Insist on 316. 316L if any welding will be done on it. All stainless can
rust to some degree but 316 is far better at resisting it.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"pete" wrote in message
...
Hi, I need a forestay attatchment for my boat, someone has proposed
304 stainless steel instead of 316. As its a pretty important part of
my rig, I'm a bit dubious, but I don't know if its any more likely to
be corroded. A lot of it will be buried in the stem, but a lot of it
will also pop out above deck to take the forestay.

Any advice? I feel uneasy about 304.

Cheers, Pete

In the pulp and paper industry we used 316 2B finish 304 was out of the
question. All welds have to be pacified to minimized rusting. Contact or
welding with another metal like aluminums, steel or iron will produce white
intergranular corrosion that is hard for the human eyes to see. It is hard
to recognized 316 from 304 and many suppliers and manufacturers are selling
304 for 316.
As previously mentioned 316L is a good choice for welding.


"Glenn Ashmore" wrote in message
news:1t7rg.115845$Ce1.76526@dukeread01...
Insist on 316. 316L if any welding will be done on it. All stainless can
rust to some degree but 316 is far better at resisting it.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"pete" wrote in message
...
Hi, I need a forestay attatchment for my boat, someone has proposed
304 stainless steel instead of 316. As its a pretty important part of
my rig, I'm a bit dubious, but I don't know if its any more likely to
be corroded. A lot of it will be buried in the stem, but a lot of it
will also pop out above deck to take the forestay.

Any advice? I feel uneasy about 304.

Cheers, Pete

All welds have to be pacified to minimized rusting.

I think you mean, "passivated".

Thanks for correcting me. Yes, I mean "passivated" and inadvertently typed pacified.

Here is an extract: " According to ASTM A380, passivation is "the removal of exogenous iron or iron compounds from the surface of stainless steel by means of a chemical dissolution, most typically by a treatment with an acid solution that will remove the surface contamination, but will not significantly affect the stainless steel itself." In addition, it also describes passivation as "the chemical treatment of stainless steel with a mild oxidant, such as a nitric acid solution, for the purpose of enhancing the spontaneous formation of the protective passive film."

Also http://www.mmsonline.com/articles/100304.html

Over the years I have found out that most welding job done without proper cleaning, passivation and polishing started to show brown rust as early as the first year.


"Richard J Kinch" wrote in message . ..
All welds have to be pacified to minimized rusting.

I think you mean, "passivated".