Contractor lying abt acid wash?

[cmgg]

Paid to have plaster pool light acid washed since we had to drain it bc of replacing tile and coping. Results disappointing. I think they just power washed it. Company is standing by their tech, because the ticket says he was there for a few hours, way longer than it should have taken. See before (blue white diamond tile)and after (blue tile)pics.

 

[Casey]

Welcome to TFP cmgg!

Someone will be along shortly to help you with this acid wash.

 

[karmabiker]

Without knowing what is causing the gray in the plaster it is hard to say. You could test with a 50/50 MA/Water dilution in a small area. Scrub with a brush for 30 seconds then wash thoroughly with water. Keep it SMALL otherwise you are going to need to worry about neutralizing the puddle in the bottom of the pool.

I would do an area near the puddle in the bottom of the pool so you don't add any streaks. Before you start - measure the pH of the existing puddle, then again after. Make sure you are in range that the puddle won't damage the plaster (7.2-7.8)

... and take before and after pictures.

WEAR GLOVES A MASK AND GOGGLES. This is caustic stuff. Expect green foam and lots of nasty vapors.

 

[onBalance]

Certain types of graying does not come off with an acid wash. So I agree with KB that you should try that experiment (closely following the instructions) by using a small amount of acid on a gray area.

If the diluted acid solution doesn't remove the gray quickly, then the gray is internal to the plaster. In other words, it is not a deposit type of stain that is easily removed by acid or by sanding.