Thread: Balsa canoe build

A few more strips are on and the compound curves are starting to appear. The balsa is easy to bend in both directions but getting the bevels right is difficult now.

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Now that the strips are ending along the keel they are being tapered at each end to help stop the curves from increasing.

Tapered strips [800x600].JPG

One strip broke in 2 places and another strip broke after shaping so can't be used now. The strip that broke twice seemed to have done so due to lack of glue in the finger joint. It was saved by applying PVA and clamping up for a while. Overall the glued up pieces have done quite well but continuous lengths would be better.

Broken strip [800x600].jpg

About 6 more strips are needed on each side to close the hull.


As at 25-9-20 [800x600].JPG

It looks like 2 more strips will need to be cut - almost got it right but not quite. At least the bandsaw is still set up so that any new strips cut will be similar thickness to the others.

The hull was closed a week ago and the ends then trimmed to accept cedar stem strips.


Hull closed.jpg



The stems are built up of thin laminations bent with a heat gun. They don't retain the full curve but have enough permanent curve to allow fitment. The first 2 are about 3mm thick, others just under 2mm. Tried a 5mm strip first but the curve was very uneven and would not sit in place without gaps.


The third pic below shows the strip after bending and released.
Stem lam bending 1.JPGStem lam bending 2.JPGStem lam bending 3.JPG

First lamination for each end was glued on using epoxy thickened with WRC sanding dust.

First stem layer on.jpg

I've spent so much time dithering about which glass to buy that by the time I settled on 2oz S glass it was sold out . On the bright side the E glass I bought instead is cheaper and also wider. Thanks to Allan N for checking out the supplier and giving me some feedback.

Some of the resin pack sizes were also sold out but the resin is ordered now as well and should be available early next week.

Sanded the hull exterior yesterday. If this was cedar or paulownia I would have used 60 or 80 grit paper but the softness of balsa had me a bit wary so 120 was used instead. It took a bit over an hour and has come up quite well. Might have got away with 100 grit but I think the 120 was a good choice. I know from bitter experience that a ROS with coarse paper can abrade through a hull in a very short time if care is not taken.

There are a few gaps to fill, some from bad fitting of strips on my part and some from voids in the balsa stock. Also need to do some hand sanding on the stems. Hoping to get some glass on it late next week.

The design images indicated that there was little or no hollow in the ends but there does appear to be a bit. Not sure if it will help with tracking but it certainly won't hurt.

Rough sanded 3 qtr view [800x600].JPG Rough sanded bow view [800x600].JPG

Applied glass to the outside of the hull on Saturday and added some fill coats.

This photo is with 1 run of glass on and shows the extent of overlap. It gives a double layer down the centre of about 380 mm width. The glass conformed reasonably well but I did not try to wrap it around the stems.

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This is with both runs and also with a strip of glass on each stem. At least 1 more layer will be added.
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Interior glassing did not go so well. There were some areas where the glass pulled away from the strips and I ended up having to cut out and replace some large areas. This has always been an issue for me but I think better lighting might be the key. I just could not see the problem areas until after the resin was set and the hull was tilted to do more work on it. So it's not as tidy as hoped but it is done.

Glued on outwales of 8 * 30 mm WRC.
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Glued up deck blanks.
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Cut them to size.

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Cut 54 spacers and sealed the end grain with epoxy.
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Here it is with spacers and decks glued in and the inwales clamped in place ready for glue.
IMG_20210131_123859 [800x600].jpg


Still not sure how to install the seats at this stage. Most info on the net shows them hung from the inwales but my inwales are not exactly robust so I'm thinking some other method would be better. I bought Canoecraft by Ted Moores in the hope that it would have plenty of info on making and installing seats. It actually has nothing about making seats and only shows the standard method for installation. This book is often referred to as the "canoe builder's bible" but after having built a couple of strip kayaks and read up a lot on canoes it turns out to have been no use to me.

That's a nice canoe base.

Thanks Redpen and welcome to the forums.

Finished installing the inwales, sanded the gunnels and decks and then applied 2 coats of epoxy.

P1110005 [800x600].JPG IMG_20210211_212613 [800x600].jpg

Took ages to brush the epoxy onto the gunnels due to the 52 scuppers. I've taken to mixing a batch of about 70 - 80 g, putting the mixing cup in the shed freezer and taking small lots from that (about 10g) to use. It doesn't freeze hard so a glob can be scooped out easily with a stirring stick and it defrosts completely very quickly. This avoids time and material wastage associated with mixing small batches.

Weighs just over 8kg (about 18lb) at this stage.

Hi Labr@

I have just seen your canoe build. Not sure how I’ve not seen it before. It’s looking great!
I started planning my first canoe build a while ago but just haven’t started yet. I think you have reignited my enthusiasm. I have the plans for a Guillemot Nymph.
It’s a small 14ft, light weight single canoe, but I intend to stretch it out to 16ft because I’m a little larger than average [emoji849].
[IMG]https://uploads.tapatalk-cdn.com/20210212/0b0ef891e28cb7d8402df0cec033e749.jpg
This is how the seat is installed in this model.
[/IMG]
I will enjoy following your progress.

Regards

Pete.

Howdy Pete, thanks for that link.

The Nymph is a double paddle canoe, designed to have the paddler sitting on the bottom, hence the low seat. It does show that a seat can be mounted on the bottom so is something to consider - it would just need to have legs in mine to raise it a bit. The front seat could also be on rails for adjustability.

Keep that enthusiasm up - it would be great to see a Nymph build on here.

Regarding materials, the balsa is very light and is strong enough when glassed but is easily damaged before the glassing stage so I don't plan on using it again. Paulownia for the hull with WRC for contrasting gunnels, decks etc is highly recommended.

Just out of interest I saw this YT video on building a light weight foam canoe. At first I was sceptical but the finished result looks quite good and he did a few follow up videos to show it in use.

Been experiencing the joys of wet sanding - at least in my opinion it's a joy compared to dry sanding. Getting there but still a long way to go before varnishing.

IMG_20210311_211548 [800x600].jpg

Going to use 25mm webbing on the seat frames. Frames are ready to attach webbing.
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Bought a 10M roll of Grunt brand polyester webbing from the big green shed. The plan is to use stainless screws to attach it to the frames but a test fit showed that tension would elongate the screw hole in the webbing. Did a test with a coat of varnish on the 20mm at the end and this held quite well. So here are the straps cut for 1 seat waiting for the varnish to dry.
IMG_20210311_212029 [800x600].jpg

I'll need to buy another roll to finish the other seat. If I did both seats with the 10M the straps would be spaced out so much they would be uncomfortable and not look good. It seems that with 30 odd foot of Grunt they would be nothing to crow about .

Also made some rough carry handles. These will go on ropes that run through the decks.
IMG_20210311_211943 [800x600].jpg

Managed to finish the sanding and varnishing, install the seats and attach the carry handles. So at this stage the hull is done and weighs 10.3kg (just nder 23lb). One paddle is complete and the other is an old one that I made as an emergency paddle for the kayaks. The handle was really too thin so it is being beefed up with laminations front and rear. Still need to finish shaping, sanding and oiling it.

IMG_20210327_210815 [800x600].jpg IMG_20210327_211118 [800x600].jpg

Looks beautiful Labr@, well done.
When is her maiden voyage?

Pete.