Stainless steel parts not good for liveaboards

[tarponchik]

My BC is relatively cheap, about $250 Mares. It shows no signs of rust, though it survived this same trip on Belize Aggressor IV. But stainless steel is not invincible. Anyone who ran HPLC in the lab knows that though everything is made of 316 SS, all manufacturers warn against using buffers containing chloride, Cl-, and . Which, of course, is abundant in salt water.

Moderators, please delete this one!

 

[tarponchik]

WRT the topic I reckon in my non metallurgical opinion that you got a bad batch

Could it also be the wrong type of stainless? Stainless steel is not invincible to corrosion. As I recall, when I ran HPLC in the lab, everything was made of 316 steel but every manufacturer warned against using chloride-containing buffers. Which, of course, what sea salt is, sodium chloride.

I googled the subject briefly and found that stainless steels with 8-10% nickel content, the 304/304L and 316/316L types, are the most susceptible to chloride-induced corrosion, while high molibdenum contents in 904L type and alikes (255, 2205, "Alloy 20") make these types more resistant. Ferritic types like 430 and 444 are strongly resistant to chloride-induced corrosion (and BTW they are also highly magnetic). So, I am not surprised that @Wookie saw black nickel oxide in his corroded stainless steel samples.

Interestingly, in my own BCD which is a cheap Mares (~$250 new) about 10 years old, the metal parts show no signs of rust whatsoever, despite surviving the same Belize Aggressor IV trip.

 

[Hoag]

There is one question that is, as yet unanswered.

@Dogbowl, other than your unfortunate experience with some of your gear rusting, how was your first experience on a LOB?

 

[Dogbowl]

@Hoag, thanks for asking. Please stay tuned as I am gathering my thoughts and will write a trip report shortly!