Question about stainless stanchions

[ebb]

Well respected rigging shop/yard/chandlery, and survivor of the take over wars in my area, makes custom stanchions. Might be interested in the 30" which are not generally available. They use too thin tubing and have to sleeve the stanchions for strength.

Everything I"ve heard about stainless says: to keep it from breaking down and rusting around salt the surfaces have to be exposed to generate a protective oxidised surface. For instance, whenever there's a chainplate bolted to a hull rust stains leak from behind. Stanchions inserted in bases develop rust.

Sleeving for strength doesn't sound like good stainless steel practice. Right?

I agree that 304 has no place on a saltwater boat. But tell that to the marine suppliers. Is there any way to be sure that the s.s. you're looking at is 316 or better?

As I read another thread here someone suggested epoxy paint over stainless and was not challenged by anybody. Jumping to conclusions maybe, but painting stainless is the last thing you should do. I think. Right?

[Nels Tomlinson]

Mild steel will rust if left bright, and will rust at least as fast if you cover it. Painting, on the other hand, seems to exclude oxygen completely, and prevents rust completely.

Stainless won't stain unless it's covered, in which case it will weep rust and pit.

I'd think that any paint which would prevent rust on mild steel would prevent rust and pitting just as well on stainless. Of course, if you're going to paint, why not just use galvanised steel? It's cheaper, and less likely to work-harden, than most stainless alloys.

I've heard that many folks in the Northwest are using galvanised standing rigging, with a few coats of epoxy paint, and that it lasts far longer than stainless of the same size. I don't have any personal experience with it, but you'll find many who do on this Yahoo group: http://groups.yahoo.com/group/origamiboats/ .

[marshmat]

You can paint over stainless, just doesn't look as nice as good clean chromium. To check the grade of stainless, put a fridge magnet against it; the higher the grade, the less the magnet will stick.