Seb’s F1 build, Belgium

March 2020:

After having watched Brian’s first episodes, I’ve decided to go for this challenge: building an F1 kayak. I must say the “prep” work was pretty hard: finding the right wood (WRC, green oak) and cutting to length took me several days. Since I don’t own a table saw myself, I bought the wood cut to size from a local specialty wood shop. I then cut the spreader forms from a multiplex board, according to my size.

Before continuing the actual build, I wanted to make the steam-bent coaming ring. I thought it was a good exercise before steam-bending the ribs.  I made it from kiln-dried oak, obtained from the local DIY-store, as I didn’t have access to freshly cut (green) oak. The first try went pretty bad: the strip broke after bending >45°. I therefore decided to soak the planks in water for 5 days before steaming them for 15 min. This helped and I achieved a pretty good coaming:

finished coaming!

Bending the arched deck beams was pretty straightforward though:


April 2020: the hardest part: steam bending the ribs…

After the prep-work was done I finally started assembling the deck. This was really the most enjoyable part: using artificial sinew and wooden dowels it was really cool to connect the deck beams.

Bending the ribs was a bit harder though…As I said previously I didn’t have access to “fresh oak” in my region. I’ve contacted a local lumberyard and they offered me oak planks at €6 each, which I found too expensive. Luckily my father-in-law still had some oak planks from his living room flooring project. I soaked the planks in the bathtub for 2 days:

Yet the results were very dissapointing again after 15min of steaming:

all broken! 🙁

I then took a more radical approach and decided too soak the planks in water for two more weeks. I also decided to use a rigid, aluminum backing strap to reduce elongation in the planks on the outside of the bend:

backing belt with adjustable length
simple steam box: plywood insulated with styrofoam, connected to a wall-paper steamer
The stegosaurus! Ready for bending.

The planks then went in the steam box for about 12 minutes. I put four planks in at 3 min intervals to increase efficiency and to be able to bend all the ribs quickly enough so that I was able to adjust adjacent ribs to make a smooth curve. And voila: by combining sufficient presoaking and using a backing belt I managed to get pretty good bending with air-dried oak.

after finishing the bends I put bricks on top to prevent springback while the ribs were drying.

I immediately added the stringers to make sure the ribs dried in a way that resulted in a smooth curvature.

sewing on the bow plate

I then added the secondary stringer. The video suggest attaching it with woodend dowels, but in this case I decided to simply glue it on (I figured that creating to much holes in the gunwales might compromise its strength):

gluing the secondary stringers

Now I just needed to add the two short back stringers and the single front deck stringer, again using wooden dowels and stringers. I added wooden floorboards, sewn to the ribs.

Be careful if you consider adding these floor boards: they should be thin enough so they don’t touch the fabric, otherwise the skin will stick to it, once you apply the coating (I speak from experience). Also, make sure that the end of the slats do not project beyond the last rib. An overhang could create a lip that can snag your shoes and prevent a quick wet exit! I got this tip from Christopher Cunningham’s excellent book: “building the greenland kayak”.

Assembling the frame was really fun and the video’s were excellent. To protect the frame I applied two layers of boiled linseed oil.

Applying the linseed oil.

honestly… I thought it was a shame to cover it up with fabric… but we do want it in the water, right?

May 2020: skinning and coating the kayak

Skinning

The time has come to cover up that beautiful frame with fabric. I got nylon fabric from Marcin Bober, a friendly kayak-builder in Poland. It’s supposed to have both good strength and shrinking capacity. Purchase (€90) and delivery went smoothly. First the fabric was laid over the frame and roughly cut to size. I then sewed a “pocket” on either side, as in Brian’s videos, sewing it 8cm too short. Together with a partner, I then pulled the rear pocket over the stern to create a good longitudinal stretch.

I then placed a batten under from the back side of the cockpit to the stern, to serve as a guide to make the cut while sewing. Unfortunately, during the sewing proces, the batten had moved a bit off-centre (without my notice) so I had to adjust a little and got an S-shaped sewing line. But oh well, that’s the best proof it’s hand-made 🙂

I decided I wanted a clean center line without pull-holes in the fabric so I used the “welting-cord” technique. If your interested in this technique these are some useful videos:
https://youtu.be/YcvxrXVFESE (Jeff Horton from Kudzu Craft)
https://youtu.be/-bU8Q-TU4Oo (Corey Freedman from the Skinboat school)
https://youtu.be/5U0-PoDuoVA (Nick Schade from Guillemot Kayaks)

Otherwise, Brian’s technique gives excellent results, too, and it probably is a bit easier and quicker to do. I guess it’s a matter of taste.

using straps to sew the coaming in

Coating the kayak:

Before coating the kayak there was another enjoyable step: heat shrinking the fabric. First I sprayed the fabric with clean water, then ironed it two times:

after ironing the skin got drum tight!

Skinning the kayak with nylon has the advantage of being a very strong and durable fabric, with some heat shrinking properties. However the choice of coating materials is limited, since many compounds poorly adhere to it. Brian advices using “Corey’s goop” a two-part coating from skinboats.org. Unfortunately I was unable to obtain this (shipping to Europe would be complicated). I did a bit of research and decided to go for Coelan, which is more readily available in Europe, though very expensive (€55/750ml). It has the advantage of giving a very flexible and UV-resistant result, but it is a very toxic product to work with (always wear a good respirator!). On a next boat I would dare to experiment with cheaper coatings like Epifanes classic boat varnish, though.

I decided not to apply a dye pigment, since I like the transparant “Japanese shoji style”.

the transparent look comes out even better when you place a lamp in the kayak

Carving the greenland paddle

After building the kayak, carving the paddle was a piece of cake. You only need two tools: a jig saw and a block plane. This task is so much more enjoyable if your block-plane is razor sharp. First, the paddle shape is cut from a western red cedar plank. Then, little by little, wood material is removed by planing. This is described clearly in Brian’s video. The result is a lightweight, beautiful paddle. Since cedar is a softwood and the tips get a lot of blows, I decided to coat the tips with a double layer of transparent epoxy to increase the durability of the paddle.

and we have a happy customer! 😉
it floats!

Many thanks to Brian for the excellent instructions, to fellow-SOF-builders for their wise advice and my family for their patience! It was a great journey that I can recommend to everyone!

2 Comments

  1. Avatar
    Matt_The_Carpenter
    August 9, 2020

    Looks great so far! I want to see more!

    Reply
    1. Avatar
      Sebastian
      September 19, 2020

      Thanks Matt! I’ll soon upload some more pictures :=) It’s a fun process!

      Reply

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