Leak through cockpit sole around rudder stock

[Jim Almendinger]

All --
Bought my first boat a year ago: a 1968 Pearson Coaster.  We sail out of Madeline Island on the south shore of Lake Superior.  I've been chasing down minor quirks and topside leaks while learning how to sail for the last year. 

One leak I just realized is around where the rudder stock comes up through the cockpit sole (or floor -- apologies if I get my terminology wrong).  I removed the tiller and a loose plastic shield that wasn't really shielding anything.  Underneath there was a rubbery layer of old caulk that had long ago ceased sealing anything.  It peeled right out without effort.  Now there is about a 4-6" radius area around the rudder stock hole where the cockpit sole is a little "soft".  It depresses a bit when you step on it.  See attached photos.  

The fiberglass floor of the cockpit seems OK (spider cracked but still structurally OK).  And I see from crawling under the cockpit that the fiberglass under the cockpit seems OK.  The leakage comes down around the outside of the long fiberglass tube that the rudder stock sits inside of.  

My plan is to get a 6x8" plate of some material (stainless steel?  white plexiglass?) and cut out an oval to match the size of the fiberglass tube.  Then I'll seal this plate onto the cockpit floor, with screws into the floor and butyl (bed-it) tape to seal the edges.  I suppose an alternative would be to just epoxy the entire plate to the cockpit floor, rather than making it removable with screws.  This would be structurally strong and unlikely to leak, but I'm a little leery of doing "repairs" that are irreversible.  

What is the construction of the cockpit floor?  Is it plywood sandwiched between fiberglass?  I thought I heard that these older Pearsons did not have plywood cores to their decking.  But perhaps the cockpit floor is different.  I just want to get advice about what I'm drilling into, if I'm going to attach the repair plate to the floor with screws.  

I'd appreciate any advice you may have. 
Many thanks!

-- Jim

[Guy Johnson]

Jim, good pictures they really help the explanation.

However, you decide to address the problem you'll want to make sure everything is dry and well sealed when you reassemble the pieces. 

I had some spider cracks in the cockpit sole around the rudderhead on Puffin. I used a similar solution as proposed with a piece of 1x6" teak that spanned the width of the cockpit sole. The rudderstock is vertical on the 10M, so i made a simple circular cutout that supported the rudder tube. I bedded the teak in 5200 and thru bolted it to backing plates underneath the cockpit sole. 

That was over 25 years ago. 

Guy

Puffin 10M #6

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From: pearso...@googlegroups.com <pearso...@googlegroups.com> on behalf of Jim Almendinger <almendi...@gmail.com>
Sent: Monday, October 30, 2023 2:59 PM
To: pearson-boats <pearso...@googlegroups.com>
Subject: [pearson ] Leak through cockpit sole around rudder stock

 

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[Jim Almendinger]

Guy --

Good advice & thanks.

-- I hadn't considered going the full width of the cockpit.  Did you do that to add structural soundness? 

-- I hear mixed messages about 5200, mostly that it is essentially a permanent sealant, which is only an issue if you want to disassemble the pieces. 

-- Through-bolting sounds bomb-proof.  Probably the right thing to do.  I hadn't thought about it. 

-- One of my concerns is if I have to remove rotten, punky wood sandwiched between the fiberglass.  I'm just not sure how the floor is constructed. 

Thanks again for the advice,

-- Jim

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[Dan Pfeiffer]

I expect the construction of the cockpit floor on your Coaster is the same as the other Pearsons of this era (apr 68 to 82) and others.  An outer skin layup of roving/mat that is on the order of 3/16" thick, end grain balsa core 5/8" thick, and a inner skin done by chopper gun that caries in thickness from 1/8 to 1/4.  There may be some mat in there too on the inner skin.

I had a similar leak around the rudder tube on my P26.  The core got wet and I ended up removing a very large section from below and patching it with new balsa and a new inner skin panel I made from roving and mat with epoxy.  It was considerably stiffer than the OEM as the core was 3/4 balsa since I could not find 5/8.  And the skin was stiffer.  See details here:
http://dan.pfeiffer.net/p26/cfloor.htm

If you had a leak here is is very possible you also have wet core.  And the water migrates through the core. I wonder if all that cracking in your gel coat on the cockpit floor is because the core is wet and no longer supporting the outer skin and the cracks are from the skin flexing. I think the best repair is made from below with removal of the inner skin rather than the outer skin.  That's because the outer skin is a much stronger layup with roving/mat.  But I had excellent access to that inner skin on the P26 with no inboard machinery or tankage.  Still, if faced with the same repair on My 10M I would make every effort to work from below on the inner skin.  The structural and water-tight integrity of the outer skin should be maintained if at all possible.  Any repair patches made will be inferior in strength to the original layup. 

Maybe you have dry core (but probably not...).  Fingers crossed...The boat is only 55 years old?

If you add a patch plate on top (or below) I would use structural fiberglass as like what the have at McMaster Carr.  You will get far superior bonds with epoxy between this and the existing fiberglass surfaces (with all the proper surface prep).
https://www.mcmaster.com/products/fiberglass/
In fact, if I were doing the repair on my P26 today I would use this stuff rather than doing the layup myself. 

I would avoid fasteners through the deck if possible.  Just more potential for future leaks and they will need repair in another 55 years. 



Dan Pfeiffer

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[Jim Almendinger]

Dan --

This is fantastic information and advice -- thanks so much.  Now I know more of what I'm dealing with.  I can see that I'll need to do some exploratory drilling to scope out the expanse of bad core. 

I like your web site, by the way -- all content and no glitz.  Thanks for documenting all your repairs and methods.  It's a gold mine.

Cheers,

-- Jim

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[Jim Almendinger]

Just to complete this thread, my solution was to epoxy a 12x12" plate of garolite around the rudderstock.  I burned through 3 sabersaw blades in rounding the corners and cutting the central ellipse in the garolite.  I used a belt sander (held upright in a vise) to smooth and bevel the edges, and a half-round hand file to match the angle of the rudderstock on the fore and aft edges of the ellipse.  I cleaned off the cockpit sole as well as possible and finished with an acetone wipe.  I taped the outline of the plate on the sole, leaving about 1/16" outside to allow for a bit of epoxy to ooze out.  I applied fairly slow setting West marine epoxy to both surfaces with an old brush, set everything in place, built a short crib of 2x4s to get above the rudderstock, and weighted everything down with two 40 lb bags of softener salt.  After a few hours (before the epoxy hardened), I peeled off the masking (blue painter's) tape.  Seems fairly bombproof.  I suppose I'll paint it at some point.