Stainless steel parts not good for liveaboards

[scubadada]

I don't have the best of habits. On my week or 10 day visits to Florida, I generally leave my BC in my mesh backpack until the end of the visit, and then rinse and dry it. My 13 year old Scubapro Knighthawk has not a speck of rust. I rinse my regulator, computers, and wetsuit every day.

The crew on the Red Sea Aggressor and on the Cocos Okeanos Aggressor would rinse off all the equipment in place at the end of each day.

 

[Akimbo]

Stainless steel alloys actually do corrode in order to work. Ideally the Chrome (alloy content not plating) creates a very thin film of non-corrosive Chromium Oxide that protects the iron; which is the majority of the alloy. Normally that thin layer will "self-heal" when scratched. Even the most expensive grades of stainless, like 316L, can show surface rust or even pitting. The problem occurs when the Chromium Oxide is scratched and/or is unable to repair itself (self-heal). Iron particles are the most common culprit.

Higher Nickel and Chrome content alloys are generally more "rust" resistant. Rust is corrosion of Iron or Iron Oxide. Stainless steel cutlery is magnetic because high Nickel-Chrome alloys are too soft to hold a decent cutting edge. However, if you take care of these knives they rarely show surface rust. The most common alloys found in dive gear are 302/304. They have high enough Nickel and Chrome to be pretty good and have very low magnetic signatures, but are significantly less expensive and a little easier to machine than 316. Optimum manufacturing methods include passivation (commonly called pickling) after all fabrication processes to dissolve surface Iron and form a uniform Chromium Oxide layer.

Back to your basic problem: There is a good chance you can use a non-metallic abrasive pad like many kitchen sponges have to remove surface rust. This will also remove some of the Chromium Oxide layer but it will usually regenerate on its own. A very common source for this kind of rusting is surface iron transferred during the manufacturing process (steel rollers, drills, punches, etc) and not pickled. There are several DIY passivation processes that you can do that doesn't attack webbing that may be sewn on the part.

I have seen very expensive 316L stainless steel electrical panels on offshore oil production platforms ruined because a welder working nearby sprayed steel sparks all over them with a grinder. The surface rust wasn't noticed until the pitting broke through.

 

[Dogbowl]

I didn’t want to post pics as I didn’t want to tarnish a company’s reputation before I sorted this out but if one did some digging of my previous threads, it’s obvious which company we're talking about. So here are the pics.

I find it kind of ironic that the bcds are made in the USA. Most likely the parts are from China.

These pics are of my bcd. My husband’s bcd is rusting in exactly the same place, but on both cam bands.

 

[Lorenzoid]

I didn’t want to post pics as I didn’t want to tarnish a company’s reputation ....

I see what you did there.

 

[Wookie]

I didn’t want to post pics as I didn’t want to tarnish a company’s reputation before I sorted this out but if one did some digging of my previous threads, it’s obvious which company we're talking about. So here are the pics.

View attachment 456376

View attachment 456377

I find it kind of ironic that the bcds are made in the USA. Mostly likely the parts are from China.

It's also ironic that both of my cam band straps are from the same place. I would agree with the poster above. One got a Monday dip in the plating tank, one got a Wednesday dip, and the chromium is refreshed on Thursdays.

I'm not here to bash Chinese manufacturing. My last boat had Monday welds and Wednesday welds. The inspector and I laughed about it.

 

[tomfcrist]

I'm not here to bash Chinese manufacturing. My last boat had Monday welds and Wednesday welds. The inspector and I laughed about it.

I refer to them as $15 an hour and $35 an hour welds.

 

[Schwob]

My Apeks Black Ice BCD has some very minor rust right where the wireform meets the sheetmetal camband buckle... ever since my first (and so far unfortunately only) LOB. It is right where one would expect rust as suring every tightening of the camband the wireform pivots in the holes in the buckle and scratches the edge... and the two might be a very slightly different kind of SS (as one was selected to make bendable, weldable wire from, and the other to make sheetmetal from), so maybe there is a small amount of galvanic action. My BP & W has only seen freshwater so far.
Anyway, I don't think the wire itself should rust like that... to me it looks like somebody, somewhere along the sourcing chain of that component bought raw material too cheap or with questionable provenance.
@Dogbowl :
I am curious what the manufacturer says after you send them the pics and story.

 

[rongoodman]

I've done the same thing on multiple liveaboard trips and never noticed such a problem with my Halcyon BPs. I would replace the cam bands before the next trip.

 

[Dogbowl]

Anyway, I don't think the wire itself should rust like that... to me it looks like somebody, somewhere along the sourcing chain of that component bought raw material too cheap or with questionable provenance.
@Dogbowl :
I am curious what the manufacturer says after you send them the pics and story.

I am currently considering whether I should go through the shop I bought this from or go directly to the manufacturer. I’m leaning towards going directly to the manufacturer.

Honestly, if a bcd can’t stand the rigours of a 7 night liveaboard in the Caribbean...

 

[KeithG]

I am currently considering whether I should go through the shop I bought this from or go directly to the manufacturer. I’m leaning towards going directly to the manufacturer.

Honestly, if a bcd can’t stand the rigours of a 7 night liveaboard in the Caribbean...

And this was not likely caused by a lack of rinsing. The LOB crew hose down the decks at least once every day. This includes a thorough soaking of all BCs hanging on the tanks.