SS or Silicon Bronze?

[bassman1956]

I'm looking at hardware for mounting the leeboard pivot blocks through the deck, and also for the side wings the boards rest on through the hull. Looking at Si bronze, I can get everything I need, but at a cost roughly 8 to 10 times that of 18-8 SS.

Maybe, for the wings, where the stove bolts wind up buried in construction, I should consider the Si bronze. Otherwise, I find it hard to justify the expense. The boat is a 24' trailer sailer, hauled out and stored mostly, that may or may not see estuaries and salt water.

What are your thoughts?

[RainDog]

I use almost all bronze on my boat, but if I was in your situation I would go stainless. For a pampered freshwater boat, it should last forever. My last boat was fresh water, 20 years old, and in the water year round. I never saw any signs of corrosion.

Wish I could say the same for my current boat.......

[skipmac]

I would go with the SS for the cost difference with two exceptions.

1. Any part that might be sealed in a wet environment and thus subject to crevice corrosion.

2. Any major load bearing part that is subject to repeated stress cycles or bending where it might work harden.

[Laidback]

Note 18-8 Stainless is no better than 304 -- If you need stainless to compare with Silicon Bronze then do so with 316 which will stand up to the elements.

[bassman1956]

Thanks all.

Noted, 18-8 is rather generic for all austenitic stainlesses of the 300 series. But yes, going with 316 for anything that replacement worried me would be cheap insurance.

The bolts that really worry me are the 3/8 x 6" carriage bolts that hold on the leeboard supports, just above the water line. They may get bumped, but I'm more worried about any dampness. Well sealed and epoxied, and a dry sailer, these issues should be minimal. But...

[motion30]

8-18 is 304ss

[delmarrey]

Lets hope it is a 304L, which has about 3 times less carbon and a bit more nickel to prevent corrosion. You'll know if to take a strong magnet to it.

[bassman1956]

Originally Posted by motion30

8-18 is 304ss

Except when it is one of the other 300 series that are 18%chromium and 8% nickel, like 301, 302, 303, and others.

Often, it's taken for granted to be 304. But that's not necessarily so. Still, point taken.