Keel assembly considerations . . . .

[Charles Brennan]

This is mostly for Spot, after a conversation on Chat Night.
We had talked about aligning the keel bolt in the hull.
Based on a suggestion from Kruse'n, I had printed out a "bullseye" onto a large format label and cut it out and placed it over the bolt-hole in my swing keel.

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The color and angle of the stripes tells you how close you are to alignment and (more importantly!) which angle you need to move the keel to align it.

Spot also mentioned that he was replacing all his hardware in kind.
When I pressed him, he allowed as how his bolts were type 304 stainless steel.
Wrong.

I get that holding the stuff in your hand, there appears to be very little difference:
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Everybody! Sing along: "One of these things is not like the other . . .  ."
Ok, actually two of them.  Bolt all the way at left is not marked and could be anything: 18-8, 304, whatever.
The two in the middle, are type 304 stainless steel.
At the far right and just about indistinguishable from the other two is a type 316 stainless steel 5/8"X11 6 inch long keel bolt.

Why the obsession, Charles?
Here's why:
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The bolt at top of pic is the original factory bolt from Laguna Yachts when they built my sailboat in 1976.
I replaced it in 1999, since it had gotten a little bent from hard groundings and whatnot.
At the bottom of the pic is the bolt I replaced it with. 
A type 304 stainless steel bolt, after 5 years usage.
When I checked the factory original, you guessed it: 316 SS.
I immediately ran right out and got a replacement 316 SS keel bolt.

Really hard to see any difference when they're new.
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But 5 years later . . . .
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And the ONLY reason I even found it, was because the keel tilted at an angle inside the trunk, and was hard to retract and I wanted to understand why.

Anyway, it made me into a Big Believer and I encourage people I run across to upgrade their hardware, so they never have a near heart-attack incident like I suffered, when that bolt came out of the keel.

Hope this helps, Charles Brennan

[Spot]

Thanks for the public service announcement CB!
My understanding is that the chlorides in seawater are harder on 304/18-8 than on 316.

[Riley Smith]

Yeah, that 316 bolt is STILL good. A couple of taps with a hammer in the right place and you'd never know it was bent. 304/308 isn't designed to deal with the corrosion factor of salt water. And look at the failure.....corrosion does horrible things to expensive bolt! On your KEEL!!! I used 316 in the catboat pin 25 years ago and it's no worse for the wear, although the centerboard isn't very heavy. The centerboard itself has two stainless plates inlet into it to ride on the pin.