Fixing bulkheads and replacing gunwales on '93 kevlar malecite

[jffdejongh]

I just took the old gunwales off the malecite I bought last fall. There was rot in both ends of the gunwales and I noticed some mouse nest debris in the stern. And that is obviously not sealed
The bow is in great shape

It looks like that the foam is pre-cut and placed in the bulkhead space.

It's there any advantage in trying to 'glassing these to make them air tight? If not, should I try to replace the foam in the stern area in somehow?

The rest of the canoe is in great shape!

 

[MrPoling]

I just took the old gunwales off the malecite I bought last fall. There was rot in both ends of the gunwales and I noticed some mouse nest debris in the stern. And that is obviously not sealed View attachment 139654
The bow is in great shape
View attachment 139655
It looks like that the foam is pre-cut and placed in the bulkhead space.

It's there any advantage in trying to 'glassing these to make them air tight? If not, should I try to replace the foam in the stern area in somehow?

The rest of the canoe is in great shape!

I have a fiberglass Explorer that had similar problems. Mad River must have thought it was okay, and maybe it was for the first 10 years. But once the foam gets damaged water can get down in there.

The first problem with water getting in there is it will add weight after a trip. And it doesn't take much weight in the ends of the canoe to notice it. Second, if the boat got left outside in freezing weather moisture in the foam can cause damage. Finally, it will promote rot and grossness, because moisture will find its way in there, even upside down in the yard.

I cut out all the rotten foam. Then I topped each tank off with spray foam. Once it was dry I shaved it flat and put an ABS cap over it. I used ABS because I had some around, but I think most folks will want to use fiberglass.

The first picture is the canoe brains before the lobotomy. The second picture shows the finished state, with one ABS cap on the inside and one ABS cap on the outside. Normally Mad River covered the whole thing with one big cap.

One of these days I'll make a jig/form so I can bend prettier outer end caps, but for now those do.

 

[jffdejongh]

I have a fiberglass Explorer that had similar problems. Mad River must have thought it was okay, and maybe it was for the first 10 years. But once the foam gets damaged water can get down in there.

The first problem with water getting in there is it will add weight after a trip. And it doesn't take much weight in the ends of the canoe to notice it. Second, if the boat got left outside in freezing weather moisture in the foam can cause damage. Finally, it will promote rot and grossness, because moisture will find its way in there, even upside down in the yard.

I cut out all the rotten foam. Then I topped each tank off with spray foam. Once it was dry I shaved it flat and put an ABS cap over it. I used ABS because I had some around, but I think most folks will want to use fiberglass.

The first picture is the canoe brains before the lobotomy. The second picture shows the finished state, with one ABS cap on the inside and one ABS cap on the outside. Normally Mad River covered the whole thing with one big cap.

One of these days I'll make a jig/form so I can bend prettier outer end caps, but for now those do.

That makes a lot of sense and was kind of what I was thinking. I think I'll cut back the kevlar a little too make it easier to clean out the stern bulkhead. Did you just use regular spray foam from one of the box stores?

 

[MrPoling]

That makes a lot of sense and was kind of what I was thinking. I think I'll cut back the kevlar a little too make it easier to clean out the stern bulkhead. Did you just use regular spray foam from one of the box stores?

I just used spray foam from the big box hardware store.

I'd be inclined to use fiberglass for the covers, I think it'll be easier to sand and clean up after you've glassed. But I don't have experience working with Kevlar, just what I've read on this form about it being more difficult to sand.

 

[goonstroke]

Classic Mad River float tanks sure are great habitat for small furry animals. I don't know what lived in this one I refurbished, probably a squirrel. Great hulls though, well worth the effort.

I ended up removing all the rotten foam and just closing them with fiberglass. There are a few wrinkles, but overall I'm satisfied with how it came out.

 

[jffdejongh]

Classic Mad River float tanks sure are great habitat for small furry animals. I don't know what lived in this one I refurbished, probably a squirrel. Great hulls though, well worth the effort.

I ended up removing all the rotten foam and just closing them with fiberglass. There are a few wrinkles, but overall I'm satisfied with how it came out.

View attachment 139668

That's would certainly save a step if I'm not refilling the bulkhead with more foam.

It also looks like you didn't remake the deck plates. What's the black Velcro looking thing on the top of the bulkhead?

 

[jffdejongh]

I just used spray foam from the big box hardware store.

I'd be inclined to use fiberglass for the covers, I think it'll be easier to sand and clean up after you've glassed. But I don't have experience working with Kevlar, just what I've read on this form about it being more difficult to sand.

How long ago did you die this repair?

I did a little reading and some days the box store stuff isn't great if the skin gets broken because it will absorb water. This makes me mean more towards cleaning out the crusty foam and sealing the end up with glass. (Possibly kevlar too see how hard it is to work with and keep the color consistent).

 

[goonstroke]

That's would certainly save a step if I'm not refilling the bulkhead with more foam.

It also looks like you didn't remake the deck plates. What's the black Velcro looking thing on the top of the bulkhead?

That's a piece of scrap minicell foam I hand cut to make a plug, picture here. When I closed the tanks I left a roughly half inch diameter hole for pressure release. The plugs fit pretty tight so I'm not too worried about them popping out.

I thought a lot about what kind of decks I wanted, and eventually concluded that I don't like decks. I've been happy without any. That hull is fiberglass and pretty thick at the ends, so I'd have to hit something pretty hard to hurt them. The only thing I worry about is my wife's car.

 

[Canoe Trip]

Jffdejongh​

You really don't want to use spray foam that is an open cell foam... You want a closed cell foam. Most of the spray foams at the hardware store (doors / windows / gaps) are open cell foam. Open cell foam will let moisture in and once wet, the rot begins. There is a better spray foam (also made for door / windows / gaps) made by Locktite that is a closed cell foam so water can not get into the foam.​

 

[Cheeseandbeans]

I trimmed the existing foam on my TW Special and glassed over with no decks like Goonstroke.

I can attest to Great Stuff style spray foam absorbing and holding water. I’ve seen it used in some creative auto body repair and you can literally squeeze the water out of it.

You can buy marine specific expanding floatation foam. I believe it is a two part liquid system.

Bob

 

[Canoe Trip]

Yeah you don't want to use "Great Stuff", the stuff is garbage once wet. The Locktite brand is for water tight applications. I'm sure there are other closed cell spray foam brands out there by now - But I know the Locktite brand is closed cell foam.

 

[jffdejongh]

Jffdejongh​

You really don't want to use spray foam that is an open cell foam... You want a closed cell foam. Most of the spray foams at the hardware store (doors / windows / gaps) are open cell foam. Open cell foam will let moisture in and once wet, the rot begins. There is a better spray foam (also made for door / windows / gaps) made by Locktite that is a closed cell foam so water can not get into the foam.​

View attachment 139669

Awesome, thanks.

 

[ppine]

Yes. I had a similar problem with a Sawyer Charger. The nose had been crunched. Not that bad, but bad enough to allow some water into the flotation chamber. I cut away all of the bad fiberglass and pulled out any soft styrofoam. I replaced the foam with a can of new foam and shaped it exactly to the form of the hull. Then laying on the new fiberglass was easy.

 

[goonstroke]

Here's a restore job in this forum that used that 2-part marine foam.

Replacing Floatation in a FG canoe

The Mayfly was made in Austin, Texas around 1975. It is an 18.5 foot, fiberglass canoe with unique "shedding" decks. A foam “bun” had fallen out from beneath the upswept deck. This was likely placed in the canoe as floatation. Fiberglass is heavier than water, so I assume the foam was...

www.canoetripping.net

I'm chicken when it comes to materials with a working time measured in seconds, but I understand it's great when it works.

 

[jffdejongh]

Here's a restore job in this forum that used that 2-part marine foam.

Replacing Floatation in a FG canoe

The Mayfly was made in Austin, Texas around 1975. It is an 18.5 foot, fiberglass canoe with unique "shedding" decks. A foam “bun” had fallen out from beneath the upswept deck. This was likely placed in the canoe as floatation. Fiberglass is heavier than water, so I assume the foam was...

www.canoetripping.net

I'm chicken when it comes to materials with a working time measured in seconds, but I understand it's great when it works.

Thanks!

 

[jffdejongh]

Thanks!

I think I'm going to try the titebond foam canoe trip mentioned above. The bow tank is in good shape and really only needs a little foam added on the sides. The stern needs more foam but I'm pretty sure that the original billet is going to be really hard to get out through the smallish hole at the top. Since I'm sealing the tanks with kevlar on the top.