[CLOSECALL]

Hope I can get some help here. I need to replace the attachment on my Pearson's swing keel. The old one has corroded to almost nothing. It may be nearly 50 years old. It looks like it is probably some kind of bronze. It's only about 1/8 inch thick at best and in some places is almost paper thin. The board weighs maybe 200 lbs.

I can get 220 bronze sheet cut to size and would only have to drill a couple of holes to make the replacement. Or I can get aluminum bronze in 1/4 inch bar stock that could work and I think is more corrosion resistant than the 220 in seawater.

If any of you guys can tell me which way to go, I will really appreciate it so I can get this repair done and get this boat back in the water.

I've tried to get some info from a thread in the Pearson forum, but maybe here will get more exposure.

 

[Faster]

Any chance of a picture or a drawing? not quite seeing what exactly you're needing to replace (but confess lack of familiarity with that boat/system)..

 

[CLOSECALL]

How's this. This is not mine, but just like it (except this one is in good shape).

 

[Delta-T]

I would go with 316 stainless, and bolts, the cable should be 316 SS and the swage should be zinc coated copper. At least that is what lasted 25+ years before I changed it out for new last year. My details can be found here

 

[SloopJonB]

I'd use the most corrosion resistant bronze flat bar I could get. I prefer bronze to S/S underwater if I have the choice.

Frankly though, I don't think it much matters - I'm sure many boats have had fittings like that made from galvanized iron or steel.

 

[Faster]

Thanks Closecall.. that should be easy to fabricate once you choose your material!

 

[RichH]

Try drmarine.com for a replacement. Ask for Rudy.

You'll need VIN, year and model.

 

[Delta-T]

I'd use the most corrosion resistant bronze flat bar I could get. I prefer bronze to S/S underwater if I have the choice.

Frankly though, I don't think it much matters - I'm sure many boats have had fittings like that made from galvanized iron or steel.

The cable is SS and if in contact with brass in salt water, the SS will win out as you can clearly see in my thread.

 

[Delta-T]

Try drmarine.com for a replacement. Ask for Rudy.

You'll need VIN, year and model.

The problem here is abrasion in the cable tube. Why change something that is proven to work.

Edit: My bad, I thought you were suggesting Dyneema. I miss read that.

 

[CLOSECALL]

I believe I'll go with stainless. The rest of the system is stainless so that makes sense. Also stainless is more readily available. Thanks for the input.

 

[celenoglu]

"I need to replace the attachment on my Pearson's swing keel. The old one has corroded to almost nothing. It may be nearly 50 years old. It looks like it is probably some kind of bronze. It's only about 1/8 inch thick at best and in some places is almost paper thin. The board weighs maybe 200 lbs.I need to replace the attachment on my Pearson's swing keel. The old one has corroded to almost nothing. It may be nearly 50 years old. It looks like it is probably some kind of bronze. It's only about 1/8 inch thick at best and in some places is almost paper thin. The board weighs maybe 200 lbs."

Why change to another metal? Fifty years of use and although "corroded to almost nothing", my selection will be bronze again.

 

[CLOSECALL]

It "may" be 50 years old; it may be 10. It is "probably" some kind of bronze. I just don't know. There are different kinds of bronze and once again, I don't know what was used.

I'm 64 years old. If I can get the twenty five years that Delta got, I will consider it good.

 

[hellosailor]

I'd also vote for bronze. And get rid of the stainless steel cable while you're at it. In this century, synthetic cordage is the material of choice.

"This ain't your grandpa's nylon line."

 

[CLOSECALL]

I've been reading of amsteel having abrasion issues when used as lifelines. That is what steers me away from the new cordage.

Specifically, what type of bronze?

 

[seaner97]

That looks like a P35 centerboard. Mine (and all the other ones I've seen) are in stainless. I'd replace in kind, and it will outlive you, most likely. Figure on doing it again in 30 years if you maintain properly. The problem with amsteel or the like is the tube the pendant rides in will most likely have some sharp edges that will eat the "soft" lines alive and you'll be back sooner.
Ps- I just looked at the P35 message board and don't see this as a recent post. (Ahh- it's a 30, that's why!)
Edit: on a 66 30' the centerboard was very similar and same material was used.

 

[UNCIVILIZED]

If you go with Bronze, Aluminum-Bronze is supposedly pretty good. A well regarded foundry (which does a LOT of stuff for boats) was steering me in that direction when I asked about having a custom made P-bracket made for a Carbon Fiber boat. CF being pretty much at the top of the scale nobility wise, & thus especially tough on any underwater metals attached to it.

That said, you might look into Monel, especially Monel K-500. The latter having great corrosion resistance, like the former, but with the added bonus of strength which edges out a fair number of stainless alloys.

And of course, there's the old standby, Aquamet (AKA Nitronic-50). It's what quality "Stainless" prop shafts are made out of, as well as Rod Rigging.

If you want to look up the physical properties of any of these metals, or any other material, go to Online Materials Information Resource - MatWeb And said site also tends to list the distributors of any material in question, which you might look up.