First Strips

At last I'm laying strips and the boat is
FINALLY getting started!

This weekend I cut all the cedar strips on the table saw using a glue-face blade. Last weekend I tried cutting strips on the bandsaw (less kerf loss), but the finish is too rough for gluing without sanding first. Life's too short for that, so I decided to sacrifice 30% fibre loss to table saw blade kerf. The benefit was that the strips were cut quickly and the edges are smooth. There will be more payoff later too in reduced sanding time.


I also figured out a better way to do the purple-heart inlay. First I build up the basic stripe pattern (red/yellow/red etc), then sandwich those strips with purple-heart, and cut the whole works with the bandsaw. I'm free-handing the curve as I cut.




Here are the built-up strips. Once each strip is assembled it goes onto the form and is edge-glued to the adjacent piece.






I am using two clamping methods here.

The first is very fine fishing line which is pull tight around the newly glued piece, wrapped around the shearline brace and clamped with spring-clamps. The benefit is that as soon as one row is glued, the next can be laid up and glued. When the glue is dry, it is easy to pull the fishing line thru and reuse it in a new location.

The second clamp is the combo rubber-band / bull-clip (heavy-duty office paper clip). These are exerting a downward force on the strips to keep them tight against the form.

Test Strips

This was a test of the strip inlay method, and for cutting strips on the bandsaw. While I was happy with the 'look', I was not happy with the quality of the strips, nor the finickiness of fitting for each individual piece in this puzzle.

This effort is likely to end up in the fire-pit. Some days are productive, some aren't.

Finishing the Strong Back

Here's the finished strong back, but first....

All the forms got positioned, squared up, and braced with blocking. Then I installed the Shear Line Bracing using an air-driven stapler with 3/4" staples.






The next step was to sand down the shoulder that was created by a 'squared off' shearline brace intersecting with the rounded edge between the top deck and the hull. This was easy to do with a belt sander and following the curve of the top deck. Then I glued the shear line bracing at the bow and stern and finished shaping these with the sander.

This is the bow....











...and here's the stern.








Later, a black bear stopped by to check out my boat, although Rick said he was really checking out the BMW.

: )

Setting Up the Strong Back

Building the strong back consists of two parts: making the strong back, the beam on which the forms are mounted; and making the support, which keeps the strong back aligned and solid during construction.

The support consists of 6 inverted T's each made of two layers of 3/4" G1S plywood sandwiching 3/4" Baltic birch in the base, for receiving threaded 1/4" inserts and plastic feet, and a gap at the top where an L will be mounted and height adjusted for receiving the strong back. The adjustment is necessary because the strong back varies in depth from 3", to 4" to 5" and back to 3" as it goes down the boat. As long as the support is rigid and close to being aligned, the fine-tune adjustments can be made with the L pieces as shown below.

The longitudinal and vertical position of the T's are held by 2x6's which are lag-bolted (not shown) and bolted thru with ready-rod.


Here I am fine-tuning the position of an L seat. The red dot is from my laser level to ensure that all the L's were vertically adjusted correctly. The string aligns all the L's down the length of the support. and the spirit level is used to make sure that the seat of the L is parallel with the ground. As each one was set in true position, I clamped it with a spring clamp, then screwed it twice from each side of the support.


Here is the completed support with the L's set as required to receive the strong back with the boat in the upright position.

Note that it is common to build kayaks making the hull first, therefore mounting the strong back upside-down initially. I have a reason to build the top decks first, which I will get into later when we get to that part.

Then, it's a matter of building up the beam portion of the strong back, and sliding the forms on at their 6" intervals. A trick is to rub floor wax generously on the beam to help ease the tight-fitting forms along. I know I broke a couple of forms in my first project. I didn't break any this time. Either I'm more patient now or perhaps just wiser. I'll credit the Baltic Birch.


So, after a 13-hour day, the forms are on the strong back and the whole affair is sitting on a rigid support. Note that the 26ft long boat is fitting diagonally across 2 bays of our carport. This was a great compromise because it left room for Rick to park his BMW motor bike, AND the entire length of my boat is under cover! (see pic below!)

This photo also shows my first boat hanging in the rafters, and the form for it up on a rack on the wall to the right. Hopefully I'll get "My Escape" into the water soon so I can row while the new boat is getting built.



Whew! Just fits! But, not finished the form yet. Each station has to be checked and secured, than the Shearline bracing goes on. Lots to do yet....

Shearline Bracing

I have decided to install a 1/4" x 3/4" strip along the shearline. Because I intend to use a non-linear layup of strips, I'm going to need somewhere to clamp the strips to when they land between form stations. To do this I needed to scribe and then cut out a notch for the strip on each form.















Here you can see how the shearline bracing starts to define the shape of the boat.

Tiny form!

Cutting the Forms

The first step in transferring the patterns to wood is to check that your photocopier isn't stretching the image. Once I found a copier that was true, I made a copy of the drawing for every form (52 in total).

This time I used 8.5"x11" sticky back labels on Baltic Birch plywood, rather than gluing the forms onto G1S (good one side) plywood. Baltic Birch plywood has very thin laminations that are thoroughly bonded, and the surface is very smooth on both sides. It is sold in 60"x 60" sheets. I purchased 3/8" for the forms and 3/4" for the strong-back. My experience so far is proving that this product is superior to structural plywood by far, and is well worth the cost, especially if you intend to use your form more than once.

Using a bandsaw for cutting out the forms was sheer luxury after the jigsaw method of my last project.

Finally I have all the bow and stern sections cut out. There is something very satisfying about seeing all the forms line up like this!
The end form protrudes from the center of what will become the strongback. I formed the V in the bottom with a power plane, but a belt sander works just as well, especially on Baltic Birch.

Design Stage

I redrew the bow and stern sections making the boat with 10% higher volume than the prototype. I hope this doesn't prove to be a mistake, as I am also decreasing the weight of the boat. Later I added the curve to the top of the bow and stern decks, and changed the shape of the forms after 25'-6".

I want the woodwork on the deck to get away from the long straight lines of the boat by creating the illusion of depth and motion.



I like the idea of a twisted ribbon: red cedar on one side, stripped red/yellow on the other, over a yellow cedar background, twisting loosely around a thin meandering strip of dark hardwood. This is drawn out in full scale on freezer paper.

The method for building this top deck will stray very far from normal strip-kayak building. The decks are each about 10ft long and about 12" at one end, tapering to nothing at the other. I'm hoping I've solved the problem I had last time with glassing the inner seam where the deck meets the hull. It is extremely difficult to reach into a 10ft long tube!


The next big challenge is the rowing deck itself. In my effort to make the boat both light and stiff, I am going to cast the deck in carbon fibre and embed attachments for the rowing hardware. For this I will need to make a form that will look something like this, shown in negative shape and upside down.