Wednesday, December 16, 2009

Progress has been slow the past few weeks due to family commitments, etc.
However the hull is now finished and sanded. The hole in the hull is provision for a viewing panel. Initially I thought of using polycarbonate but at R 1 000.00/m2 - and considering that it will be scratched - I'm thinking of using Perspex.

Sanding the internal curves of the cockpit area is problematic. For the moment I'm using a drum sander on the drill but the surface will have to be smoothed-out manually after glassing (for extra rigidity) due to the inevitable uneven surface that the drum sander creates. (I wonder how busy my wife will be at that time.)

The next step would be the fitting of the external stems and stripping-up the deck. That will have to wait for the new year after our holiday in the Western Cape

My wife and I went out on Durban bay on Sunday between 6am and 9am on our Stealth Supalites in near perfect conditions but I found the absence of an urinal in the kayak absolutely painfull. Something to consider when I design the seat for the wooden Evo. On the other hand, a "Sta-Soft" bottle would suffice, I suppose.

Weight at this stage: 7kg

Hours spent: 70

Monday, November 9, 2009


In this posting:
1. Laying strip, after strip, after strip.
2. Bulges
3. Summer has arrived.
4. Hatch covers.
5. Time is running out.
6. Hours spent so far.

1. Laying strip, after strip, after strip.

Looking at last week's photographs, it is disappointing to see how little progress was made this week-end. The "stripping-up" of the kayak just seems like a never-ending process. However I have covered the worst of the curves that connect the sides and the bottom of the hull and progress should pick up now. But now a new phenomenon reared its ugly head.

2. Bulges.

As the strips of cedar approach the keel line, they are being bent more and more side-ways and this causes bulging between the stations. (The same effect can be seen if you "bend" a strip of paper side-ways on a flat surface). One solution to this problem would be to use stringers but I want to keep the weight down as much as possible. ("Stringer" = a strip of wood glued along the length of the hull on the inside). I then decided to employ cable ties to pull the strips back to an even curve.

I also stopped glueing the strips to the stations and the bulging problem dissapeared to a large extent. I wonder if this is the reason that why the experts don't really use permanent stations?

Cable ties were also used were clamps would just not work

I alway maintain that the person that invented cable ties should be considered for the Nobel Prizes of Peace, Chemistry, Science , Literature and what-ever other categories there are.

3 Summer has arrived.

Summer arrived with a vengence over the week-end and one would think that the affect of the heat on the setting time of the epoxy would speed up the progress. Quite the opposite. The quick-setting epoxy started to set almost immediatle after mixing and I had to stop applying the strips betwee 10 am and 3 pm on Saturday and Sunday. During this time I started to work on the hatch covers.

4. Hatch covers.

A chunck of Tamboti was cut off from the stock and ripped in strips. African Tamboti is extremely hard, fine grained and beautiful. (And very rare and expensive). It is my favourite wood for making trophies and renders a fantastic finish.

The strips of Tamboti will be book-matched.

5. Time is running out

I was hoping to complete the project so that we can take it to the Western Cape during the December break, but with with 5 week-ends left it seems unlikely considering that it needs to be decorated with veneer inlay, glassed etc.

6. Hours spend so far: 58

Monday, November 2, 2009

4. Negotiating the curves

In this posting;

1. Negotiating the curves
2.Steaming Ash
3. Mistakes I made thus far
4. In closing

1. Negotiating the curves

I was naive to think that the glueing of the strips to the bottom would be completed over the week-end.
When I started fitting the strips around the tight curves on the aft section, progress slowed down to a crawling pace.
Imagine a plastic ruler. Twist it lengthwise through almost 90 degrees. Now bend it slightly sideways. Now bend one end downwards in a vertical plane. This is the shape of the strip near the aft section. Sounds easy enough but the bottom edge of the strip also needs to fit snugly on top of the strip previously fitted.
This means that the bottom edge of the strip needs to be planed in a spiral shape. I really need a spoke-planer that the old folks used to plane the inside edges of ox-wagon wheels.

When planing the edges and continiously test-fitting them, my language was far from prestine until I started marking the edge to be planed with white chalk to see what part of the edge still needed to planed.

Due to the awkward shape of the strips additional "dummy bulkheads" had to be made to keep the stips in place.

With each strip to be glued, I had to "dry-fit" the strips by determining which clamp to use where, numbering the clamps and marking the exact position of each clamp on the hull. A tedious process. Only managed to fix four strips the week-end.

2. Steaming Ash

While waiting for the epoxy to set, I started on the external stems. Having played around with steaming wood previously, I quickly built a steaming box and set up a steaming "plant"

After steaming the 6mm thick Ash for 30 minutes, it was quickly clamped to the jig.

It never ceases to amaze me how certain types of wood can be manipulted when steamed. And I love the smell of wood being steamed. Yes, I should have made the curve on the jig more pronounced to lessen the effect of spring-back, but the wood is still flexible enough to be clamped to the right curve with a little pressure.

As an experiment I tried to steam and bend Cedar and this was the result.

3. Mistakes I made thus far:

I should have had twice the number of temporary stations near the aft and fore sections.

I should have concentrated more on utilising the prettier grained wood on the sides of the hull. Now that I'm reaching the bottom of the hull, I notice that the strips that are being used are more colourful than the strips glued to the sides.

Should have bought epoxy solvent to clean off the runs of epoxy after clamping. Unfortunately AMT is closed on Saturdays.

4. In closing:

Obviously the Evolution was never intended or designed to be built in this manner but it does seem feasable provided one is patient and treats the wood and the shape of the Evolution with the respect it deserves.

Monday, October 26, 2009

3. Taking shape

Being a week-end warrior does provide one the opportunity to plan, think and anticipate problems which, in most cases, do not really manifest themselves.
One of my big concerns during the week was; What adhesive/epoxy to use. A brief and productive visit to the friendly people at Advanced Material Technologies (AMT) quickly solved that problem.

I always enjoy visiting these industrial suppliers. They know that you, as a member of the public, won't place a massive order like their normal customers do but their service is always friendly and the advice sensible and informative as opposed to the salesmen of the normal hardware supplier on the corner of the street. (A few days ago, with reference to a certain electrical component, I had to explain to one of these saleswomen what the difference between "male" and "female" is.) I opted to use the AMT A032 clear epoxy for the cedar strips.
The quick-set epoxy is clear and with a tensile strength of 30 Mpa and with adequate penetration when clamped it is good enough for me.

The weather during the week-end was not really suitable for paddling and I managed to make some good progress. Having cut a few strips I joined them with splayed butt joint to the full length of 4m + but when I started gluing the first one in place, I soon realised that it's not going to work. It is extremely difficult to handle a 5mm x 20mm x 4m long strip - especially when using quick-set epoxy.
This may raise some eyebrows: My modus operandi now is to use shorter lengths ( 1.5 to 3m long) and butt-join them on the bulk-heads as I go along. This worked much easier especially when I started negotiating the rather sharp curves near the top of the bulk-heads. Progress slowed down considerably at this point because the edges of the strips need to be splayed carefully with small hand planer to ensure a tight fitting joint, particularly externally.
Had these curves on the bulk-heads been tighter, or the strips thinner and wider, I would not have been able to obtain a fair external curve in these areas afterwards without sanding the strips down to unacceptable thickness.

Having reached the curved section on the hull, the C-clamps had to be discarded (the C-clamps were now too small anyway) and replaced with home-made "clamps" made from rubber tubing that the spear fishermen use on their spear-guns.

I managed to fix six strips on the one side and just had to sand down a section to see how visible the joints between the strips are and whether a fair curve would be obtained without losing too much thickness in the wood.

I am fairly satisfied.
The decorative white strip is Ash which I bought for its excellent steam-bending properties and will be used for the external stems of the hull. It is intended to catch up with laying strips on the other side of the hull during the week to counter stresses that might distort the hull.

A quick word on Western Red Cedar:

We know that this tree is the largest living organism on the planet and with a density of only 340 kg/m3 is one of the lightest woods available for use in construction. In comparison, Beech is 750 kg/m3. (I hope to achieve a total weight of not more than 30kg after glassing.) We were astonished to count 50 growth rings in a 200mm wide strip.
this means that the diameter of these massive trees only increases by 40mm of a 50 year period (less than 1mm per year). I almost feel guilty using the wood but at least we are building a kayak and don't use the wood for making fires.
With the excellent tonal qualities of the wood, the kayak may produce pleasant sounds when paddling over choppy waters.

Total hours spent to date: 28

Monday, October 19, 2009

2. Construction starts

The strong back was built on two doors which were meticulously leveled, lined up and nailed together. Ten stations were cut (using paper templates) from 9mm plywood and fixed to the strong back. Using fishing line on the base it was relatively easy to line up the stations along the centre line and assuring that they were vertical and square relative to the strong back.

It seems that strip canoes are largely built without bulkheads but I don’t have the level of confidence that the experts have and it is the intention that every alternative station remains in the hull as a permanent bulkhead. The seat area between stations 4 and 6 will partly be left open (without strips) as I would like to insert a polycarbonate viewing panel on the bottom of the kayak.

I also notched the stations and glued (epoxy) a 20mm wide Meranti strip along the keel line of the kayak to add stability to the stations and provide fixing areas for the inner fore and aft stems.

I managed to obtain clear (knot-free) Western Red Cedar and cutting it in 5mm thick strips on the band saw proved easier than I thought. The photograph shows the first strip being test-fitted.
Excitement grew as the beautiful shape of the Evolution started to emerge

My methods vary probably from the traditional way of building a strip canoe, but then again the shape of the Evolutions differs quite substantially from the “Canadian canoe” shape.


Thursday, October 15, 2009

1 Introduction

At the age of 10 years I built my first "canoe". The sheet of corrugated iron, with the ends folded over and hammered flat, leaked like a sieve and floated for about 30 seconds before it was sucked down a mild whirlpool in the Orange River which bordered our farm.

"Why build another one?" she asked a few days ago. I looked at my wife. Sometimes she asks these seemingly simple questions for which there are no simple answers.
It's true that I have built three kayaks already (with varying levels of success)
It's true that we already have a Stealth Supalite each. In fact, there's four presently in the family.
And it's true that the list of house maintenance to-do's on the fridge door is growing.

So why build another kayak? I guess the answer is : Why do people climb mountains?

Some months ago I visited Stealth Performance Products to pick a fishing ski. The moment I saw the Stealth Evolution, I got goose bumps. The sleek looking Evolution begs to be hugged, stroked and launched. Reality is that I intend to do offshore fishing and at my age (59) one needs maximum stability. I then settled for a Stealth Supalite - with no regrets.

On a subsequent visit to Stealth Performance Products and mindfull on copyright and ethical issues, I asked Bruce if he would sell me the bottom half of the hull of the Evolution so that I can fit it out with my own decorated wooden deck. Much to my surprise he said:" Why not build the complete Evolution in wood?" When I mentioned this to Mick Clarke ( his encouraging reaction really got me going.

With the support of my wife there's no stopping me now