What kind of deterioration is this, and what's the fix?

ChrisC · Post by **ChrisC** » Tue Jun 06, 2017 12:03 pm

Hi all. Cleaning my C-22 in preparation for launch I found something disconcerting yesterday. It is an area of deterioration in the forward settee on the port side. This is on what I guess would be called the keel trunk, in an area above the keel bolts, very close to the top of the settee.

Here are two photos:

I do not know what the brown material is inside. Is it some kind of core material (wood), or is it fiberglass? It's soft when poked with a knife. More importantly, what's on the other side of it?

I though it was a dirt smudge at first and sprayed it with cleaner and wiped, and the material came out.

Oddly, the covering of the inner area here is a very thin coat of maybe paint (?) or resin over this material but does not appear to be fiberglass. (Unless this is some kind of delamination.)

Does anybody know what's going on here? How serious is this? (It looks serious).

I don't recall seeing this last year, so either it wasn't so visible or this is new.

And secondly, how do you fix it? Grinding and fiber glassing perhaps?

Thanks for any help with this. I'm going to take a closer look at this material now.

Chris

Reality · Post by **Reality** » Tue Jun 06, 2017 5:03 pm

One would expect that the keel trunk is formed from wood and fiberglassed. Unfortunately I'd guess that's the wood core and it's rotten. Since the keel trunk is a major structural member I'd think this is very serious and would not use the boat until resolved. Sorry

ChrisC · Post by **ChrisC** » Tue Jun 06, 2017 6:19 pm

Yeah, I hear you. I scraped some of that out, and it does seem to be wood that has become degraded, rotted, whatever--it fibery. I think I agree with you, but I was hoping (am still hoping) a knowledgeable person says, hey it's not a problem. I think if this area loses its structural integrity, the boat sinks.

Repair process? Dig out the bad wood and back fill with structural epoxy if it's a small area (something like Marine-tex)? If it's a much larger area, the entire wooden section probably needs to be replaced.

I don't know if I know how to do that.

Reality · Post by **Reality** » Tue Jun 06, 2017 6:30 pm

I think failure on the water could mean the heavy swing keel rips the bottom out of the boat and everything sinks very fast. I'd suspect you'll be removing the swing keel and rebuilding the trunk, or scrapping the boat (sorry). Please error on the side of caution/safety.

ChrisC · Post by **ChrisC** » Tue Jun 06, 2017 6:46 pm

I'm sure it can be rebuilt, but the question is how to do it and how long would it take; or how much would it cost to have a shop do it.

I guess I'm glad I saw that, I was hoping to get it in the marina next week. An even scarier thought is that even though I didn't see it, or it wasn't visible last season, it must have still been compromised to some extent, and I sailed it for 5 months that way.

Anybody have suggestions on how to repair it?

C22Bob · Post by **C22Bob** » Wed Jun 07, 2017 5:05 am

ChrisC wrote:I'm sure it can be rebuilt, but the question is how to do it and how long would it take; or how much would it cost to have a shop do it.

I guess I'm glad I saw that, I was hoping to get it in the marina next week. An even scarier thought is that even though I didn't see it, or it wasn't visible last season, it must have still been compromised to some extent, and I sailed it for 5 months that way.

Anybody have suggestions on how to repair it?

Chris,

The keel trunk is basically a plywood box that has been glassed and gelcoated for waterproofing. It does not actually support the keel entirely. It just forms a box for where the keel can retract into. Look for yourself how the keel is mounted. Notice that the bracket that holds the 900 lb. keel is actually fastened to fiberglass that is formed as part of the hull. Here's a previous post of mine where we discussed

http://www.chryslersailors.com/discussi ... highlight=
http://www.chryslersailors.com/discussi ... highlight=

The fiberglass at that half moon cutout area is about a 1/4" thick. The underlying hull at that area is about an inch think.

It's the fiberglass that's holding your keel in the boat, NOT the plywood box!! Having said that, the plywood box does provide structural shape and some support of the keel weight. You need it to be sound. So, in your case, is the rot in a small area? If so, you could be lucky and just cut out the wood completely there. If so, bolt a patch over the hole and seal. The patch material could be stainless steel plate, PVC plastic sheet, etc...Keep in mind the plywood is about 1/2" thick. I don't think you're looking at a huge repair cost.

Hope this helps

Bob

ChrisC · Post by **ChrisC** » Wed Jun 07, 2017 8:51 am

This is good news! Thanks for the input. Reading some other forums last night, I was beginning to think maybe there was some hope. I will read through your posts carefully and today I'll explore the extent of the rot. I may contact you with some specific questions.

jsa · Post by **jsa** » Wed Jun 07, 2017 10:43 am

I wish I had more advice for you, but I'm pretty new to the Chrysler.

Others may disagree, but I've always thought of Marine-Tex as a temporary fix. I think of it as something to get the job done until the job can be done right. It claims to be structural, but it is just epoxy and filler. I wouldn't trust it over large areas. That is just my opinion though from my limited experience.

There is an epoxy made for deteriorated wood called Git-Rot. It's basically just thinned epoxy, but it is ready to go. Just add the catalyst and get to work. It is a penetrating epoxy. I'm not sure how well it would work on vertical surfaces though. I've used it to fix delaminated areas on hobie cats before.

Best of luck with your repairs. Keep us posted!

ChrisC · Post by **ChrisC** » Wed Jun 07, 2017 7:37 pm

Thanks for the tip on Gut-Rot, I may use that.

I did some more poking around and found that the rot is fairly extensive. The top portion of the plywood seems solid, but it's rotted, and in some spots still damp (!), down toward the bottom of the compartment and to the "half moon" around the keel pin mount.

However I felt optimistic when I saw the the function and placement of the plywood:

As you can see, it could, in theory, be replaced or somehow shored up. It's purpose seems to be to provide some lateral support to the keel trunk. The cut in the top left is actually rather surprising, and the not so great covering with whatever is pretty poor workmanship.

Now I want to open the rubber plug to see the starboard side of the keel assembly. I know some of you have opened this plug: will I destroy it if I open it?

It still seems fairly flexible from working with the edge a bit.

One thing that concerns me is when I was moving the edge around some water leaked out. I wonder if the area between the hull and the interior is full of water?

And is the plywood there rotted as well?

I suppose the likely source of water would be the keel bolt, the rudder through hull, or a poor seal at the deck and hull joint.

I'll let you know what I find. Any other advice or experience would be greatly appreciated.

Thanks,
Chris

Reality · Post by **Reality** » Wed Jun 07, 2017 8:16 pm

not at all an expert on the C22 keel, but there are more forces while under sail than just "supporting" the weight of the keel. Guess I'm overcautious, but in my experience of doing 30 years of hardware design I'd think the entire hull including the trunk act as a single "monohull" structure. There have to be tremendous side forces attempting to twist off the keel when heeled over. This would include lateral upward forces. Please be extra cautious and do some sea trials after repair with a chase boat.

CaptainScott · Post by **CaptainScott** » Wed Jun 07, 2017 8:27 pm

FYI I have pulled the starboard plug that you describe on 4 c22's without issue. Please note they were all pulled on the hard. Never in the water. No reason other than it is my way.

They all went back in place reasonably easy.

Scott

C22Bob · Post by **C22Bob** » Thu Jun 08, 2017 4:58 am

Reality wrote:not at all an expert on the C22 keel, but there are more forces while under sail than just "supporting" the weight of the keel. Guess I'm overcautious, but in my experience of doing 30 years of hardware design I'd think the entire hull including the trunk act as a single "monohull" structure. There have to be tremendous side forces attempting to twist off the keel when heeled over. This would include lateral upward forces. Please be extra cautious and do some sea trials after repair with a chase boat.

A very good point for sure. The entire keel trunk 'box' should be sound. A sailboat at rest is a lot different than under sail and heeled over definitely places upward stress on the keel trunk.

Bob

C22Bob · Post by **C22Bob** » Thu Jun 08, 2017 5:12 am

ChrisC wrote:Thanks for the tip on Gut-Rot, I may use that.

I did some more poking around and found that the rot is fairly extensive. The top portion of the plywood seems solid, but it's rotted, and in some spots still damp (!), down toward the bottom of the compartment and to the "half moon" around the keel pin mount.

However I felt optimistic when I saw the the function and placement of the plywood:

As you can see, it could, in theory, be replaced or somehow shored up. It's purpose seems to be to provide some lateral support to the keel trunk. The cut in the top left is actually rather surprising, and the not so great covering with whatever is pretty poor workmanship.

Now I want to open the rubber plug to see the starboard side of the keel assembly. I know some of you have opened this plug: will I destroy it if I open it?

It still seems fairly flexible from working with the edge a bit.

One thing that concerns me is when I was moving the edge around some water leaked out. I wonder if the area between the hull and the interior is full of water?

And is the plywood there rotted as well?

I suppose the likely source of water would be the keel bolt, the rudder through hull, or a poor seal at the deck and hull joint.

I'll let you know what I find. Any other advice or experience would be greatly appreciated.

Thanks,
Chris

Chris,

Pulling that rubber plug is no big deal, and you definitely need to see what's on that side. If full of water then pump out and let dry. You may need to cut some access holes in the liner to inspect the starboard side of the keel trunk. I know that won't be pretty, but you may have some rot on that side too. I hate to say it, but if you encounter a lot of rotted trunk you may have no choice but to cut out all the liner around the trunk. Yes, won't be pretty to patch back together but you can't sail safely without a sound keel trunk. Keep us posted how it goes, and good luck..

ChrisC · Post by **ChrisC** » Thu Jun 08, 2017 9:27 am

Thanks everybody for the advice and the words of caution. I agree that there must be extraordinary forces on the keel trunk, which explains the wood reinforcement. But it is also surprising at how simple (or minimal?) the reinforcement is.

The plywood appears to be attached to the trunk with a layer (or maybe two) of fiberglass. The forward side of the wood is glassed into the forward side of the settee, which along with the partition that forms the backrest of the settee creates a bulkhead separating the v-berth area from the dinette area. The mast compression post rests on metal shims on top of the keel trunk. So this is designed to provide some stiffness and solidity. The plywood panel is only one (but critical) area where the interior insert is connected to the hull to provide overall support.

I cannot tell how long to plywood is, if the the edge of the wood reinforcement is even with what is visible (i.e. the aft side of the settee storage compartment), or if it follows the rest of the keel trunk as it tapers downward.

I am hoping that I can find some clear borders to the rot area and then maybe do two things. First, cut or chisel out the rot and fill the area with something like the Git-Rot to basically create a new artificial board; and then cover this area with a patch of metal or heavy PVC as C22Bob suggested, and maybe bolt and glass that in.

Another way, maybe better alternative, would be to remove as much of the board as possible down to the fiberglass keel trunk, and replace it completely with a new board that is held in place with some combination of fiberglass, resin, and screws. I'm not sure how to get the wood out--I suppose grinding or sanding it down to the fiberglass. I don't know if this whole idea even makes sense.

And of course, the same may have to be done to the starboard side as well.

Depending on what I find I may take this to a shop. I don't have much experience with this sort of thing, and I would l like to have it done well rather than poorly but cheaply.

But I guess there's a trade off. It could cost more than I paid for the boat.

I'm reminded of those old jokes: Boat = "Break Out Another Thousand"; or "a boat is a hole in the water where you throw money."

I'll keep you posted.

C22Bob · Post by **C22Bob** » Thu Jun 08, 2017 10:07 am

ChrisC wrote:
I'm reminded of those old jokes: Boat = "Break Out Another Thousand"; or "a boat is a hole in the water where you throw money."

I'll keep you posted.

ChrisC · Post by **ChrisC** » Thu Jun 08, 2017 10:44 am

Perfect!

EmergencyExit · Post by **EmergencyExit** » Thu Jun 08, 2017 12:06 pm

LOL. I am looking at that very cartoon right now - already had it pinned to a corkboard over my desk....Classic !

ChrisC · Post by **ChrisC** » Mon Jul 10, 2017 4:49 pm

UPDATE:

I have continued to work on my boat and this rotted wood situation. I expect I will be done in about 2 weeks, maybe less.

Here's a more current pic for reference:

I ground down the rotted wood to a hard wood surface or to the fiberglass. Since this photo was taken I have removed the wood on the lower sides down to the fiberglass.

It turns out that the plywood panel joined the sides of the setee (more or less visible at the extreme edges of the photo) to the keel trunk. It's an interesting and crucial junction that provides stability--the wood was embedded 1/2 inch into the bottom of the hull, glued to the keel trunk and the sole, which provides some kind of lateral stability against deflection. The compression post for the mast also sits on top of the keel trunk, so keep that area stable seems like a good idea.

Here the fix: I will replace (glue in) the areas I've taken down to fiberglass with 1/2 inch plywood that I've sealed with penetrating epoxy. The remaining would will be treated with penetrating epoxy in two ways: I will drill shallow 1/4" holes into the wood into which I will eject the epoxy; and then I will "paint" the surface of the wood with the epoxy as well.

Once that is set up, I will use an epoxy glue with silica and screws to join another piece of plywood over the entire area. I may glass ove the edges, but I don't think I will need to. This set up should provide plenty of support for the keel trunk.

I decided to use TotalBoat epoxy and epoxy glue after a lot fo reading and research. The entire epoxy and wood issue is "controversial" (I guess that's the right word) and with many conflicting views, strong opinions, and fights. Check out what's going on at the Wooden Boat Forum if you really want to see some goo knowledge and see some folks get into extended arguments about epoxy!! http://forum.woodenboat.com

Anyway I settled on the TotalBoat penetrating epoxy because it's a low viscosity epoxy but without solvents (or not a lot of solvents) and has a lot of solids, as they say, which creates a strong seal. Their products are also less expensive and their telephone support was helpful.

HOWEVER, this project has also brought to my attention some other issues. I am starting new threads on those to keep issues separate and simpe. I think I can get my boat in the water for the rest of the season, but I will need to address these for the 2018 season.

Thanks everybody for the help, suggestions, epoxy ideas, and useful information. Take a look at the other threads.

I'll post pictures as the repairs actually take place.

Edit: one more thing: the stabilizer--it no longer has the nylon or teflon end or whatever. Just a metal pipe that maybe provides some stability (or not). Would you suggest removing this altogether or replacing with a new one? Thanks.

C22Bob · Post by **C22Bob** » Tue Jul 11, 2017 4:41 am

Chris,

Here's a link to a post showing the original keel stabilizer with plastic rod inserted. Plastic is either Nylon or UHMW PE or some other high density material. Best bang for the buck is UHMW PE, super strong and cheap.

viewtopic.php?t=4852

Most people on this forum don't put much stock in the effectiveness of this device. If only one one side, I tend to agree. That's why I modified my Chrysler with a port and starboard side stabilizer and used stainless rather than plastic. I think the stabilizer is a good idea if used like this.

ChrisC · Post by **ChrisC** » Tue Jul 11, 2017 3:50 pm

Thanks for the input and the photos. That is a beaituiful stabilizing set up you made. Inspiring. Maybe next season. I do have some worries about leakage around the stabilizer. Maybe I'll take it out if I'm feeling ambitious; or maybe wait until next spring.

Reality · Post by **Reality** » Tue Jul 11, 2017 10:42 pm

hmm, I'd think the stabilizer is an important functional element of the keel design. As a former 30 year mechanical designer it should help reduce the force (wear) on the pivot pin.

C22Bob · Post by **C22Bob** » Wed Jul 12, 2017 6:03 am

I tend to agree. I think of it like this...imagine the boat in mid air, now lower the keel 60 degrees, not heel the boat over 20 degrees. Has gravity had an effect on it,..you betcha! I'm guessing Chrysler had that in mind when adding it to the later models. Again, to be the most effective you need support on both sides. My guess is that they abandoned the starboard side for cosmetic reasons since there's little to no space between the liner and plywood trunk.