Strange rust spot appeared on side, no metal around

[QingGuy]

So this strange rust spot appeared on the side of my pool, unlike the other rust spot I have on the opposite side of the pool where my landscapers dropped a piece of wire into my pool and didn't reterive it there's no metal around this one. I've brushed it several times but nothing.

Any ideas on what this is and how to get rid of it? I will be draining this fall and acid washing while empty so hopefully if I can't do anything with it now that will remove it.

I've attached pictures for review. Thanks!

 

[JoyfulNoise]

Clear it with vitamin C in a sock. If it reappears in the same spot then it could possibly be a thin spot where the rebar is too close to the surface.

 

[jblizzle]

I agree with Matt. I had some of those in my old plaster before I had it resurfaced.

 

[CountryBumkin]

once it is cleared up, you may want to get some of the two-part underwater-curing epoxy and stuff or smear a little over that spot. I think there is small hole or gap a that location where the water is getting to the rebar and it needs to be plugged.

 

[QingGuy]

Thanks for the input! So it's nothing to worry about other than I should seal it up? Is this something the plaster guys could do after they acid wash? Any rush to do it now or can I wait until end of season? Also, is it a plaster or gunite issue?

 

[JoyfulNoise]

Thanks for the input! So it's nothing to worry about other than I should seal it up? Is this something the plaster guys could do after they acid wash? Any rush to do it now or can I wait until end of season? Also, is it a plaster or gunite issue?

The plaster would have to be chipped out in the area where the rebar is as well as some of the gunite shell. The rebar piece would have to be cut back and then the area repaired. It's not a super difficult thing to do but it does take some work. I would also expect it to look like the area was patched....once the plaster is "patched" it never looks quite right. Once you confirm that the stain reappears, I would talk to the plaster people you are using for the acid wash, they may have other ideas....