New ladder Rust

[andrewjstrominger]

I had some iron staining in my pool the last few years. We got a new liner this year, so with the fresh water I wanted to get a new ladder in case the iron was coming from the previous ladder rust.

I ordered this SR Smith marine grade ladder: https://lesliespool.com/306340.html

The new ladder is already rusting after being in the water for four days. Is this expected? Water chemistry is good:

Chlorine: 4ppm
pH: 7.7
TA: 90
CYA: 40

In ground 25k gallons using liquid chlorine.

 

[ajw22]

What does SR Smith say about it?

Even marine grade stuff rust. Just slower.

 

[andrewjstrominger]

I emailed them but just noticed it today so I don't expect a reply until Monday at the earliest.

I definitely understand that it will rust but this seems like it’s happening way faster than I would expect.

 

[nuttyp]

Are those pictures of the new one? If so, gads. I thought stainless 304 is only supposed to be mildly affected let alone 316 or 316L. Any chance the bolts/nuts/washers are wrong or otherwise contributing?

 

[andrewjstrominger]

@nuttyp Yes, these are pictures of the new marine grade 316L ladder. That's why I was so surprised too. I figure it would happen...but no that fast. I put the ladder in the pool on Wednesday 6/19 and these pictures are from Saturday 6/22. I'm interested to see what SR Smith says. These are the bolts/nuts/washer that came with the ladder so I would think that they would be the same material too.

 

[nuttyp]

Interesting. That Leslies item cites both 304 & 316L. First it made me wonder which parts are 304 and which ones are 316L. As I glanced around the web to learn more about 316L, I think there was an implication that the metal's properties can change due to heat, but I think it was very high heat for a prolonged period. Still, it made me think about your pictures which seem to show most vulnerability in areas where they either cut the ends or drilled holes or welded (or the bolts). Not sure what that might mean, perhaps there are layers of metallic properties and they become exposed at a cut edge. Or overheated to make a bend? Just thoughts, it will be interesting indeed to learn what SR Smith says. I guess Leslie's might offer insight too, unlikely as that may seem. Pending any insights from vendors, I suppose you could swap one of the bolts for a known grade and reinsert as a test.