Uh oh! Recore foredeck

May 24, 2020
6
Catalina 22 garage
Ambitious newbe here. Picked up a 1976 C-22 for a good price and now I know why. Leaky hatch, rotted foredeck. I thought I'd try the repair from below. I've removed the overhead liner for the length of the v-berth and cut out the rotted ply. Only the top skin is left. Now I'm rubbing my head and wondering if I've bitten off more than I can chew. What do you think? Is this hopeless?

A little reading around suggests that several of you have fought this battle.

I need a little encouragement. Point me in the right direction folks.
 

Attachments

Sep 22, 2018
1,869
Hunter 216 Kingston
I don’t know what to say. Here is recent thread that shows a somewhat different approach.

 
Sep 22, 2018
1,869
Hunter 216 Kingston
I apologize if I discouraged you by my previous post.

Quite a few experienced Cat 22 owners here that can provide better advice than me.

I’m not really sure looking at your photos what the current state is. Is the brownish surface with the rectangular hole in it wood or the inner part of the sandwich?

Typical sandwich is an inner layer of fibreglass, a layer of wood referred to as the “core” then an outer layer of fibreglass. The individual layers by themselves aren’t particularly stiff or strong but the three together (sandwich) is.

It would help if you could provide additional photos and a detailed description of where you are now.
 
Jan 1, 2006
7,039
Slickcraft 26 Sailfish
Since there is likely a bow in the deck you might consider using thinner sections of marine ply which would be flexible and laminate them each one at a time to make the "Core." You can use deadmen or jacks to rig up gentle pressure to press the board up against the deck skin. It'll take some imagination but great satisfaction in accomplishment. They don't need to be a perfect fit. Gaps at the edges can be filled with epoxy filleting and in the end tape.
 
Mar 29, 2017
576
Hunter 30t 9805 littlecreek
Last one I did I installed ripped aluminum sheet to give extra strength then used closed cell spray foam and dead jacked ceiling back in. foam made a mess thou
 
May 24, 2020
6
Catalina 22 garage
Thanks all for the encouraging words. "Stout of heart," shemandr, that's good stuff! Thanks all! Here's a bit more information, Hunter216, if it helps. I'll key my comments to the added photos below. (1) View from above. Topside skin looks good, stripped of all hardware. Thankfully, I was able to do the work from below without causing any damage to it. (2) My problem all started, seemingly, with a leaky hatch. You can see the delamination around the edges, once the frame is removed. How far back did the water damage go? Tap! Tap! Tap! (3) I made a first cut around the hatch with a dremel tool, careful to cut the liner but not what was beneath. It didn't look good. Since the liner didn't seem to be connected at all to the wood above, I figured I didn't have much to lose. So . . . (4) I made another cut with the dremel straight across the boat, aft of the hatch, just before the rise of the "doghouse" (is that what you call it, the elevated headspace in the cabin?). (7) One hard knock and the whole liner let go and came down on me! Is it just glued up there? Here it is "glue" side up on my driveway. You can see the square of my first cut around the hatch, and the rest of the liner as it came down. (6) A closeup view of the backside of the liner reveals that it had separated from the plywood almost entirely. What looks like thin plywood on the liner is merely a wood grain imprint into the thin "glue" that is very brittle and cracks between the fingers (sorry about the order of the pictures.) After the liner came down, I went back in (respirator on) and pulled down most of the plywood with my fingers and small pry-bar. In a few areas I used a hammer and chisel, careful not to penetrate the outer skin. I ran a sander over it to clean it up. Note in picture (4), there is one section of the plywood that still seems to be in pretty good shape and is in solid contact with the skin. I don't know if I should tear that out or not? Would the rebuilt be easier if I removed it or left it? (5) shows the current state of things, a poor photo of a "cross section," showing the outer skin and the one remaining corner of ply (1/4" I'd guess). Finally, (8) looking aft, on the starboard side, the ply seems to be in good contact with the liner. However in photo (9) looking aft, you can see a pretty good gap developing between the ply and the liner. Do I need to keep cutting back that liner, or can I epoxy the heck out of it and jam/jack it up to the ply from below?
 

Attachments

Last edited:
Sep 22, 2018
1,869
Hunter 216 Kingston
@blowingbubbles
Great photos and descriptions. Welcome to SBO btw ! :)

I have few suggestions:

!) Read through some of the Cat 22 restoration threads and try to figure out an approach / materials you feel most comfortable with. You might find that there are other things you might want to do now since the demo is done. You can perhaps reach out to specific individuals to ask questions.

Like this one for example

2) Read up on how to use the current range of epoxy, foam, G10, marine plywood and synthetic alternative materials and where to source them from so you can best determine budget and time frame to get your repair(s) done and be out on the water..
 

greg_m

.
May 23, 2017
692
Catalina Jaguar 22 Simons Town
Hello there fellow boat rebuilder!

As someone who has recored the entire deck I talk from experience! It is indeed doable. Very much so. It will be just a lot of hard work. In my case I turned the boat upside down to do this job looking down. I did not see myself spend hours sanding on my back looking up into the falling dust. Also, initially I did not want to disturb the top of the deck in terms of the non slip and uniform surface. Of course I ended up sanding the entire deck down due to rotting gelcoat.

You can check my thread here: South African "Catalina" 22

There is other threads where one guy took the lid off the deck as it were and used "coosa" to replace the core. We don't get "coosa" in SA here. The alternatives were waterproof plywood or foam sheets. The plywood was cheaper! Waterproof not actual "marine grade". It is not for show.

Wish you well on all your work.
 
  • Like
Likes: Hunter216
May 24, 2020
6
Catalina 22 garage
Thanks for the encouragement greg_m! Your thread is great too. What a job you've done! I'm still studying it. Forgive me for all my questions!

I don't have the gear and workspace to flip my boat, so I'm stuck doing it on my back.

Since you went at your foredeck recore from the interior, maybe you can answer this. What I'm calling the "head-liner" in my boat had separated from the plywood core. There was no functioning (fiberglass-plywood-fiberglass) "sandwich." That liner was only held in place by a dab of this and that, the hardware backing, and by virtue of the one-piece "lid" construction of the Cat 22. Assuming I can get some new 1/4" core material securely epoxyed against the existing top skin, I was planning to lay up a new layer of fiberglass on the face of it (just like wallpapering the ceiling, right!). Do I attach (tab) that new 'glass layer (essentially the bottom side of the "sandwich") in any way to the hull itself, or do I just bring it right up to meet it? I'm also wondering if there would be any value in working in some kind of rib or stringer across the foredeck for additional support? How did you finish the interior with your job?
 
Sep 22, 2018
1,869
Hunter 216 Kingston
While your waiting for people with actual hands on experience on a C22 ;) to chime in more I thought I would offer a few ideas.

BTW if you use the @ symbol before the user name they get a message that you mentioned them.

You have decided to work over your head during the “rebuild”. Given you will be using liquid or semi liquid resins I assume you would like to minimize the “drip factor” ;)

So here is my idea for what it is worth.

Dry fit your core material and figure out how you will support it while it sticks to the underneath of the deck. Also determine how much time you need to get it all lined up. (The resin you use to adhere it to the top deck has a working time, once it starts to set you better have it where you want)

Once you have that figured out I see no reason you couldn’t stick your “ liner” layer to the core with it oriented so you can work on it oriented “wrong side up” (if that makes sense). Once it dries you can flip the core over and stick it in place.

Perhaps the interior of the boat, hatchway won’t allow you to do that but it sounds less messy to me.

One other thought I had about a method to temp brace the core in place is to inflate a car or truck tube while it’s inside the vberth area.
 
Last edited:
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
another hint: if you work with epoxy it will not cure at lower temps, read the can. if you have chilled epoxy and well below 50 ish air temps for wood and deck the epoxy will not 'kick' . there by giving you all the time in the world to get your surfaces coated and plywood in place with no rush. then bring up the temps to 70 ish and then the epoxy will 'kick' and the job well done.
i had all the plywood ,under the decks, replaced on a 69' cal 20. it was done in the winter time in northern wis.
i paid to have it done. 16 years later it still is working great
 
Last edited:
Sep 22, 2018
1,869
Hunter 216 Kingston
Thanks for the encouragement greg_m! Your thread is great too. What a job you've done! I'm still studying it. Forgive me for all my questions!

I don't have the gear and workspace to flip my boat, so I'm stuck doing it on my back.

Since you went at your foredeck recore from the interior, maybe you can answer this. What I'm calling the "head-liner" in my boat had separated from the plywood core. There was no functioning (fiberglass-plywood-fiberglass) "sandwich." That liner was only held in place by a dab of this and that, the hardware backing, and by virtue of the one-piece "lid" construction of the Cat 22. Assuming I can get some new 1/4" core material securely epoxyed against the existing top skin, I was planning to lay up a new layer of fiberglass on the face of it (just like wallpapering the ceiling, right!). Do I attach (tab) that new 'glass layer (essentially the bottom side of the "sandwich") in any way to the hull itself, or do I just bring it right up to meet it? I'm also wondering if there would be any value in working in some kind of rib or stringer across the foredeck for additional support? How did you finish the interior with your job?
On the “headliner” part. This is the interior layer of the fibreglass - wood - fibreglass sandwich. It came off easily because water intrusion had destroyed the bond between it and the wood.

Builders started using “coring sandwich layup” as an alternative to really thick layers of fibreglass. Relatively speaking lighter, cheaper and if done correctly just as strong and stiff if not more so.

Take a thin layer of FRP and you could bend or break it easily. Take a piece of core material - wood, foam etc and by itself not very strong or stiff.
Take two layers of FRP with a “spacer” or core between them and as a “unit” it is really strong. Think of a steel I-beam. The top and bottom flanges are the FRP layers the vertical is the core.

If you choose to use plywood as the core, pretreat it with penetrating epoxy to reduce or eliminate water absorption (you don’t want to do this again anytime soon. ;) )

Once you have the new “sandwich” in place you need to connect it to the hull. I understand this is done by building a ridge (fillet) at the gap along the outer edge of the new surface and the inner hull. Think of it as welding the deck onto the boat again. Skip this step and the deck is only as strong as the upper layer that you left untouched.
 

greg_m

.
May 23, 2017
692
Catalina Jaguar 22 Simons Town
Thanks for the encouragement greg_m! Your thread is great too. What a job you've done! I'm still studying it. Forgive me for all my questions!

I don't have the gear and workspace to flip my boat, so I'm stuck doing it on my back.

Since you went at your foredeck recore from the interior, maybe you can answer this. What I'm calling the "head-liner" in my boat had separated from the plywood core. There was no functioning (fiberglass-plywood-fiberglass) "sandwich." That liner was only held in place by a dab of this and that, the hardware backing, and by virtue of the one-piece "lid" construction of the Cat 22. Assuming I can get some new 1/4" core material securely epoxyed against the existing top skin, I was planning to lay up a new layer of fiberglass on the face of it (just like wallpapering the ceiling, right!). Do I attach (tab) that new 'glass layer (essentially the bottom side of the "sandwich") in any way to the hull itself, or do I just bring it right up to meet it? I'm also wondering if there would be any value in working in some kind of rib or stringer across the foredeck for additional support? How did you finish the interior with your job?
Hi BB.. I started my project wanting to redo the hull deck joint seal. The more i tried cleaning it out the more it seemed to be coming apart. The hull and lining are two layers that overlap. The deck and deck lining are also two layers that overlap. All these layers come together at the joint. I wanted to actually bond everything with epoxy adhesive and seal the hull deck joint for good from the outside. Was not bargaining on the multiple layers of the joint. So the reason i turned the boat upside down was in the thinking that "pouring" adhesive into the joint would allow it to run into the multiple layers. Turning the hull over does not require more space than the boat occupies and is actually a lot easier than one thinks. Look at Clouddivers thread... he gave my the inspiration. [Edit: of course the keel must come off or it's a little bit dodgy!]

My foredeck area around the forward hatch inside lining was cracked around the corners and the deck was a bit soft, so I cut that away with the idea of just rebuilding around the hatch only and reinforcing it a bit by adding beefy wooden structure. Unfortunately the more lining I removed the more rotten plywood laminate I found. It was also just bonded to the the deck with splodges of resin and glass mashed together. lots of voids and poor bonding actually. Lots of place for water to sit and fester!

So to answer your question... I did tie the hull joint to the deck in my rebuild. Inside and out. I cut away the lining as far as I could as close as I could to the hull/deck joint. Then i back filled the void with thickened "peanut butter" mix of resin/chopped glass strands and silica powder. Over that I glassed in woven tape 100mm wide. So in the end I have a solid hull deck joint that will probably withstand a torpedo! There will be a boat shaped rim left over but by golly it will last!

I also just added two layers of CSM to the inside to cover the 6mm ply wood. Mostly to seal the plywood from moisture. Only around the foredeck hatch area did I double the layer of plywood and add some solid wood low profile "beams" with glass layers for adding rigidity to the deck directly around the hatch opening. In the bow area I put in 12mm thick plywood piece large enough to support the bow chainplate/anchor roller fitting. I used a car scissors jack to actually bend the plywood to shape of the curved deck.

In what I percieved as "structural" areas i used epoxy adhesives while in general laminating and bonding the plywood in the other areas i simply made batches of peanut butter laminating polyester resin/glass chopped strands of 6mm length and silica powder mix. I liberally pre-coated all plywood with resin making sure to saturated all surfaces and edges before actually laying down the plywood.

Man, this seems like ages ago but I'm definitely happy with doing it.

All the best with your project
Greg
 
Last edited:
May 24, 2020
6
Catalina 22 garage
Hi BB.. I started my project wanting to redo the hull deck joint seal. The more i tried cleaning it out the more it seemed to be coming apart. The hull and lining are two layers that overlap. The deck and deck lining are also two layers that overlap. All these layers come together at the joint. I wanted to actually bond everything with epoxy adhesive and seal the hull deck joint for good from the outside. Was not bargaining on the multiple layers of the joint. So the reason i turned the boat upside down was in the thinking that "pouring" adhesive into the joint would allow it to run into the multiple layers. Turning the hull over does not require more space than the boat occupies and is actually a lot easier than one thinks. Look at Clouddivers thread... he gave my the inspiration. [Edit: of course the keel must come off or it's a little bit dodgy!]

My foredeck area around the forward hatch inside lining was cracked around the corners and the deck was a bit soft, so I cut that away with the idea of just rebuilding around the hatch only and reinforcing it a bit by adding beefy wooden structure. Unfortunately the more lining I removed the more rotten plywood laminate I found. It was also just bonded to the the deck with splodges of resin and glass mashed together. lots of voids and poor bonding actually. Lots of place for water to sit and fester!

So to answer your question... I did tie the hull joint to the deck in my rebuild. Inside and out. I cut away the lining as far as I could as close as I could to the hull/deck joint. Then i back filled the void with thickened "peanut butter" mix of resin/chopped glass strands and silica powder. Over that I glassed in woven tape 100mm wide. So in the end I have a solid hull deck joint that will probably withstand a torpedo! There will be a boat shaped rim left over but by golly it will last!

I also just added two layers of CSM to the inside to cover the 6mm ply wood. Mostly to seal the plywood from moisture. Only around the foredeck hatch area did I double the layer of plywood and add some solid wood low profile "beams" with glass layers for adding rigidity to the deck directly around the hatch opening. In the bow area I put in 12mm thick plywood piece large enough to support the bow chainplate/anchor roller fitting. I used a car scissors jack to actually bend the plywood to shape of the curved deck.

In what I percieved as "structural" areas i used epoxy adhesives while in general laminating and bonding the plywood in the other areas i simply made batches of peanut butter laminating polyester resin/glass chopped strands of 6mm length and silica powder mix. I liberally pre-coated all plywood with resin making sure to saturated all surfaces and edges before actually laying down the plywood.

Man, this seems like ages ago but I'm definitely happy with doing it.

All the best with your project
Greg
Thanks @greg_m--your response is a gold mine of needed information! Sorry about my slowness in getting back to you. My real job keeps getting in the way of what I want to do (!).

That description of the "boat shaped rim" made me chuckle. I can just imagine some mystified future archaeologist scratching his head when he digs your boat up.

I'll tie the hull and deck together for sure.

I had considered the idea of adding some kind of "beams" or ribs across the foredeck for additional support (as you describe) but wondered if it might create unintended stress or "hot points either on the hull or on the deck. Evidently you didn't have this issue. Did you run those structures all the way to the hull on either side?

I'm picturing the scissor jacks bending the 12mm plywood. Wow!

I'm still fussing in my head about the core material. Whatever I end up using, I'll have to have it shipped. It's all pricey and there doesn't seem to be anything local. I'm half-tempted to try the balsa. It might make it easier to match the curve of the deck.

In any event, thanks for the info and encouragement!
 

greg_m

.
May 23, 2017
692
Catalina Jaguar 22 Simons Town
Hi BB... the scissors jack and lots of large cement building bricks and paving bricks gave plenty bending and bonding pressure!

I used pieces of 6mm plywood in what could be described as an "H" shape. The center part of the H being double to form the square for the hatch opening. Maybe calling it a section of a ladder would add more meaning. I ran the length across the deck athwartships. Each layer bonded with epoxy adhesive. In this way I built up a low profile laminated beam that goes across the deck forward and aft of the hatch opening. I also put temporary screws through the deck to clamp everything together. These screws being removed after the adhesive had cured for a few days.

All corners rounded and edges chamfered to reduce any possible stress points. Tied into the hull/deck joint at the sides of the deck also. Each layer was slightly narrower than previous to taper the profile. It really looks good, adds super rigidity to the whole foredeck structure that I am able to walk on now the boat is upright. Have not notice any creaking or cracking so it should be good for a few decades.

Check out the process from this link: South African "Catalina" 22

as well as post #68 in my thread on page 4.

Not saying my way is the best... it's just what I though would work without taking away lots of head room if one can call it that in the vee-berth!
 
Apr 11, 2017
571
Catalina C22 Solomon's Island, MD
... In the bow area I put in 12mm thick plywood piece large enough to support the bow chainplate/anchor roller fitting. I used a car scissors jack to actually bend the plywood to shape of the curved deck.
Great idea Greg. With some blocks underneath the jack, and maybe some sort of temporary plywood and foam cut-out on top of the jack - that's really a flexible solution for overhead work. I wish I'd have known that before my last fiberglass repair. As it was - my remaining hair was epoxied together in clumps for a few weeks or so...
 
Apr 13, 2016
29
Catalina 22 Fort Worth
I am in the middle of this repair (in for a penny in for a pound). I got stalled on the progress, long story I’ll discuss in my post when I update it. I wanted to go from underneath like you did but couldn’t flip the boat so I went in from the top. Your plywood should be pliable enough to bend and conform to the shap of your outer skin. Just practice with the the blocking and jack until it dry fits just right. You have all the time in the world until you mix the epoxy . Just cover everything under where you are working because there will be drips and it will get messy.