Calcium Nodules after Replaster?

[lakeboater]

I have read a number of posts about calcium nodules and I would appreciate comments about the picture in this post....is the white bumpiness likely calcium nodules?
It is very obvious at night, and it is visible if you look for it on a sunny day. The replaster was done last May (2024). It was not a chip out. They used a bond coat, and they did a skim coat of plaster before the final plaster coat. The contractor told me he believed the skim coat was more important than the bond coat. I noticed roughness in this area very soon after completion. What I'm not sure of is if it progressed. ( I left for 5 months shortly after completion) I was inclined to think it was just a poorly finished area, but after seeing pics of calcium nodules, I began to wonder.

Thanks for looking and commenting.

 

[Jimrahbe]

LB,

Are you talking about the white dots in your pic or the not so smooth plaster if you zoom in??

If the white dots, it is hard to tell what they are.. The not so smooth plaster is not calcium nodules..

I have a replastered rent house pool that has several nodules.. They seem to get bigger and bigger over time and they look similar to volcanos..

A couple of years ago, I drained the pool and sanded them down.. After about 6 month they came back... I assumed they would, but it was worth the effort.. Everyone of them was on a 'hollow' place under the plaster.. You could tap around the nodule and hear it..

The only thing that will fix the problem is to do a full chip out and then replaster.

Thanks,

Jim R.

 

[lakeboater]

Thanks for the comments. I am talking about the rough areas. The reason I was concerned that it may be calcium is that the roughness has no pebble...it looks like white plaster w/o pebble.

 

[Jimrahbe]

LB,

My only experience with nodules is with my rent house pool..

Those nodules are about the size of a dime and will grow much bigger.. They erupt from the plaster like a volcano and stick up quarter inch to an inch or so.

They tend to be isolated and not closely situated to others, so not at all like your "white plaster without pebble"...

Let's see what @onBalance has to say...

Thanks,

Jim R.

 

[ajw22]

See the pictures in…

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

 

[lakeboater]

Thanks Allen. I saw that excellent write up and agree my condition doesn't look like those examples. I am just confused why it appears like white deposit w/o pebble.

 

[ajw22]

Thanks Allen. I saw that excellent write up and agree my condition doesn't look like those examples. I am just confused why it appears like white deposit w/o pebble.

Either the pebbles were never there or the cream plaster was not adequately removed to expose the pebbles.

White spotting and mottling is common. Especially with blue plaster.

White Spotting of New Plaster Pools

The problem of plaster spotting has been an ongoing puzzle and controversy in the swimming pool industry for over three decades. The generally round, smooth-yet-unsightly white soft spots in new plaster pools have long been a source of contention among pool plasterers, and pool chemical service...

www.troublefreepool.com

 

[onBalance]

I do not see anything that resembles calcium nodules. I do see very rough areas.
It appears that the plaster is blue in color, and if the rough areas are the same color as the rest of the pool, then it is not typical calcium "scaling" which would be white. If this problem is simply rough plaster, it should be rectified by the contractor.
I suggest contacting the contractor and have them inspect your pool. Imo, the best way to resolve that roughness is to power-sand the rough areas.