Rusty Skimmer Hardware after Removing Winter Cover

[butterblum]

I searched through 6 pages of search results and couldn't find exactly what I was looking for, so I am asking this in a dedicated thread:
I have owned my in-ground, vinyl pool for 4 seasons now (the pool itself is from ~1976), but this is the first time I have noticed this issue; when I removed my winter cover(s), there was quite a bit of rust around the opening of my skimmer (Pentair), as well as on the screws securing the faceplate to the wall; however, there was no rust on the screws holding the return flange to the wall on the other end of the pool. I do use 2 covers during winter to avoid water ingress (safety + tarp-style), which would also theoretically prevent the escape of any evaporation under the cover(s), possibly contributing to the problem.

From what I understand, the rust around the perimeter of the opening is actually from the wall of the pool itself, and the rust on the screws is due to chlorides corroding the low-grade stainless they are made from.
It appears that this may have been an issue before (there is some sort of white sealant around the opening and maybe even extending into the skimmer?), and it looks like the rust on the screws is actually originating from inside the philips slot, and not from the threads themselves.
My questions are as follows:

1. Are there any high-quality replacement screws available? They appear to have a unique thread pattern, and are not a UNC or UNF style. The skimmer is Pentair-brand.
2. Assuming I drop the water level to replace the stained faceplate and screws, is there any part of the replacement procedure that I need to be careful with? Is there a seal behind the faceplate? If so, is it in front of, or behind the vinyl liner?
3. Any way to remove any of the staining that has spread to the liner?
4. Do I need to worry about the rust on the metal wall? Can I just protect everything with a sealant to prevent the spread of the existing rust? What sealant is best? Does sealant get applied before, or after the installation of the faceplate?
5. Any chance that this is galvanic corrosion? Or is this pretty normal chemical corrosion?
6. Any reason to think that there was something unique about this year's winterization to cause this? Or is this just accumulated wear from years past?

Any advice is appreciated.
Thanks

 

[PoolStored]

I can't answer 1-6. I've had a bit of staining around the screws on my waterline. No staining, above or below. Some vitamin C tablets in a sock have corrected the staining. There may be others that will pipe in with longer term solutions. I have just accepted that he quality of SS has degraded and use Vit. C 2x per year and moved on....

I don't see the staining on the liner in your picture.

While I'm a Wolverine living in Ohio...O H I O. Yuck, that is just repulsive.

 

[Hoster]

I have a similar issue and not sure you were able to see this thread from last year. As for your questions, my two cents include:
1. Any stainless steel worked for me and as you indicated the issue WAS NOT from the screws
2. See my thread - but in short, you should have a gasket behind the plate, then a foam-like padding behind the liner - or at least that's what I had. Depends on who / how the gaskets were applied, your pool guy may used silicone so maybe time-consuming to remove. You may see "black stain/remaining" of gasket right behind the plate (if OEM Hayward gasket not those rubber ones)
3. not sure you can actually prevent the spreading - I use ascorbic acid to treat rust / rust stains (my issue is that I have to treat almost every week and it is getting expensive)
4. I have white plastic steps (pool entrance) and white light housing, and they turn "brown" so I know I have rust in the water. I don't remember exactly which sealant / silicone I used last season but marine-grade / waterproof one and I applied around screws and around gasket / skimmer - obviously this may not worked as I am experiencing rust stains yet again only after 5 days of opening the pool
5. Not sure about yours but I think mine is galvanic; I keep my Ph level rather consistent so....
6. As for me, I think my issue stemmed from simple aging...didn't experience rust stain first 5 years or so of owning this pool (2015 - ) but rather frequent last 3 years or so.

Good luck and keep us posted. Let me know if you have any questions.