Plaster Coloration-Any plaster expert in the house?

[newpoolguy]

Our pool is just under a year old. The plaster is a "medium Tahoe blue", meaning it is grey. Took some pics with an underwater camera today and had a couple of questions:
there's a lot of mottling of the color throughout the plaster. Is this hydration staining or just an artifact of the color they put into the plaster? We like it...it gives the pool bottom and sides some interesting textures throughout the day...but wondering if this is normal.
Second picture is the eggshell cracking appearance of the steepest wall at the deepend of the pool. This eggshell phenomenon is only apparent on this one long wall, and there's no crack, per se...if you run your hand over the plaster, its smooth...but it has this odd eggshell cracking pattern that I don't understand.
Anyone out there an expert on plaster issues?
Looking forward to anyone's thoughts....
Thanks.

 

[Guest]

Might be the pictures, but it appears that you have some copper sulfite damage in there (purple discoloration). Did you use a copper algaecide by any chance? Also looks like some hard water (scale) build up. What is your calcium hardness level at?

The checking/crazing is normal, and somewhat to be expected. Happens more often in hotter climates (was your pool plastered during hot weather?), but is a part of plaster.

Here's a cut from the National Plasterers Council guidelines: "Since plaster finishes are composed of natural materials which have certain inherent characteristics, a certain amount of shading or color variation is a natural occurrence which should not be construed as a defect. The shade and color variation may vary and fade over time. The plaster finishes may become streaked, blotchy, or have a mottled appearance. Crazing (check cracks and hairline cracks) may be noticeable and may be quite pronounced with pool finishes other than white plaster".

Bruce

 

[newpoolguy]

Thanks for the reply and information, Bruce.

No copper has been used - that purple tone is an artifact of scaling down the pictures to a size that will fit here on the board.
There's no hint of purple in the pool or at the tile line.

 

[frustratedpoolmom]

Using a photo host site like PHotobucket.com might work better for you for attaching pics. (Select the "large" size when uploading to their site.)