Wood rot

Apr 11, 2017
571
Catalina C22 Solomon's Island, MD
I just had an unpleasant discovery last weekend-

For some reason, the original owner of my 87' had drilled a 1/4" hole completely through the starboard bench/settee just about 3 inches back from the cabin bulkhead. It apparently was completely sealed at some point later, but while on my lying back in the starboard quarterberth, I noticed the original hole in the underside of the settee. By tapping and visual inspection of the bottom of the through drilled hole, there appears to be about a 2 inch deep (fore and aft) by 4 inch wide (port & starboard) area of plywood rot in the laminate. This is the very end part of the plywood laminate the settee is made of, right up against the cabin bulkhead, just astern of the electrical panel. It seems to be completely dry now, and seems like it has been dry for years.

On the topside, the fiberglass seems absolutely solid, no hint of even the smallest flex, and there are no stress cracks whatsoever indicating a problem. I'm confident no more water is getting into the plywood, as the original through hole is well sealed, and looks like it's been re-sealed for years. I don't notice any type of powdery dry rot coming out of the underside of the original hole, and when I poke around in it, a few small pieces of old black plywood have come out.

I was thinking of injecting as much 2 part epoxy sealant up into the area through the bottom of the hole that I can get up there and leaving it go at that. I spent about an hour tapping around while lying on my back in the quarterberth, and despite my worrying nature, I really believe the existing area of rot is well confined, and really only about 2" x 4" in the worst case scenario, it could be 1/2 that. The fiberglass in the area seems quite structurally strong, as this is just at the very end of the plywood sandwich, and the fiberglass curves up into the vertical cabin bulkead just adjacent to this small area of rot, right at the end of the original plywood panel.

Does anyone think a larger repair is needed, or the the rot will spread laterally down the length of the plywood settee, even if no new water is getting in?

Also, I'm sure this is a dumb question, but is there any plywood in the vertical transom of the C22? Mine seems like an inner liner and outer liner sandwiched together, but I'm sketchy on whether there is plywood in between.

Thanks for any thoughts, this forum really has been great-
Mike
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Do you have photos of the location of the rot ?
I also have an '87 and am not really clear on where the hole was drilled/rot occured.
You said near the bulkhead, but said it was astern of the electrical panel. You mean the plywood bulkhead that separates the starboard cockpit locker from the settee ?

As for the transom. I was "potting" a hole made by a previous owner, for the outboard's alternator, and it looked like it was nothing but glass at that location, but it was hard to tell if it had been potted before.

Cheers !
 
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Apr 11, 2017
571
Catalina C22 Solomon's Island, MD
I'm sorry - trying to be more clear-

The hole was drilled completely through the starboard cockpit bench seat, about 2 inches back of the vertical wall of the cabin (to the starboard of the cabin bin board entrance). Trying to find the right terminology is tough.. I don't have a photo handy, or I'd post it right now. If you were short, and lie on your back in the quarterberth, it would be right above your head.

Unfortunately, seeing this problem makes me worry about every hole drilled in the deck of a 30 year old boat. All else seems well enough, but I think the ultimate best course of action would be to remove all the fittings and re-bed with butyl tape. I also have a little bit of water damage on the teak veneer bulkead, where at some point water came through the deck along the upper shroud chainplate and down the bulkhead the upper chain plate is bolted to. One thing at a time though - I bought this boat in May, and between working 60 hours a week, I haven't even had it in the water yet. Making progress though..
 
Apr 17, 2011
5
Catalina 22 #7230 Iowa City, Iowa
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
The hole was drilled completely through the starboard cockpit bench seat, about 2 inches back of the vertical wall of the cabin
Ahh ok that makes more sense....

Personally, I'd just fill the rot with epoxy, but I'm not expert by any means.

Opening the original hole, by drilling the hole all the way through again, and filling it from the top with thinned epoxy or git rot, with tape over the bottom would work well. Filling from the bottom would be hard to do, and would likely not get all the air bubbles out. All depends on if the seat surface has been repaired/painted, and your desire to do that again.

(other people, like @CloudDiver would remove the whole seat, and build a new one out of carbon fibre ;) )


When I rebuilt my sliding hatch, and was bonding the bottom skin on, there was a large area of hollow space in a few places between the skin and the repaired core. I simply kept pouring epoxy into 4 or 5 holes in the bottom fibreglass skin, until it came out the other holes, and was filled.
You will know pretty quickly if the void in your cockpit seat, is larger than you think, by how much thinned epoxy you use. :)


seeing this problem makes me worry about every hole drilled in the deck of a 30 year old boat
So it should. Like you say, I'd gradually re-bed/seal all the deck penetrations at the very least.
Like many others, I'm in the process of lining every hole with epoxy, by filling and re-drilling each one, so that any leaks simply allow water into the boat, with no risk to the core.

I also have a little bit of water damage on the teak veneer bulkead, where at some point water came through the deck along the upper shroud chainplate and down the bulkhead the upper chain plate is bolted to. One thing at a time though - I bought this boat in May, and between working 60 hours a week, I haven't even had it in the water yet. Making progress though..

My 87 also had the same damage to the bulkheads,due to the goofy chainplate design. That's what triggered my rebuilding of them and modifying the galley for more storage. Check out my refit thread for some photos of lining the chainplate deck holes.
C22 New Style "Stormwatch" Purchase and Refit

Don't feel bad. I bought my boat in 2015, and have had it in the water for 1 hour so far. (when it tried to sink via a leak through the old depth transducer).
I've slept in it, and used it as an RV, more than it's been in the water. LOL

Due to work, I barely get any time to work on it.
To make matters worse, the local chandlery is closed on summer weekends, and only open when I'm at work.
She'll likely be more or less ready by the weekend, when I get the 12v power back together, along with a working depth finder, and do a couple other little jobs like installing a safety chain on the trailer for the bow eye.

Not sure about getting time to actually use her though.. sigh.

At least I've been on OPBs a few times.

As long as you get on the water before @CloudDiver does, it's all good. :D
 
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Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
guessing the build practices might be similar across the years
Similar but not the same. One major listed update in the "new style" boats was less wood coring used.

I'd love to find out the actual details. I keep hoping @Gene Neill will cut his New Style up so we can find out for sure. He's got a bigger second boat anyhow. :dancing::poke:
 

Bilbo

.
Aug 29, 2005
1,265
Catalina 22 Ohio
The Chainplate leak seems to be common on the 2nd gen new styles. It will run down the front of the bulkheads into the V-berth area and rot the fabric and the bulkheads at the bottom screws...at least. There is a SS rectangular cover over the chainplates that is screwed to the deck and there needs to be a flexible seal under that SS cover. I'm afraid that I have used silicone to caulk here to create a flexible seal and I understand other's view on that junk on a boat but in this one situation it has worked excellently with no leaks for about 10 years now.
 
Sep 30, 2013
3,538
1988 Catalina 22 North Florida
Wait, you wanna know about new style transoms? If so I got you covered.

EDIT, just re-read the OP. Missed that last paragraph.

The only plywood I've found is around the scuppers. There might be something going on around the motor mount, but I haven't had to mess with that on this boat yet.

Here is the cross section, at the scupper:
 
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Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Which direction is that ? looking inwards from the hull to the cockpit ?

Even the liner/cockpit glass looks thicker at the scuppers than the area above that, where you cut the hole to swap to the larger gudgeons/pintles.



I'm guessing they added material the scupper area, so the scupper tubes didn't go through a void.
 
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Apr 22, 2016
161
Catalina 22 Folsom Lake
Which direction is that ? looking inwards from the hull to the cockpit ?

Even the liner/cockpit glass looks thicker at the scuppers than the area above that...
I'm guessing they added material the scupper area, so the scupper tubes didn't go through a void.
Looks like it is shot from cockpit to hull. The construction looks like what has been shown in other photos of cockpit rebuilds, two layers of plywood sandwiched below cockpit liner.
 
Sep 30, 2013
3,538
1988 Catalina 22 North Florida
Yes, it's shot from outside the hull, looking in. Our transoms look the same at the upper gudgeons. Hollow all the way up.

Next time I'm on board, I'll try to look toward the motor mount, and see if there's wood there.

Which direction is that ? looking inwards from the hull to the cockpit ?
 
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Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
Yes, it's shot from outside the hull, looking in. Our transoms look the same at the upper gudgeons. Hollow all the way up.
So maybe the transom IS solid glass, with wood only between the hull and liner/cockpit anywhere it has bolts or stuff running through both of them ?


Next time I'm on board, I'll try to look toward the motor mount, and see if there's wood there.
Yeah. I wonder if you can see it through the access hole.

I have wondered about motor mount strength/rot when I bought my new motor, but as you know, you can't simply crawl into the stern port side and access between the liner and hull. When I bought the boat I had assumed that there was no liner there. I plan on refurbishing the mount this winter, and will be lining the holes with epoxy, along with the scupper tubes.

I have access to a cheap bore scope at the shop, maybe it will allow me to see in there. I'll try to remember to bring it home.
 
Apr 11, 2017
571
Catalina C22 Solomon's Island, MD
Well - my original concern - plywood rot caused by a hole drilled through the starboard cockpit bench seat about 2 inches back from the cabin wall - doesn't seem that big of a deal now.

Not able to stand the worrying suspense, I dug into it with an awl while lying down on my back in the quarterberth. The construction I found, when digging up from the underside, was this: A fairly thin (probably single layer) layer of fiberglass mat (the white-grayish painted quarterberth ceiling, with the black paint splash pattern), then 1/4" of plywood, then about 3/16" inch (maybe a little more) of solid fiberglass matting, ending in the gelcoat non-skid pattern of the bench seat. It really appears about 90% of the structural strength comes from the 3/16" fiberglass layer, and the stiffening corners and curves it is laid out into, rather than the skimpy 1/4" plywood.

My area of plywood rot really only seems to be about the size of a silver dollar around the original drill hole that caused the problem. I scratched away at it, got to where it appears to be solid plywood, and I think I'm just going to squeeze some 3M 5200 up into there, that I already have on hand, and call it good. The bench seat itself seems solid as the rock of Gibralter from the topside.

My biggest worry was it was more like 1/2" plywood, and the rot had worked it's way back all along the bench seat. I can't really see where the 1/4" plywood the seat is built from adds all that much strength by itself, and the way the fiberglass is shaped seems a strong design, with molded fiberglass corners close by everywhere to stiffen it up. I'm also into archery, and I can say from that hobby, good fiberglass is some super tough stuff..

I will say - the fiberglass layup in the C22 seems solid and thick for a 22 foot boat, and it looks like good quality woven mat. I feel better about the situation, so just gotta finish up the rest of the new electrical wiring, add the split backstay fitting, and some other odds and ends, work on the trailer, and put her in the water. The list is getting shorter...

Thanks again to everyone for all the great advice I've gotten on this forum-
 
Mar 20, 2015
3,094
C&C 30 Mk1 Winnipeg
They used 1/4" ply for the cockpit seat ? Hmm I wouldn't have expected that. Good to know. :)
 
Sep 30, 2013
3,538
1988 Catalina 22 North Florida
My '79 had a leak in the port cockpit seat. Some PO had "sealed" it, with clear silicone, from UNDERNEATH.

Needless to say, that whole piece of plywood was shot.
 
Apr 11, 2017
571
Catalina C22 Solomon's Island, MD
My '79 had a leak in the port cockpit seat. Some PO had "sealed" it, with clear silicone, from UNDERNEATH.

Needless to say, that whole piece of plywood was shot.
Did you cut it out and repair it? That's what I was worried about myself, and it seemed like a nightmare job. I'm fairly new to this though-
 
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Sep 30, 2013
3,538
1988 Catalina 22 North Florida
Heck no, I sold the boat! :biggrin: To be fair though, it had a lot more problems than just that.

Pics would be really helpful, but situation with your bench sounds very minor. If the original hole that was drilled through the bench has been properly sealed (as in, filled with epoxy), then I would just try to grind out the rot from underneath, and smear some thickened epoxy (peanut butter consistency) across the void where the rot was. Maybe apply a small fiberglass cloth patch over the thickened epoxy before it cured, just to make myself feel good. At most.

Personally, I wouldn't bother with the 5200, if you haven't already. It won't do much except complicate a more thorough repair, should one ever become necessary.


Did you cut it out and repair it? That's what I was worried about myself, and it seemed like a nightmare job. I'm fairly new to this though-
 
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Sep 14, 2014
1,251
Catalina 22 Pensacola, Florida
Really, it seems like a pretty small problem, besides give you chance to exercise the bilge pump and practice fiberglass repair techniques.
 
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