Stainless Steel Question

I have a sailboat that I sail in freshwater with plans to someday take the boat offshore into saltwater. I recently inspected the chainplates and discovered a few of them were corroded. Fortunately I know someone who knows someone who was willing to fabricate a new set of chainplates from 304 ss for FREE. I would have preferred 316 ss but like I said...these were FREE!

My question is what type of finish would be a good choice? Would it be adequate to simply polish these or would it be better to plate them? The chainplates are about 15" and 2" of the material extends above the deck. The deck seal consists of polysulfide with a ss trim plate on top of that.

Thanks!

Rick

 

seems I answered my own question. The evidence is high that 304 stainless is inappropriate for the marine environment.

 

304 vs 316

316 is prefered however there are a large number of 304SS parts manufactured for boats that work out ok. The best finish and one that many manufactures use is to have the parts electropolished. This process is basically reverse plating and works well because it forces the chrome in the SS to the surface. It's the chrome that makes SS corrosion resistant. Look in the phone book or goggle "electropolish", most major cities will have a source.

 

Dreamer,
Make sure you have a decent amount of relief all around the chainplate where it exits the deck, (perhaps 1/8" or so) a thicker strip of sealer will allow a little more flexing without peeling away from the metal, you might also want to test your intended sealer on a scrap piece of stainless to ensure it'll adhere well.

Yokebutt.