Forestay Cotter Pin Maintenance

[stormalong]

Originally Posted by theway

That sounds like a good idea. Just to make sure I understand, you’re suggesting bend the whole pin, both legs in the same direction?

#1 in the image attached...
Attachment 159547

Your illustration #1 would be dangerous. There would be a high probability of it backing out.

Illustration #2 is the minimum needed. As I posted earlier I bend the ends into loops rather than using tape. With the loop there are no snagging issues and yes salt water being held against stainless does promote rust/corrosion. They call it stain LESS, not stain FREE. Have you ever seen crevasse corrosion? More common in 304 stainless than 316. It rusts perpendicular to the surface and usually starts at high stress points such as clevis pin holes. Many a mast has been lost due to chainplate failure due to crevasse corrosion. Ask any experienced rigger about it.

Also, I never re-use a cotter (split) pin. They are cheap and the price of failure is too high.

[theway]

Ok, then does anyone know what strategy james247 is talking about in post #29? Pictures maybe?

“I put the blade of a screwdriver at the point where the pincome through the cotter pin hole and get a radius turn rather than a sharp bend of the split pin. This stops a pinch point on the split pin which can weaken it. I never use a split pin twice. They are so important and so cheap”

[stormalong]

Originally Posted by theway

Ok, then does anyone know what strategy james247 is talking about in post #29? Pictures maybe?

“I put the blade of a screwdriver at the point where the pincome through the cotter pin hole and get a radius turn rather than a sharp bend of the split pin. This stops a pinch point on the split pin which can weaken it. I never use a split pin twice. They are so important and so cheap”

I think what he is saying is that each side of the split pin is bent in an arc as opposed to making a Y shape. An arc does not have a tight bend that may crack.

His description of how he does this is a bit confusing. I grasp the longer side of the pin with a needle nose pliers and form a loop. Then the shorter end is exposed and repeat the process on that one.

[theway]

Originally Posted by stormalong

I think what he is saying is that each side of the split pin is bent in an arc as opposed to making a Y shape. An arc does not have a tight bend that may crack.

His description of how he does this is a bit confusing. I grasp the longer side of the pin with a needle nose pliers and form a loop. Then the shorter end is exposed and repeat the process on that one.

Got it thanks.

And thanks james247

I’ll probably go up and have another look this weekend, last time the clevis pin was still in place without any signs of slipping to starboard.

[Alan Mighty]

Selden recommends that cotter pins/split pins at least as long as 1.5 times the diameter of the clevis pin.

Selden Mast is a leading manufacturer of mast and rigging systems.

Selden further recommends that the legs of the cotter pin be split 20 degrees, keeping the legs straight (as you might if you slipped the blade of a screwdriver between the legs). Selden further notes that if a cotter pin is opened more than 20 degrees, it will be difficult to remove. And that a cotter pin should be re-used no more than 10 times.

[Alan Mighty]

Originally Posted by Alan Mighty

Selden recommends that cotter pins/split pins at least as long as 1.5 times the diameter of the clevis pin.

Selden further recommends that the legs of the cotter pin be split 20 degrees, keeping the legs straight (as you might if you slipped the blade of a screwdriver between the legs). Selden further notes that if a cotter pin is opened more than 20 degrees, it will be difficult to remove. And that a cotter pin should be re-used no more than 10 times.

Brion Toss, a noted rigger and author, concurs: 'Unless there is some overwhelming reason to do so, never open cotter pin legs more than aabout 10 degrees each, so they form a narrow "V." They're no less secure than ones that are open wider and they're much, much easier to install and remove.' The Complete Rigger's Apprentice, 2nd ed., 2016.