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Making boats

The workshop has been up and running since July last year and in that time we’ve built three C1s, three Duets and a Demon.

The Duet construction is using vacuum bag from a wet epoxy layup. This has been very successful and we do keep optimising the process as we find better ways to build. The mold has been modified a few times to make the release easier round the gunwale rim, the laminate was curving round and required cutting

The epoxy resin is significantly stronger and stiffer than the polyester and we will reduce the build to two layers for the next boat. By the time the boat is joined down the centre line and the seat support flanges are installed, there is effectively an additional layer anyway, and it’s where the strength is needed. Together with the uni-direction ribs there is a supporting “skeleton”.

The Darkness C1s have all been resin infusion, again with three layers plus the join, ribs, flanges and separate gunwale rim, this is a strong boat. We have also refined the build process as we discover how to better position the composite fabrics, peel ply, distribution media and vacuum film to ensure a more efficient infusion. I still get apprehensive when we open the resin tap, but I never get tired of watching the resin “tsunami” as it wets out the laminate stack.

The picture below shows the different infusion stages and illustrates just how much work there is and the variety of products needed from the gelcoat, through the layup to the vacuum infusion and finished boat.

C1 infusion stages


We have infused one Demon and I have lent it to a crew to paddle the Waterside race series. It has won both Waterside A and Waterside B so far by staggering margins over the next placed Wenonah ICF boat. Being a bit slimmer than a traditional canoe, it is a bit more challenging to paddle in terms of stability and steering, but in the right hands it flies!

There’s a video on YouTube of Waterside A which features some of the Duets in the race, the second place ICF and The Darkness Demon. It is interesting to see the workload of the ICF compared with the Demon crew.

Now I’m in control of boat construction, I’m keen to look at alternative fabrics. To this end, I attended JEC World in Paris, an international composites show and exhibition. It was massive! I spent two days talking composites to likeminded geeks and nerds from some of the most prestigious companies in the industry.

There are so many fabrics and combinations to choose from, plus materials such as integrate peelply/distribution media from Eurocarbon, core materials from Lantor, gel coats from Scott Bader, resins from Wessex Resins, Innegra from Sigma and fabrics from G.Amgeloni to name but a few.

Carbon boat with interesting carbon weave


Carbon fabric samples – 1

Carbon fabric samples – 2

Carbon fabric samples – 3

Carbon fabric samples – 4

Carbon fabric samples – 5


also met with the UK National Composites Centre with whom I’m hoping for some support to test different product combinations. Some of the main suppliers were also interested in a joint venture when I suggested a C1 divided into quarters, each one made with a different laminate stack. This would really show off the versatility of their products.

I start the next Duet on Monday, it’s going to be two layers, one of carbon twill and the second of carbon/innegra, wet layup, vac-bag.

I’ve never been a fan of kevlar, it’s hard to cut, awful to repair, plus it absorbs water and goes brown with age. Turns out that there are some better, modern alternatives such as Innegra, Aramid, and Twaron.

The more I find out about the composite world, the more fascinating I find it. Can’t wait to get stuck in to pre-preg.

Duet – new construction

It’s been an interesting few weeks building boats using epoxy resin and vacuum bagging, we’ve learnt a lot and the quality of the finished product is improving.

I still use a laminate stack of two layers of 200 gram carbon twill sandwiching a layer of 200 gram carbon/kevlar, but the vacuum bag is really forcing the layers together and squeezing out the excess resin. This produces a lighter boat but without the additional polyester resin from the wet layout process, some of the stiffness has been lost.

Rather than simply adding another fabric layer, I have implemented a frame structure within the hull to add strength and stiffness without adding much weight.

The initial design incorporated a gunwale shape which creates a strong rim around the cockpit. This is supported by the three tubular carbon thwarts across the width. Next is the flange which runs along the inside of the cockpit. This supports the cross braces for the seats and footrests. Addition longitudinal rigidity is gained from the carbon tape along the central join.

Duet geometry


Below the flange there is nothing. This was fine using polyester wet layup, but not with Epoxy vac-bag. We don’t want it too stiff because it will break if the boat is dropped or hits an object in the water, so some flexibility is required.

So I took a leaf out of the Wenonah design and implemented a series of ribs.

After a couple of trials on the demo boats, I decided that the optimum number of ribs is twelve, spaced at 300 mm intervals within the cockpit hull area. They are not required beneath the decks as they are stiffened through the design geometry, but they also retain enough flexibility to absorb impacts.

Rib material requirements


I cut out 50 mm strips of Sorix and 100 mm strips of uni-directional carbon fibre. Soric is a core material with hexagonal cells.

Soric core material


The cells do not absorb resin, but the outlines do. This creates a very strong and stiff framework. It really is amazing stuff and I now use it to thicken and stiffen the gunwales, on the seats, and for the ribs. I also use peel-ply to ensure a consistent surface finish.

Material preparation


The ends of the Soric strips finish just under the flange.

Soric measuring and positioning


The uni-directional strips extend beyond the flange, up the side of the hull, but the ends are tidily encapsulated within the flange support.

Uni-directional carbon measuring and positioning


The centre join is formed by a 50 mm strip of carbon/kevlar and a top strip of bi-directional carbon. The ribs are sandwiched between the two thus increasing the strength.

Ribs complete


Once the ribs have gone off, a platform is laid into the hull to support the installation of the flange materials. These comprise of:

Flange materials and design


This right angled flange bonded to the inside of the hull really improves the rigidity of the boat. It tidies up the ends of the ribs and of course supports the footrests and seats.

Flange construction


Coupled with the seat and footrest cross bars, the boat is truly ridged. There is still a little bit of flexibility between the ribs to help absorb impacts.

Cross bracing


The epoxy resin and vacuum bag construction method also improves the quality, but it is massively more expensive than a polyester wet layup.

I also use Soric along the gunwales to thicken, stiffen and strengthen. It doesn’t look as nice because the pattern of the Soric matrix comes through to the surface due to the vacuum pressure, but it is far more efficient and at the end of the day, it is a racing boat.

In summary then, I now have the boat construction I wanted. I believe it uses the best materials in the best way, but in the least quantities. It’s jolly expensive but we diggers are worth it!

First workshop boat

I wanted to setup the workshop properly before I attempted the first boat. I got a whole load of timber for free from a building site, which was destined for the fire, and built the work benches, trestles and racks for the boats. I also bought a number of new power tools and other equipment, plus 20 metres of various carbon and carbon/kevlar fabrics.

As I want to use vacuum bagging and infusion techniques, there is a mass of different materials required, plus resin, hardener, a pump, catch pot and various tubes and valves.

Workshop view 1

I’ve got the floor covered where I’m likely to drop resin. I’ve made an A frame on wheels for all the materials. It can be wheeled out of the way.

Workshop view 2

It’s amazing how much can be squeezed in, and I’ve still got the roof space.

Workshop view 3

We’ve started on the first Duet C2 using Epoxy resin and vacuum bagging.

Duet under vacuum


The place looked quite big until we needed 7 metres of flat surface to cut the fabric for a C2.

Cutting fabric


Obviously we’re learning along the way and next time we’ll use the flanges of the mold for the bagging material and not literally, a bag which measures 7.5 metres x 2 metres.

The point is, I am now in control of if, when but particularly how I make the boats. Before, the boats were made of three layers of carbon-carbon/kevlar-carbon over the whole surface area of the boat. I want to be more targeted and place strength where it’s needed and reduce the weight where it isn’t. I also want to strategically placed core materials for stiffness and strength.

I’ll let you know how I get on.

Setting up production

Up until now, I’ve relied on a boat builder to construct my canoes. Quite honestly I simply did not have the room or facilities to do it myself, plus I’ve learnt so much watching skilled and experienced professionals do the job. This has worked out well whilst I was in full time employment and the demand for boats was slow but steady.

I’ve always fitted the boats out myself, but this involved many hours on my front drive, much to the consternation of the neighbours. It also loses its attraction during the winter months and dark hours.

Demand is increasing, plus I’m bringing out a new model for which I have ideas on how I want to construct it, so quite frankly I have run out of excuses not to setup in-house production.

So I’ve taken out a lease on a unit on a business park and setup a workshop to build the boats myself. It costs £5,500 for a year and I have a three year lease, so I have to hope that people keep wanting my boats.

The new home of DarkSide canoes


This is a big step and I’ve spent a considerable sum getting all the tools and equipment I need plus the materials for the first few boats. I’ve collected my molds and am ready to roll.

The unit has electricity from solar panels on the roof and/or from the grid. The gas is connected to the meter but that’s as far as it goes although the unit has a new (unused) combi boiler and two radiators.

Actually, the bloke before me painted the walls white and installed a whole load of plug sockets.

Key criteria, does the Duet fit?


All the mod-cons.


Instead of using Polyester resin, I plan to use Epoxy and a vacuum bag to compress the layers and force out excess resin.

My plan is to go to resin infusion especially for the C1, and I went on a training course with Dark Matter Composites to learn how to do it. The five day course cost me £1,300 but it was so worth it. They don’t simply show the perfect way to do it because there isn’t one. There are so many options for the type and sequence of composite fabrics. Each one will work, but they all have different structural properties, weights, costs and complexities. Each course group was allocated a laminate combination by pulling numbers from a hat, and we weren’t told how to do it, just the theory. It was fascinating to see how each group approached the task of infusing a model boat, but we learnt so much more by seeing how poor decisions affected the process and the result.

We also used core materials.

The biggest frustration I found was that there is no knowledge base. Loads of people have experimented with resin infusion and a lot of costly mistakes have been made before an acceptable process is defined. This is not necessarily the best way because there maybe something you haven’t tried yet, but it is just too time consuming and expensive to try everything. Why isn’t all this learning captured, documented and made available? The simple reason is that companies do not want to share their intellectual property with competitors, especially due to the investment in developing the techniques. A shame really.

First off we setup test panels. This is where the defined laminate stack is used to determine how far the resin will infuse before it gels. We marked progress every 20 seconds checking both the upside, through the distribution media, and the lower side through the laminate, which was slower. This can be controlled with a pressure dam to allow the underside to catch up before the resin flow reaches the end. (Don’t I sound knowledgeable!)

Test panels


The results of this determines how we approach larger parts and where we position the resin inflows and the vacuum outflows.

Resin inflows and vacuum outflows.


Using the test results, we marked out the part with the resin flow predictions.

This how the infusion SHOULD progress.


It isn’t quite as simple as that because resin infusion finds the path of least resistance and you can get resin flows where you least expect them.

The course covered a lot of other types of composite manufacture including pre-preg, resin film infusion, and even light resin transfer moulding, where we made a male and female mold and injected the resin between them.

So I’m now setup on my own and it control, and luckily I have lots of mates locally who have recently retired and looking for something interesting to do.

The Darkness Demon

I’ve thought of a name for the new boat, “The Darkness Demon”

The Devil in disguise.


It’s been a bit of a devil so far, but it is entirely my fault.

I lent it to some very experienced racing canoeists who soon identified that it is by no means unstable, but due to the bow being slightly off-centre, it veers to the right. I took it back down to my boat builder who applied a big wadge of filler on the bow, and it’s fixed. In the meantime he’s making a new mold.

So I took it to the National Canoe Marathon Championships so that a very experienced lady crew could try it, not to race, but just have a go. There’s a short video, but the most frustrating thing for me was the way they nonchalantly jumped in and pushed off from the side and didn’t even put a paddle blade on the water for stability!

I got some useful feedback regarding the seat configuration, but also a comment whereby the boat isn’t “sit&switch”, it’s just “sit” because it is so directionally stable (goes in a straight line) you rarely need to switch.

As I was at the Nationals to paddle C1 on the Saturday (did I mention I got the silver medal!!), and the C2 event on the Sunday, I persuaded my partner to jump in the front and off we went. Of course there was no problem at all, I feel such a fool.

There was a decent number of entries on the C2 start line, Sarah and I managed seventh out of twelve crews in the Duet, which wasn’t bad as it was only her second outing in a sit&switch,

The National Canoe Marathon Championships 2018 – C2 start – 2


It was a baking hot day but I decided I didn’t need to take any fluid. I threw a bit of a wobbler towards the end and we had to come to the side so I could recover. Fortunately we were able to continue and didn’t lose track position.

As a very experienced racing kayaker and also high-kneeler canoeist, Sarah adapted to sit&switch very quickly. The race environment also contributed to sweeping away any hesitation or doubts, and the boat went well. The switching was infrequent and it allowed me to steer the boat like a “C1” which is what the Duet does best.

I do need to get out in the Demon soon, but it’s just too hot.

Reconfigured C2 and re-test

I just measured the height of the seat flange on the previous prototype, and it was 5.5 cms. This plus the height of the seat is: 5.5 + 5 = 10.5 cms total seat height.

The flange in the latest prototype is 8 cms high. 8 + 5 + 3 cms (seat adjusters) = 15 cms.

No wonder I found it twitchy!

I’ve put the front seat adjusters under the flange and set the rear seat static as far back as it will go. This has reduced the height by 3 cms and the seats are now set at a total height of 12 cms, so I’ll see if that makes any difference.

So, today Saturday 5th May, I emailed my mate Pete to solicit his help in another test. Pete often paddles from Odiham wharf on Saturday so I hijacked his training session.

Pete has decades of single blade paddling under his belt including several C2 and C1 DWs in his Wenonah ICF C2 and J203 C1, so it would be interesting to get his perspective on the boat.

We have never paddled together so we started off with him in the front and me in the back. First thing was his paddle cadence, it is much faster than what I’m used to, but I was soon in sync. Next was his stroke, as a seasoned digger he stacks his hands and draws the blade close to the boat. This caused him to catch the gunwale a few times.

As he was used to switching in sync, he started to call hut just before he switched. This proved extremely useful as I knew when he planned to switch and could adjust my paddling accordingly. I switched with him when it was appropriate but often found myself paddling on the same side in order to steer the boat.

The boat maintains a very straight line so I planned the various bends well in advance, but even so I had to ask Pete to paddle on a certain side to bring it round. I did execute some steering strokes but mostly left it to switching independently from the front.

Pete was rock solid in the boat and would not hear any suggestion of instability!

Over the 4 mile out leg we paused a couple of times but still cruised at 6 mph, 10 minute miles.

We changed round for the return trip. I have very little experience in the front of a C2 but found it much easier, more comfortable and much more stable than the back, it is so like a K2.

This time Pete had to adjust to my cadence and stroke. As I was simply the engine, Pete called hut when he needed me to switch. Again this was useful as it prevented me from trying to steer the boat from the front.

The return leg highlighted some big differences in paddling. I tend to use forward strokes to steer the boat, but Pete was so good at pulling the boat round. I could see a clear change of direction as he pulled the stern round. But it was a bit weird when I was asked to switch when the boat was veering “the wrong way”.

Again, he commented just how stable the boat was and after about 2 miles I was aware of more assertive steering as he hung out over the side and even started edging. No way was I used to all this advanced stuff, John and I just paddle it like a kayak.

During our discussion at the end, Pete suggested that we raise the seat height. This pretty much confirmed something that had been niggling me for the past few months, it’s not the boat which is unstable, It’s me.

C2 – maiden voyage

John and I took the boat out for the first time. We met at Wootton Rivers and put in on the Kennet and Avon canal for the familiar three mile section to Pewsey Wharf.

I mounted the GoPro on a pole and positioned it on the rear deck going out, and the front deck for the return leg.

It was clear when we lowered the boat onto the water and watched it rock, that it had less stability than the Duet but that was expected from the previous prototype tests. We got in and pushed off from the side.

On the water.


Now the thing about John is that he only does full-on training. As he is paddling K1 three days a week at moment, he just dug the paddle in at full power. Although I was expecting this, we still had an instability moment which required a few support strokes, and then we were off.

First thing I realised, was that I had set the seats too high. As the previous prototype had proved quite stable, I got my boat builder to raise the seat flanges 3 cms, and then because I’d implemented a quick seat adjustment method, this raised them a further 2 cms. 5 cms doesn’t seem much, but when it’s close to the limit, it makes quite a difference.

Putting the boat through its paces.


I’d also forgotten how much John moves about in the boat, and it took me some time to relax and let the boat do its thing.

First surprise was how much freeboard there was. When we tested the first prototype, the water level was close to the gunwales, so I build up the decks by 10 cms.

Return leg, more relaxed.


Clearly this has advantages and disadvantages. It means that the boat will support much heavier paddlers than the 2 x 76 kgs of John and me. There is less chance of swamping in rough water especially as the decks are flat. However, there is perhaps a little unnecessary additional weight, the sides are more liable to the effects of wind, and the paddles may have to be lifted a bit higher on the switch. Other benefits include the fact that the spray deck should be clear of even the biggest feet on the footrests.

The boat tracks arrow straight and it is easy to keep it on course. There was an annoying head wind comong in from 10 o’clock which kept [pushing the stern over. I will move the rear seat back a bit to help make steering strokes more affective, not that I was able to get many in due to lack of stability.

The Duet is a devil to turn 180 degrees, but this boat is even worse! John and I are not great at some of the more advanced canoe strokes so about a million sweep strokes later, we brought it round. Not surprising really as it maintains such a straight line.

A couple of K1s tried to ride our wash, but we soon dropped them. I’m not sure that there is much of a ridable wash anyway.

Wash hanging…NOT!


The boat is about 30 seconds per mile quicker than the Duet on the canal and this will become more evident as we get used to it. I will also confirm this by getting other Duet crews to test it. I’d like to see how it performs with a couple of big people.

So, as with all first outings, some things to mull over and some changes to make.

I uploaded a short video to YouTube at: https://www.youtube.com/watch?v=10oTbcl7wH0