Build a Greenland Kayak Part 4




About: skin on frame kayak builder since 1987

This is Instructable number 4 in the Build a Greenland kayak series.
In this Instructable we will be installing the keelson and the stem and stern boards.

Step 1: Materials

In this section we will need a keelson board, 3/4 inches x 1 inch in cross section and 16 feet long. The wood needs to be knot free and straight grained.

A board for making the stem and stern, 3/4 inch x 5-1/2 inch x 8 foot long. Some knots acceptable as long as they are small and tight.

1/4 inch dowel rod 24 inch total length

lashing string (nylon mason's twine)

Step 2: Tools

We will need a saw for cutting and trimming the keelson,
a plane to shape the keelson
a jigsaw and handsaw to cut the stem and stern boards
a drill with a 15/64 bit for drilling dowel holes
a 3/16 inch bit for drilling lashing holes
a wire lashing needle

Step 3: Make the Keelson

Cut the keelson from a 16 foot board that is 3/4 inches thick.
Cut it 1 inch wide.
When you install the keelson, it will sit on one of the 3/4 inch wide edges. In other words, it will be taller than wide.
Plane the corners on one of the 3/4 inch wide edges. The rounded off corners will sit up against the skin. The edge with the unrounded corners will sit on the ribs.

Step 4: Cut Spacers to Shim Up the Keelson

The keelson establishes the line of the kayak's bottom when viewed in profile.
The kayak will be deepest at the bow and get more shallow toward the stern.

With the deck inverted on the saw horses, shim up the keelson so that the distance from the top of the keelson to the bottom of the gunwales is 10 inches at the bow, 7 inches in the middle and 6 inches at the stern.

For spacers, I use sections of two by fours cut to the appropriate length with holes drilled at either end to run the lashing string through.

Install the spacers at deck beams 1, 7 and 11. You will have to do some math to figure out how tall the shims need to be. But assuming that the deck beams and keelson take up two inches of the depth, your spacers should be roughly 4 inches, 5 inches and 8 inches tall.

Step 5: Install the Keelson and Spacers

Lash the spacers to the deck beams and lash the keelson to the spacers.
Check line of the keelson. Rocker, that is curvature of the keelson should be 1 to 2 inches. To measure rocker, set the kayak on the ground, keelson down so the keelson touches ground at the center. Prop up the frame so both ends of the keelson are the same distance from the ground. Measure the clearance off the ground at either end. This is your rocker.

Rocker should be 1 to 2 inches. The straighter the keelson the better your boat will track, but it will also be harder to turn.

You can adjust the curvature of the keelson by re-cutting the spacers or more simply by adding some shims between the spacers and keelson.

Also make sure that your keelson is centered on the deck.

Step 6: Fit Your Stem and Stern Boards

You will be cutting the stem and stern boards from a board that is 5-1/2 inches wide and 8 foot long.

The job of fitting will be easier if you cut the long board in two. However, you don't want to cut it right in the middle because the stem board will need to be longer than the stern board. Hold the board up against the stem to see how much you will need and cut appropriately.

Once you have a manageable size board for your stem, lay it up against the bow and keelson and mark where the underside of the keelson and the bow intersect it.
Trim to your marks and check the fit. Make adjustments as necessary.

Repeat the procedure for the stern. The stern board will be considerably shorter.

Step 7: Dowel the Stem and Stern Boards to the Keelson

Clamp the stem board to the keelson and mark it for four dowels.

Dowels will be 1/4 inch. Dowel holes will be 15/64 inch.

Drill a vertical hole first and dowel that, then drill the remaining angled dowels.

Dowel the stern.

Step 8: Trim and Round the Keelson

Trim off excess keelson in line with the edge of the stem and stern boards.
Use a hand plane to round the corner of the keelson.

Step 9: Drill Lashing Holes for Lashing the Stem and Stern Boards to the Keelson

Drill lashing holes in groups of 3 at the junction of the gunwale and the stem and stern boards.

Try not to drill through any of the dowels that hold the gunwales together.

Step 10: Lash the Stem and Stern Boards to the Gunwales

In triangular lashings you do a few loops on each of two legs of your triangle, then lash around the two legs with a series of half hitches to pull the two legs together and tighten the whole thing up.

Step 11: Round the Corners of the Keelson

Use a plane to round the corners of the keelson at the bow and stern.

Step 12: Stand Back and Admire Your Work

That's it for the keelson and the stem and stern boards.
You are now ready for the next instructable where you install the ribs.



    • Stone Concrete and Cement Contest

      Stone Concrete and Cement Contest
    • Planter Challenge

      Planter Challenge
    • Backyard Contest

      Backyard Contest

    21 Discussions


    2 years ago

    Thank you very much for this instructable!
    I'm building a 1/10 model using your instructions and completed my deck.

    Now installing the stem and stern boards and can't wait to move on to the ribs!

    Thanks again!


    4 years ago on Introduction

    Finished my deck and moving on to the Keelson and Stem/Stern boards. Thanks for the excellent instructable. I am using Western Red Cedar because I am trying to keep the boat as light as possible. The deck seems to be strong enough when everything is doweled and lashed. Thanks again


    4 years ago on Introduction

    First: Thank you for
    the awesome instructions. What a gift to all of us wannabe's
    (soontobee's:). Second: After installing the keelson temporarily I
    could see that the deck is maybe four inches too low for my size 14 feet.
    I'm guessing that lengthening the temporary keelson spacers would make
    the boat too tall and unstable. Can I raise the front deck that much
    without causing other problems?


    7 years ago on Introduction

    how much linseed oil and turpentine/mineral spirits would you mix with 2 ounces of beeswax?
    I decided to make some since I already had all but the beeswax laying around from oil painting. And i found the beeswax at a local health food store called Apple Valley.
    Great Instructable! I got my wood cut today and i'm starting the build tomorrow! :)

    2 replies

    Reply 7 years ago on Introduction

    There's no exact ratio. I would say 10 to 20 % of liquids added to the wax. You can use plain wax. The oil just makes the wax softer and more sticky.


    Reply 7 years ago on Introduction

    i used; 2oz beeswax, 0.25oz mineral spirits, 0.25oz boiled linseed oil. works great. i'm building my steam box today. I'm excited to try bending those ribs soon!


    8 years ago on Step 6

    How thick should the board that you cut the stem and stern boards out of?

    1 reply
    armored bore

    8 years ago on Step 6

    What's the half-round bit in the bow for? To reduce weight or make room for the float bag?

    1 reply

    9 years ago on Step 3

     If I don't have a table saw available can I use a 1x1 (3/4 x 3/4 actual), or should I go with a 1x2 (3/4 x 1 1/2) flat against the ribs?

    Awesome boats you make. I really appreciate your work.

    1 reply

    Reply 9 years ago on Step 3

    a 1-1/2 inch keelson is a little deep and will make your boat less stable.  A 3/4 inch deep keelson is probably a better choice as long as it gives the skin enough clearance from the ribs.


    9 years ago on Introduction

    I would recommend artificial sinew (Tandy Leather) rather than nylon string which is almost impossible to make knot that won't slip and does not lay flat. This then requires you to make "channels" in your wooden parts so that they don't make a bump in the fabric thence creating drag on the wetted surface. These channels then weaken the wooden members by creating starting places for breaks. The artificial sinew likes to lay flat on the surface creating very little bump, kind of like the floss we use in fly tying. Great project and a lot of work you've put into it - nice job!

    1 reply

    Reply 9 years ago on Introduction

    Yeah, I've used that. Nylon string is less than ideal. besides being round, it also stretches when wet. On the other hand, it works well enough. I have used the Tandy artificial sinew. It is pleasant to work with. It lays flat. Being polyester, it does not stretch when wet. But it has low abrasion resistance since all its strands are exposed to the skin at once. After a few years, movement of the skin will sand through it. On the other hand, at some point, you have to do maintenance on the boat and if you decide to replace the skin, that is also a good time to redo the lashings. I used to go paddling at least twice a week so my boats used to get harder wear than they do now when I'm spending more time dinking with new boats than actually paddling them. oh well.


    Reply 11 years ago on Introduction

    What I do is melt some beeswax, add some linseed oil and turpentine and pour it into the bottom of a paper cup. When it cools, I have this hockey puck shaped cake of wax. After you use it a few times and pull string over it and knead it in your hands, it turns potato shaped and dark colored on the outside. The addition of the turpentine and linseed oil to the was make it more sticky. Pulling the string over the wax makes it nonskid so it holds better in lashings and knots.


    Reply 11 years ago on Introduction

    ooooo ok i c now thanx. i cant wait to see the end of this one it looks like its going to turn out great!