Refinishing Unglassed Furesø wood canoe

[Sabs]

Hi everyone, I hope someone can help. I just bought an unglassed wood canoe that has been out of the water for at least two years.

It will need a new coat of spar varnish and a soak to re hydrate the wood and seal the gaps. But which comes first? Varnish or water? And how long do I soak it for? Is there any way to know the soak is done or it’s done when it stops taking on water?

Also before someone suggests it, I’m not interested in glassing or canvassing the hull.

Some pictures to show her off. I’ll be adding a tent to it later too.

Thanks for the help.

Sabs

 

[Jim Dodd]

Well ? If you varnish first ? I wouldn't think the wood, would swell as much.
My vote ? Soak first, then Oil, not varnish.

Maybe do a little research into the Rushton canoes, and how they were finished.

Very cool canoe !

Jim

 

[Robin]

I think you would find more help over at the Wooden Canoe Heritage Association website, (wcha.org) for the information you are looking for.
Nice canoe.

 

[Cheeseandbeans]

Beautiful canoe. I have heard from several builders that swelling the wood with water is not the way to go. Tightening the gaps and sealing with a "boat soup" sealer is preferred and will add to the longevity. An example of this technique is explained by Geoffrey Burke in the link below. I agree with Robin- post this on WCHA. Best of luck- that canoe really is stunning.

Bob

 

[yellowcanoe]

Geoff is the go to guy around here for all wood boats. It's how he makes his living and has for a long time. He has built some gorgeous ones.

 

[Glenn MacGrady]

Beautiful canoe. I have heard from several builders that swelling the wood with water is not the way to go. Tightening the gaps and sealing with a "boat soup" sealer is preferred and will add to the longevity. An example of this technique is explained by Geoffrey Burke in the link below. I agree with Robin- post this on WCHA. Best of luck- that canoe really is stunning.

Bob

I don't own or work on wooden boats, but that video by Geoffrey Burke was very interesting and seems to provide the definitive procedure for stopping leaks on all-wood boats.

 

[Jim Dodd]

The Boat soup as he calls it, acts a lot like Watco .
Great video !

 

[Sabs]

Thanks everyone for the suggestions and kind words!

I'll check out this boat soup idea. I had to transport it in the rain yesterday and it got wet enough that I could push some water out of the seams of the strips, so it will definitely need some finish on it.

@Jim Dodd there's already some finish on it, not sure what it is, but by oil, do you mean like a boiled linseed? or just an oil based spar varnish? I wasn't going to use water based or polyurethane.

I'm also a bit in doubt of the wood species. I've narrowed it down to either Mahogany or Teak. It was built in Denmark so either is possible, but hard to tell under the finish. I guess the smell will tell after I sand it, since there are some loose/bubbled areas of finish by the stem.

Sabs

 

[Cheeseandbeans]

Closing the gaps is what is going to keep the water out. Is there a local wooden boat builder local to you that could offer advice or help with the woodworking piece?

Bob

 

[Sabs]

Closing the gaps is what is going to keep the water out. Is there a local wooden boat builder local to you that could offer advice or help with the woodworking piece?

Bob

Spoke to a local place today. He confirmed that the boat was built in the 70s out of mahogany, and that in fact these boats were built with a cotton string between each strip to help keep the boats water tight. He suggested soaking for a week, then putting on a varnish that was the "most chemically vial smelling thing" I could find. Needless to say he was not a fan of water based varnished.

He was hesitant about the boat soup idea, mostly because he though sanding the inside of the boat was a waste of time, he didn't think the soup would seep into the crevasses of a 50 year old boat with who knows how many layers of varnish inside.

But now I am at a point where I have conflicting info, so more research is needed.

Sabs

 

[Glenn MacGrady]

But now I am at a point where I have conflicting info, so more research is needed.

I don't sense the info is conflicting. It's more like the guy in Denmark simply doesn't have experience with the process recommended by Geoffrey Burke. If you are going to ultimately varnish the boat, how can it possibly "hurt" to sand, then soak with boat soup, and then varnish. At worst, the sanding and boat soup simply won't help. That's how I'd look at it, rather than as a conflict.

And remember, Burke strongly emphasized re-tightening the clench nails and rivets first.

 

[Sabs]

I don't sense the info is conflicting. It's more like the guy in Denmark simply doesn't have experience with the process recommended by Geoffrey Burke. If you are going to ultimately varnish the boat, how can it possibly "hurt" to sand, then soak with boat soup, and then varnish. At worst, the sanding and boat soup simply won't help. That's how I'd look at it, rather than as a conflict.

And remember, Burke strongly emphasized re-tightening the clench nails and rivets first.

the conflicting info is about whether or not to soak the boat. The Danish boat repair guy said to soak it, then refinish, and Burke says to flood it with thinned out Spar varnish. I'd say those are opposing views. And while he may not have experience with the soup process, he has experience with these particular boats, since he is a third generation boat builder.

I think what could hurt is if I set the place on fire with the tung oil rags, but seriously, the issue could be that if I do this boat soup method, and it soaks into the wood as intended, but there are still gaps, then I've eaten it, because the water soaking method will no longer be an option since all the gaps will be half filled with dry oil and urethane. And I can't sand it off, as he mentions in the video, it's in the shadow of the finish.

I know he emphasised the re tightening of the fasteners, but not only do I not know if thats how this boat is built, but more importantly, I don't know if I can properly tighten thousands of these things with the skill Burke has. He is after all a master of the craft, and I am not.

sabs

 

[Glenn MacGrady]

the conflicting info is about whether or not to soak the boat.

I'm confused by the concept of water soaking. Burke does say to clean and wash thoroughly with water, but then to let the wood dry for several days before sanding, souping and varnishing.

Are you saying that a recommended procedure is to soak the hull and then apply varnish while the water is still in the wood? That would be a conflict. But if soaking is followed by drying, then there is no conflict about the soaking part of the procedure.

Some searching reveals that soaking is a method to re-swell a wooden hull, intended to be moored in water and to be permanently wet, such as a cabin cruiser or other large boat, if you are re-launching that kind of wood hull after it has been removed from the water for a while and dried out. However, a wood canoe is not intended to be moored permanently in the water and to have a permanently water-swollen wood hull. It spends the majority of its life on land, dried out. I don't see how soaking a canoe to re-swell the wood every time you want to launch it is a practical procedure.

A canoe, it seems to me, should be sealed against water entry whether it is in the water or out. "Damming up" the crevices between the wood strips would seem to me to be the only practical procedure. Tightening, boat soup, and varnishing (plus cotton strings in the crevices) seem to be a logical process to dam up the crevices. Soaking would seem to be just a temporary swell mechanism until the wood strips unswell again when the canoe dries out on land in a few days.

I guess I'm just confused as to why water soaking, by itself, would result in a long-term leak proofing of the crevices between the wood strips of an open canoe.

 

[Boatman53]

I’m in the clean it, boat soup, and varnish. Long time friend of Geoff, he knows his stuff. I dealt with the same issue as your boat built with the same method, it is the way to go. Speaking from 35 years professional boatbuilding.
Jim

 

[Sabs]

So I should mention that here in Denmark it is common (as this boat will be as well) to moor it in the harbour over the summer. I tried to get a spot for it at my canoe club but they said they wouldn't have a spot for it for two years.


In my mind, the soaking of the boat and drying of about 3 days will increase the moisture content of the wood, but is not enough to make it bone dry. Like when making furniture, you are looking for very dry wood to maintain dimensional stability. If you use wood that has too high moisture content, it will warp as it lives in your dry house. But the boat lives on the water, so it will need a higher relative moisture content, which will be reduced if you store your boat dry for 11.5 months of the year.

I've read some posts on the wcha website where some have said that after they souped the boat and launched it, the wood swelled anyway and then they got oil and varnish gum squeezed out through the seams which are now raised hard bumps, and their boat still takes on water.

I guess I'm just nervous to mess it up because it seems like a one way street with boat soup.

But I will trust the knowledge in this space and give it a go!

Sabs

 

[Glenn MacGrady]

This is such a lovely and interesting canoe. I've never seen such a construction or heard about canoeing in Denmark. So I'm curious about some things.

I know he emphasised the re tightening of the fasteners, but not only do I not know if thats how this boat is built

It's not lapstrake construction. Can you see nail heads on the outside of the hull or clenched nails on the inside? Or rivets? I can't quite tell from the photos.

So I should mention that here in Denmark it is common (as this boat will be as well) to moor it in the harbour over the summer.

I didn't realize this. Will you paddle mostly in salt water or fresh water or both?

I guess I'm just nervous to mess it up because it seems like a one way street with boat soup.

Understandable to be nervous undertaking new ventures. I'm not sure we ever determined whether the canoe leaks now. Does it? If not, maybe all of this can be postponed.

 

[Sabs]

This is such a lovely and interesting canoe. I've never seen such a construction or heard about canoeing in Denmark. So I'm curious about some things.



It's not lapstrake construction. Can you see nail heads on the outside of the hull or clenched nails on the inside? Or rivets? I can't quite tell from the photos.



I didn't realize this. Will you paddle mostly in salt water or fresh water or both?



Understandable to be nervous undertaking new ventures. I'm not sure we ever determined whether the canoe leaks now. Does it? If not, maybe all of this can be postponed.

Hi Glenn,

I haven’t had it in the water yet, my mooring point hasn’t been approved by the municipality yet, it’s not lapstrake, just butted. I was thinking the same about wait and see, but it needs new varnish anyway. I can see some cracks between the strips so I think it’s best to start here.

I can see that it’s copper nails, but I’m going to my friend’s barn after work to wash it and then I’ll take some close up pictures.

I’ll mainly be on a freshwater lake with this but we can paddle in the canal too which is salt water but it’s not very salty.

I’ve found a video from tips from a shipwright where he is installing cotton between the joints of a larger wood boat. I assume this is also how these boats are made.

Sabs

 

[Boatman53]

I would think the planking is too thin to caulk like that. Close ups will help with advise,but are you sure they are just but joints? All the ones I’ve seen that are similar in appearance to yours had angled joints or overlaps.
Jim

 

[Sabs]

I washed the boat today. It is definitely butt joints. There is an area near the bow were you can see light coming through a gap. I tired to get a picture but it wouldn't turn out.

There's also some sealing in the gaps that is crumbling a bit like old rubber. In another video from the video series I shared, he shows that after he caulks with the cotton, he uses some flexible putty to fill the joint flush and smooth. The can is labeled "seam compound". He says it's sandable and takes years to dry fully. I assume this also has something like this.

This is the bow, you can see some flaking of the varnish, and the light lines of the filler in the gaps, as well as the dark areas where it has been exposed to the elements.




The stern has similar gaps and some loose varnish.



There are also two areas of some discolouration like this. It's not as dark as this image shows in real life.


There is some raw wood and damage at the bow. (Ignore the spider eggs). The rectangular hole there is a brass insert for the tent. They are all along the gunwale.


Some gaps to fill at the bow to tighten it up.


Some more raw wood at the stern. (I guess someone was learning how to steer)


Clearly a nailed construction with no rivets. Interestingly the inner strip of wood running the keel line is pine. Not sure if this was a repair or done like this originally, but I'm not about to tear it out.


And here's the boat after we washed the inside, before we washed the outside. You can see the seams have swollen and the rubber like filler inside. It crumbles if you pick at it. It feels like a running track surface. Not sure if I should maybe try to pick some of this out and re fill it. I think I'd need to take it down to the wood for that though.


So, Step 1 is done. Next I guess it's hammering all those nails. Though I am a bit hesitant to do that. It's one thing to hammer a raised rivet in a vice and quite another to hit a flush nail on the underside of a 3ft wide mahogany boat. I'm worried I'm just going to end up denting the whole thing and making it look like garbage each time I blindly swing the hammer at the underside of the boat.

If anyone has a tip for how to hold a piece of iron on the inside of the boat while it's upside down though, I'm all ears. Maybe I just focus on the areas that have exposed seams though.

Also, is it worth removing the keel banding before boat soup and varnish or can that just stay on the whole time?


Sabs

 

[Glenn MacGrady]

Very interesting. I have no experience to offer, but as to this . . .

If anyone has a tip for how to hold a piece of iron on the inside of the boat while it's upside down though, I'm all ears.

. . . unless there is some special tool or jig or clever trick available, maybe you need two people for the hard-to-reach nails—an iron holder and a hammer tapper.