with CSI balanced water; near zero or (0.0) CSI
• the "Bicarb" start-up - where the tap water is pre-treated with sodium bicarbonate to raise the TA to 300 ppm and the CSI is about +0.6 to +1.0

Start-up Chemistry for Plaster Pools

The effects of four different chemical startup procedures were studied. the “Acid” startup – where enough acid was added to lower the pH to 4.5 and alkalinity to zero - about 3 gals. of acid per 10,000 gallons of water the “pH-Neutral” startup – which equates to about one gallon of acid is...

www.troublefreepool.com

thank you

 

[gneissgirl]

I do think some of it is nodules forming, because "bumps" keep appearing as time goes on. Some of it, however, was visible once the pool was filled with water. I think there may be a couple of different processes at play here. I appreciate the references.

 

[ajw22]

You will find other reading about plaster problems here...

Plaster Installation and Maintenance - Further Reading

www.troublefreepool.com

 

[onBalance]

An acid startup is not necessary to properly cure pool plaster, including quartz and pebble finishes. In fact, as you have read, acid treatments actually do a little bit of harm to the plaster surface.

It sounds like the buckling, bubbling, and bumps may be due to the new plaster not bonding to the surface (delamination) when plastering. But a couple of better photos to look at are needed to be sure.