Made the first trialling of my kayak today, a short 10 km paddling just to verify if everything works! All goes smoothly, hurray! The solar panel is adding juice to the battery, could see that obviously since the lights have become more intense, and pump has become much stronger (I almost used up the battery the day before). Under this tropical sun, that wouldn’t be a hard task for the solar cells, I guess!

The rudder works nicely, the pedals could be easily kicked by my legs, changing direction instantly. The pedals movements could be improved however, to become lighter and more responsive. Every parts of the boat simply just work! And the paddles also, I’m feeling pleased with the new paddles. And for the main part, the boat itself… it feel just a bit more stable (that’s what I was expecting for), but the hull now tracks much better!

It could go quite straight even without the rudder deployed. The feeling that the shorter boat is very steady, and could possibly go faster compared to my previous Serene – 1 kayak. Though the LOA (length over all) of Serene – 2 is shorter, its LWL (length waterline) is pretty much the same. The higher free board makes climbing into the boat a bit more difficult, but that’s not a problem, cause the cockpit now is a bit larger.

The slightly higher free board is very important, it should keep water out of the deck for many of the times, and hence waves shouldn’t threaten flooding the hatches much. My overall feeling is very pleasing, for those months of efforts put into the watercraft! But 10 km is too short, I need to trial the new kayak more, and record the routes by my Garmin, to really evaluate the boat’s performances in precise numbers.

Sticking the vinyl decal decorations is among the last steps that complete the kayak. Since the deck spaces are almost used up for various accessories, the boat names and owner’s informations go onto the port and starboard sides instead, and the boat eyes intrinsic for any Vietnamese boat of course! The solar panel is tied on the aft deck, stretched with two short wooden spars, and lines through its grommets.

There’re some more items to be built or fitted for this kayak: the seat, the carriage for transporting the boat. I would rebuild my previous carriage, reuse the 2 wheels, but build it lighter and smaller, to easier carry it on the aft deck. The seat and back rest are also important parts, but those would be postponed to a later phase of the project. Also, I’m still waiting for my spray skirt to be shipped from Amazon.

After sticking the vinyl decal decorations, the bottom receives additional 2 layers of transparent PU paint, making them 3 layers in total for the bottom (the deck only received 2 layers), protecting the vinyls. The handle line pulling through a hole drilled at the bow (with a wooden block inside) is just a simple hang – man knot, the kayak has no handle at the stern, since the rudder has taken up all the space.

It’s so good a feeling to see the boat completed! Looking back on the building progress, there’re still things that I’m not really pleased with, in building quality, in the look & feel, in equipments… But I believe this is my best boat so far, accommodating various small design changes that I’ve found neccessary from my paddling experiences. I should start trialling the kayak soon, to see how she would behave on water!

Rectified one problem with the signal light, the bulb is too greedy, it eats up a lot of electricity and could potentially burn up the reed switch (I’ve noticed the reed switch has malfunctioned sometimes due to the high current). So I replace the bulb with 8 small white LEDs (1 Watt each). Some more soldering work, but finally it’s done, equally bright, but less power consumed, and safer for the switch.

Today, I installed and tested the rudder system. First is the two cable lines used to pull the rudder up and down. The 2 lines run back to the cockpit and are attached to 2 small wooden balls, with a short segment of bungee cord. Third image: the wooden balls and bungee cord. The bungee serves as a shock cord, in case the rudder should collide with some thing and kicked back, so that no damage would be done to the whole system.

One simple rule to operate the pull up / down lines: grab the ball that is further from the cockpit and pull it. Well, it sounds pretty simple, but useful enough, when in action, you just don’t have to think over and over again: which line is up, and which line is down! The two rudder control lines run back to inside the cockpit where they’re attached to the pedals via 2 small wooden jam cleats to adjust the lines’ tension.

All works well, but the pedal motions are not really smooth, because the bungee cords are not strong enough to pull the pedals back (once one pedal is kicked, I would just have to kick the other pedal to balance the rudder). But I would just leave them as they are for now, as they’re working already, would consider replacing the bungees with stronger ones (or revise the design a bit) later on.

After joining the hull and deck, the hull receives its final bottom glassing. The fiber fabric would overlap the deck about an inch, to better seal the joint. One little trick to make a clean, tidy line at the painting (or epoxy) boundary: mask the area to paint (or to fill with epoxy) with duct tape. Prior to applying (colored) paint or epoxy, brush the duct tape with a very thin layer of transparent paint (or epoxy).

Wait for the paint (or epoxy) to cure, than apply the (colored) paint (or epoxy). That way, the colored paint (or epoxy) won’t leak through the duct tape, cause no matter how good the duct tape is, paint (or epoxy) would leak through, causing a blurry, untidy line. Second image: masking with duct tape, prepare for glassing the hull. I run out of my fiberglass fabric roll after this task, also use up the last drop of epoxy!

The hull glassing receives an additional layer of fill coat, then another layer of epoxy at the 3 seams, then a slight sanding. I don’t sand much, just at some rough places. The color scheme for this kayak is also brown / yellow like my previous two boats, but this time, the colors would be much lighter. Next would goes in the vinyl decal decorations, then varnishing the whole hull and deck with transparent PU paint.

Since the deck’s space is used up for the 3 hatches, the bungee cords, the signal light and solar panel, and other accessories, all decorations would go to port and starboard sides: the boat eyes, boat name, and owner’s information! There’re many many other unnamed tasks required still to finish the boat, so I won’t hope to complete it until next week. However, the kayak would see water and start its trial paddling very soon!

It’s time to join the hull and deck, and now the boat takes its final shape! The gunwales are bevelled differently along their length to better accommodate the deck, paste some putty on the bevelled edges, then I press the hull and deck together, like the two halves of a peanut shell. Everything goes on quite smoothly, the bow and aft parts fit very well, just use some duct tapes to press them together.

In the middle part, there are some small gaps (about 3, 4 millimeters), so I need to fasten them with some cables. The bulkheads fit really well, firmly holding the deck and hull. To maximize the boat waterproof capability, I carefully fill the internal seams with some more putty at places which are still accessible by my arms. The whole thing is left overnight for the putty to set, permanently forming the boat shape!

The next morning, I carefully trim the deck part. Since the deck is cut oversized, it’s slightly larger than the hull, it need to be trimmed down to match the hull, apply some more putty here and there to fill some remaining gaps, then round the seams (the external sides) in preparation for glassing the hull. Months of preparation, consideration and hard works has finally “culminated” into a seeable, touchable object!

It seems that, at this point, the boat would be able to see water in no time. But actually, there’re lots of works ahead: glassing the hull, install the rudder, rudder control lines and pedals, fitting the bilge pump and signal light, sticking the vinyl decorations (text and boat eyes), fitting the compass and all those bungee cords, various other accessories, etc… and finally varnishing the whole thing with transparent PU paint.

Finished all electrical wiring and device testing. It looks simple, but actually, for me, there were lots of works. First is to figure out how the relay pins work. First image: I noted down the wiring diagram of a relay, the 2 pins on the right, one is NO (normally opened) and one is NC (normally closed). The middle pin on the left (the common pin) supplies power to the targeted devices (here is the compass light, just for testing).

The two other pins supply power to the relay itself, when powered on (decided by the reed switch), the relay switches from NC to NO position, hence supplying power to the compass light. All wirings runs back to a central point: the plastic waterproof wiring box, which houses the battery, the solar charge controller, the relay… It took me some times to install all in the box, connect the correct wires, check if everything works!

The PowerFilm solar panel shipped with a long water proof detachable cable, so I run the cable from the central compartment to further aft where the solar panel would be located. This cable runs through a cable gland to exit the deck, ended with a waterproof connecter. It’s not very nice to always have this connector on deck, but it’s convenient to disconnect the solar panel and stored away when it’s not in need.

There would be another waterproof box (connected to this wiring box which would be rarely opened) which houses the 12V – to – USB and the 12V – to – AA charger, which could be usually opened to put your various devices in for charging (iPhone, VHF radio…) But that would be in another later phase of the project. It now time to joint the hull and deck parts together to form the final boat shape!

Next is running the electric wires. I want them to be completely waterproof, so every wire running is placed inside plastic tubes for additional protection. First image: I solder 3 reed switches with wires, place them inside the small wooden bar, seal it completely with epoxy, and glue them under deck inside the cockpit. The letters C, P, L mark the positions of the switches for: compass, pump and light.

All wiring runs back to the day hatch, where a central box housing the main battery. I just use a LOCK & LOCK plastic box, it’s pretty much very watertight, if you close it properly. All wiring tubes would be connected to the box through cable glands with silicone glue. Another issue solved is the relay, it took me an hour to figure out how the PCB relay wiring works! Luckily, I haven’t forgotten all electric knowledges learnt in college!

Since the reed switch is so tiny, it usually can’t stand the amplitude of the current required by the bilge pump. So the reed switch is used to activate another switch (the relay), which can handle the current (it’s so good a feeling to hear a small ‘click, click’ sound when the relay is activated / deactivated) The electrical, electronic parts of the project is not as hard as I’ve expected, all is done quite neatly!

Today, most equipments I ordered from Amazon has arrived: the PowerFilm 7W rollable solar panel, the SunGuard 4.5 Amp solar charge controller, the Rule 500 GPH (gallon per hour) bilge pump, a marine signal light, one Stohlquist “high – back” PFD… and some other things. I was feeling very good, as this phase of the project could be completed soon, and the boat is already somewhat quite near its completion!

Now working on the electrical parts of the project. From other renowned sea kayakers, I’ve long learnt about their electrical and electronic system. And my own experiences pointed out that, the need for a battery system to run a bilge pump (and to power various other devices) is very urgent and obvious. From the very early phases of this project, I’ve been thinking over and over again about it.

The system would have a solar panel, to charge into a SLD (sealed lead acid) battery. The battery is used to power the bilge pump, its primary purpose. But since now I have a 12V DC electric system onboard, I could use it to: illuminate the boat’s compass, power the signal light, and to charge various electronic devices: the iPhone, the VHF radio, the Garmin, cameras, etc… Basically, I want an independent system that power all.

First is the compass light, some white LED sources to illuminate the compass in case of paddling at night. I could just buy a compass with built – in lighting, but those such compasses are not readily available in the local market, and usually they’re a bit oversized for a tiny boat like Serene – 2. So I decided to modify my current compass to accommodate 4 white LED bulbs, the result is beautiful (1^st & 2^nd image)!

The most special thing in my electrical system is… the reed switch, a sealed electric switch which could be activated by a small piece of magnet (3^rd image). That way, the switches could be hide and sealed inside the hull, completely covered in epoxy to protect them from water, and they could be turned on / off by the presence of some small pieces of magnet outside of the hull. I’ve found the idea… simply brilliant!

The deck is stained in a light – yellow color, compared to my previous boats, this kayak would receive a much lighter color scheme. Light, bright color would reveal more the defects on plywood and my building mistakes, but I don’t really care about that anymore, as soon as the faults are not too obvious. Then a thin layer of glass throughout the deck (first image). Next comes various deck fittings.

First are the cleats used to tie down the hatches’ lids. These wooden cleats are glued on, then bolted down with 2 small bolts for each cleats. I carefully fill the bolts’ holes with epoxy, then paint the internal side with some epoxy to prevent water leaking in. Tying down the hatches’ lids with lines is not a very handy way, but it’s simple and very secured, compared to other complex locking mechanisms.

Last image: the rudder control lines’ tubes exit the deck near the stern, secured by 2 small wooden blocks, and protected by 2 cable glands to make the deck completely watertight. On the other ends of the tubes are similar cable glands inside the cockpit. I also made 2 “double – ended” wooden cleats to micro – adjust the rudder control lines’ tension. Various other wooden parts are also fitted on the deck.

The progress slows down as I approach one of the last major phase of the project: electricity. This is a complex issue, the kayak would have a 7W solar panel, which charges into a 2.2 Amph SLD (Sealed Lead Acid) battery. The battery is used primarily is for powering the boat’s bilge pump, and secondarily, to charge various electronics devices: the iPhone, Garmin, VHF radio GoPro, camera, the compass’ and signal lights, etc…

First image: the 6 – mm diameter plastic cable glands, with a cigarette lighter for size compare. These cable glands are used at various places on my Serene – 2 kayak, but primarily used for running tubes, cables through hull. With proper installation, they should be waterproof, with the extra help of some silicone glue. Second image: the rudder control lines’ tubes, running through 4 cable glands each all the way from the cockpit.

All electric cables on my boat would be placed inside plastic tubes, to maximize their waterproof capability. So they would also need some cable glands to run through the bulkheads. But that would be the next step of the project. Now, just all things rudder related! Third image: the rudder pedals, simple pieces of wood that could be rotated around hinges. Since all these parts are quite near the compass…

So the hinges, the screws… are all made of brass. I had a hard time finding these brass parts, cause most available on the local market is actually made of steel, just copper plated. It’s quite weird carrying a piece of magnet around the shops, to verify that they’re actually non – ferromagnetic, but I have to really make sure about that! For the compass, I would just used the same type as in my previous boat.

Though a simple and cheap compass, it has been verified (in my last 9 days trip) to work correctly and reliably. Before installing other parts, I slightly sanded the deck, applied some colored – thinned epoxy (for color staining, this time, the deck also has a yellow color like my previous boats, but much a lighter shade). Next would be glassing the external side of the deck, before fitting many other parts onto it.

There’re quite a lot of works required on the deck. First, I need to make various small wooden parts: the bungee cords’ anchor points (14 of them), the cleats (6) used to tie the hatches down, the rudder post, wooden balls for line pulling, etc… all is very “small” wood working, you would need to work on parts that a just a few centimeters in size, an ugly type of work which I don’t like, since I don’t really have skillful hands for that.

Second image: various wooden parts. First image: cut half – curve grooves for making the bungee lines’ anchor point using my router. The bungee would loop through that grooves, going from the external side, through the deck, then back to the external side again. There’re 14 anchor points like that to be installed, 8 around the cockpit, 4 on the aft deck, and 2 on the fore deck. Here, I learn to cut with the router following a template.

Third image: fitting the cockpit anchor points, the installation is quite simple and straightforward, the wooden blocks are glued on, with steel wire fastening through the holes, later some little putty would be filled in the jointing edges, and maybe some glassing too. This way, the bungee cords’ anchor points are made so simple, easier to implement, not the same nasty, clumsy way as in all of my previous boats.

Next in installing the rudder control lines’ tubes. Those are 6 – mm diameter (4 – mm internally) plastic tubes that run from the cockpit, through the day – compartment and aft compartment to near the stern, running through 4 cable glands on the way for each tube. The installation is quite messy, as I was using too much silicone glue, in an anxiety to assure that these cable glands would be completely waterproof.

Installing the cockpit coaming and hatches is quite straightforward: the fore and aft hatches, and the day hatch. Then I bevel the deck’s jointing seams (the external side) a bit, as well as the cockpit coaming, the seams need to be curved in order for glassing to go on well. Glassing the cockpit coaming could be a little bit tricky, as the fiber fabric should wrap around and cover both the internal and external sides.

Talking a little bit more about jointing the seams here. For the seams to be strong, I follow these 3 steps: first is priming the seams with some epoxy, then when the epoxy has not cured, apply the putty. Putty has lots of viscosity, so it won’t penetrate well into the plywood, that’s why we need epoxy as primer. And once the putty has only half – cured, I apply the glass tape. That way, the seams would be very strong.

First image: fitting the hatches. The hatches’ bases would, from beneath the deck, go through the cut – out holes, they serve as reinforcement rings around. Since the hatches’ bases and lids are of the same height, going through the deck would leave a small gap (about 4 mm) between them. That would be the place to pour some epoxy in, the type of elastic, softer epoxy which functions like the hatches’ gaskets.

I didn’t glass the internal side of the deck, just some fiberglass tapes at the seams. Instead, the deck would be glassed on the outside, which should offer better protection against water. The internal side only receives a very thin layer of epoxy coating. The external glassing would slightly overlap with the hull (about an inch), to better strengthen the deck & hull joint. It looks like basic jobs are done? Actually there’re still lots of works ahead!

Continue working on the new deck! The deck has 3 bulkheads of its own, corresponding to those of the hull. The two rudder control lines would run inside plastic tubes, which run through these bulkheads via waterproof cable glands. But that would be later, first is installing the cockpit coaming, which is just a thin plywood strip bending around a MDF frame. The coaming lip is also cut from plywood.

First image: you can see my beloved Fein Multi Master, the renown oscillating tool. Often when I have to cut or do other tasks in tight corners or in positions that are inaccessible or inconvenient to other reciprocal tools, this Fein is my last resort, and it’s always been very helpful to me. Here, I need to trim the already installed, but wrongly – sized bulkheads. Also, really love the tool’s Germany quality.

There’re some other tasks which are not reflected in the images here: fairing the hull and deck’s external seams, then glassing them with my fiber tapes. It’s not until now that I could comprehensively master the skills working with epoxy and glassing, using just the right amount of them. But also, I also gave up the idea of a kayak that’s as light as possible. For a training, exercising boat, lighter is of course better.

E.g: 15 vs 20 kg is a huge different, cause it’s much easier to launch and retrieve the (almost empty) boat for every training sessions. But for an expedition boats, a few kilograms doesn’t make much difference, since a loaded kayak weighs as much as 110 ~ 120 kg, with that mass, you can’t carry on your back anyhow, so a few more kilograms added would worth the value of a stiffer, more durable boat prepared for long journeys!

A major setback in the building progress, the curved deck didn’t come out with my expected quality. After released from the molding frame, the deck slowly bend back from its curved shape, especially amid of the boat, off from the desired geometry by 3, 4 cm (first image). That’s really bad… I made a hard decision to discard the rounded deck, and build a hard – chined one (like my previous kayak) instead!

I had an uneasy feeling, lots of work has to be redone, cutting and jointing the deck’s bilges (second image), setup the molding female frame. I took this chance to modify the deck design a bit, raising the aft part by 1 cm, to better accommodate the rudder control lines. A hard – chined deck doesn’t look as good as a rounded one, but it’s easier to build, easier to install other things, and it would fit with the hull much better.

Third image: forming the deck shape, the geometry is so simple that it doesn’t need any wire – fastening, just some CA glue here and there to fit the bilges together, some duct tape on the outside, then putty onto the inner seams. To save weight, I only glass the deck internal side at the cockpit area, where it could be potentially exposed to water. However, the deck would receive a glassing on the external side later on.

Fourth image: dry fitting the deck and hull… perfect fit! No adjusting, no fastening, no compressing would be required, just fit them together, then trim the edges! In the image, top of the cockpit area, we can see the cockpit coaming template (cut from MDF). That would be a frame for building the coaming lip and ring around, measured 38 x 64 cm in internal dimension. The external dimension would be 44 x 70 cm.

With my Dremel – Multi – 3000 tool, I made lots of parallel cuts onto the deck internal side (see the first image), the cuts are about 1.5 cm apart, and about 1 ~ 1.5 mm deep. Those are not very deep cut, since the plywood is only 4 mm (3.75 mm to be exact). Then I soak the deck with water thoroughly, for the ply to be softened, then put it into the frame and press it down… with my body weight (just sit on it).

With the extra help of some clamps, I press it down, little by little, don’t be too quick, just do it very slowly, then the plywood bends nicely into a perfect curved shape! There’s some minor cracks on the edges, but that’s not too important, cause those parts would be trimmed away when the deck would be glued with the hull. Second and third images: you could see how well done the curved deck is!

I let it there overnight, waiting for the water to vaporize, then apply some thinned epoxy onto the deck internal side, I also apply a few glass tapes at some places, that way the curved deck would hold its shape once released from the molding frame. Next would be puttying the rear part of the deck onto the forward part, a simple and straightforward job, then again, glassing the seams with my beloved fiberglass tapes.

Joining the fore and aft parts of the deck is quite simple, though it required some wire fastening to put everything under order. FreeShip (the boat design software) strangely generates a slightly abnormal curve around the cockpit (had I made some mistake, or didn’t use the software in a correct way?). So I had to manually draw the line by hand, guessing at some places, resulting in not a very good fit.