Stainless steel parts not good for liveaboards

[JohnnyC]

Advertising “marine grade stainless steel” is pretty meaningless. Similar to saying, “aircraft grade aluminum.” It’s essentially worthless without knowing the specifics of what you’re getting.

Chinese manufacturing is 1% production and 99% QC. China is great at producing excellent quality first and second run products, then it declines as somebody figures out you can sub materials, or run the molds longer, etc., all you’ve gotta do is pretend that notbing’s wrong, make extra profits, and move onto the next one when your factory in Shenzhen gets their contract dropped. The other alternative is a materials sub when they can’t get whatever is spec’d in the contract, and to save face and keep their contracts, they pull a swapsies and just don’t tell the purchaser.

I knew a guy who worked in a fab shop in an aviation and defense-related company, half stainless, half other stuff. Each half had their own tools, painted red and painted blue. It was a fireable offense to cross contaminate the other shop by bringing in a tool with the wrong color paint on it.

I’d be willing to bet the manufacturer got their materials swapped by the supplier without being told, then a little contamination and boom there’s rust.

 

[Saniflush]

Another liveaboard that I am acquainted with was doing some interior modifications. The Coast Guard made them rip out all of the aluminum that they had recently put in at considerable expense because of a lack of traceability of the aluminum.

As someone who deals in purchasing aluminum coil you are absolutely correct. If you are wanting anything other than 3000 series alloy of aluminum the Asian metal has serious quality control issues at their mills. They are getting better but mill/material certification are nowhere close to what they need to be for products that need traceability.

 

[scubafanatic]

I work with a lot of stainless.
Not all stainless of the supposed same grade is created equal.
When I was doing boat railings I used to get 304 7/8” and 1” OD tubing from a supplier in Alameda that sourced everything from US manufactures. Never had a problem especially after passivation. They got some 316 from China and it was worse than the 304.
They went back to the US 304 because the smelting recipe is documented and certified to be accurate. Not so in China, they have no accountability so you will never know for sure what other crap might be in the alloy. I bought some supposed stainless all-thread that was supposed to be decent stainless. It was halfway magnetic.
Just because something is magnetic doesn’t mean it’s chromed steel! Cheap crappy stainless can be magnetic also.
You can soak that junk in acid all you want and it will never passivate, it just get’s eaten up.
I have a feeling those parts on the BC were from China (of course they were, everythings made in China nowdays!).
You folks with those great screamin’ deal Chinese regs, check your second stage levers and other stainless parts, you never know.

I can't even conceive of buying/using a Chinese regulator !

 

[EireDiver606]

Stainless steel rusts. End of story.

 

[EireDiver606]

I'm sure we'll hear back from Dogbowl shortly on this, but from what I have seen in her posts, she doesn't buy shoddy/cheap gear. Still, it is common practice to leave BCDs attached to tanks for a week--and for that matter, for all manner of stainless steel marine/scuba hardware not to get rinsed for a week or much more--and it does NOT rust.

I went for a dive with my brand new halcyon Eclipse a few months ago, that afternoon I rinsed it in the shower due to being on holidays and the single tank cam band adapter was slightly rusted???

Please explain this.

Needless to say, I was pretty pissed off. Haven’t contacted halcyon.

 

[EireDiver606]

I have cam bands that lived on the back deck of a liveaboard for 15 years and got rinsed once a year, when we went on vacation. My rings never rusted, and still haven't.

I have cam bands that lived on the back deck of a liveaboard for 15 years and got rinsed once a year, when we went on vacation. My rings never rusted, and still haven't.

How?

 

[Diving Dubai]

Stainless steel rusts. End of story.

If that were the case, all my backplates, my D rings and a host of other hardware all exposed to salt water would all have corroded.

Since they haven't I'm inclined to believe you're wrong.

 

[Wookie]

How?

I owned the liveaboard.

 

[Wookie]

Stainless steel rusts. End of story.

Nope. While all metals oxidize to one extent or another, not all stainless steel "rusts", that is, oxidizes in the form of FeO. Sometimes, under the right conditions, stainless turns black as in Magnetite (Fe3O4). It all depends on the amount of electrolytes and oxygen available.

 

[EireDiver606]

@Wookie and all the others I’m not going to argue with you but the facts prove you wrong.How did my halcyon STA get a blotch of rust ?

I’m looking more for info than a full on argument by the way...