Bruce in Bangkok wrote:


I wouldn't argue that 304 is the alloy of choice for marine use but I
have rails on a 40' boat that were built from 304 and 10 after years
of use there is no corrosion on them....

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

Stainless steel does well in relatively dry environments with access to
oxygen. Look at your home cutlery, for example.
Then go buy a stainless bowl and fill it half full of water.

See how long it takes to develop its first pin hole.
A matter of weeks or less, quite likely.

Brian W