serene – 2, part 22

ontinue 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!

serene – 2, part 21

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.

serene – 2, part 20

ith 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.

serene – 2, part 19

irst image: the basically completed hull, put aside, now working on the deck part. Compared to the hull, which is… simpler and more well defined in term of geometrical shape, the deck is just loosely draft out in overall shape, it’s cut slightly over size, so that when fitted together with the hull, it would be trimmed to match. The construction is also more complex, due to the rounded shape of the forward part.

I had a hard time thinking about the cockpit and spray skirt size. A width of 44 cm is almost the minimum that could fit a cockpit, that in turn, could fit the smallest spray skirt sold on the market. Ready – made spray skirt (e.g: Snapdragon, Seals, Sea to Summit…) usually have 44 x 75 cm as the smallest dimension, other than that, you would need to order a custom made one, which is an expensive and complicated process.

Second image: drafting out the deck shapes on plywood. Third image: jointing the pieces together, again with those simple finger joints. Fourth image: the two main “components” composing the deck, the aft (far, left), and the front (lower right). I slightly bevelled their edges at places, so that they could fit more precisely together. The white duct tape: pin down the parts so that they’re correctly symmetrical along the longitudinal axis.

Next is the very important job of torturing the deck into rounded shape. By now, I’ve realized that there’s too much curvature on the molding frame, and I wonder if the plywood could bend that much to make a very curved shape, only experiment would tell. In order to help the ply bending well, I would make many longitudinal cuts on its internal side, then wet it completely overnight for the wood to become more flexible.

serene – 2, part 18

fter the internal side get glassed, goes in the gunwales (American English: the sheer clamp), port and starboard at the same time. The gunwales are very thin strips of wood, 2.5 x 1 cm in cross section, and are bevelled at 45 degree all along its length (they are bevelled with my table saw), later the bevel angle would be adjusted along the boat hull (with an angle grinder) to better accommodate the deck.

Second image: the 3 bulkheads, the small compartment right behind the cockpit would be the place of the day hatch, to store food, drink and other various things you would frequently need during a paddling day, and could be accessed while afloat (still sitting inside the cockpit). For other hatches, you would need to beach the boat in order to access them. Third image: the bulkheads are filled with putty at the joints and glass on one side.

Fourth image: triangle blocks of wood use to reenforce the joint between the gunwales and the bulkheads. With no need for nail or bolt, the triangle wooden blocks link the squared corners, this way, the kayak’s “frame” would be significantly stronger, stiffer, a simplest, yet elegant solution 😀. There’re two additional thwarts installed near the bow and stern to strengthen the boat’s overall structural stiffness.

Completed most jobs with the hull (there’re some more on the external side of it – puttying, glassing… but that would be a later phase of the project), now moving on to the deck part. It doesn’t seem immediately apparent, but the deck part is a more complex part, compared to the hull, it would house many things: the 3 hatches, the compass, the rudder pedals and control lines, the anchor points for bungee cords, etc…

serene – 2, part 17

inishing the fist step of forming the hull into shape, then filling the seams with putty and glass them with my 2 – inches fiberglass tape. The glass tape is my life saver, thanks to it helps again, that the seams could look neat and nice. To this day, I’ve acquired enough experiences and skills working with epoxy and putty already, so I’ve been able to mix the very precise (usually very small, e.g: 30 ~ 60 gr) amount required for each task.

Remember my very first days coming to boat building, working with epoxy has been a nightmare, that extremely sticky substance that messes and flows around. I have a very good feeling that everything is completely under my control in this build: the bilges fit tightly, the bulkheads fits very well, there’s no need to adjust here and there, the amount of epoxy and putty used could be estimated with quite an accuracy.

Second image: dry fitting the bulkheads, this time the cockpit would be slightly larger, to accommodate the bilge pump, and the rudder control pedals. Third image: fitting 2 prism – shape wood blocks at the two ends of the kayak, one at the bow for getting the pulling line through, and one at the stern to mount the rudder post. Again, very little epoxy and putty used, the wooden blocks add some saving to the final boat weight.

Fourth image: glassing the internal side of the hull, I’ve been thinking over and over again about this issue, do I really need to glass the hull internal side, consider the glassing seams are quite strong already. Finally, I decided to glass anyway, as my plywood is not of very good quality, it’s better to have some protection in the long run, with the cost of about 0.4 kg of epoxy (plus the fiberglass fabric) added.

serene – 2, part 16

itting the bilges is quite straight forward. Compared to my previous boats, this time, due to more careful drawing and cutting, having a good shape, the bilges fit together pretty much better, there’s almost no gaps between them. It requires still some little fastening with wires, but not much, and some dots of CA glue (cyanoacrylate) to help the edges staying head – on. Then I proceed to filling the seams with thickened epoxy.

First image: the bottom pair of bilges fit together. Seeing them fitting so well to the molding frame, I decided to putty – fill and glass the bottom seam before adding the second pair of bilges (second image). I really appreciate my 2 – inches – width fiberglass tapes, they help the seams to be very clean and tidy (and hence less epoxy used). With out them, fiberglass cloth bias cutting would be a nightmare for me…

…As the kind of fiberglass cloth I’m using is not too good in quality. Third and fourth images: the second pair of bilges goes in, also very good fit, requiring little fastening. Due to the sloping sides of these bilges, filling the seams with putty could be tricky, as the thickened epoxy wouldn’t hold shape but flowing down slowly due to its viscosity. So, I apply a small amount of putty, then immediately cover them with duct tape.

This way, the epoxy would hold shape, leaving a good looking seam. After the epoxy completely cures (about 8 hours in my case), I peel off the tape. It’s so good a feeling to see your boat take its initial shape. I spend sometimes standing, watching the bow and stern, its full water line, its slim and sleek lines. Still many things to be done, but this gonna be my Andalusia horse on the wide wild wet water space! 😀😀

serene – 2, part 15

roceed to cutting and jointing the bilges. This step is done quite quickly as I’ve now had plenty of experiences 😀. I read the offset – table directly from the FreeShip software, then draw the bilges on the 122 x 244 – cm plywood sheet. For the 17 feet hull, there’re 3 pieces per bilges, and hence, 2 joints need to be made for each bilges. I clamp 2 plywood sheets together and cut the port & starboard parts at the same time.

It takes some little skills and experiences to make the joints perfectly fit with just a jig saw. And I still prefer the straight finger joints as used on my previous boat, they are simpler to cut, simpler to align and to make sure that the jointed bilges are in correct shapes. Too bad, my plywood is of too poor in quality, it’s so fragile, so easy to crack, so I have to take extra cares at this steps, or the “fingers” of the joints could break.

First image: transferring the lines from offset table to plywood boards (with the help of a cup of coffee 😀, be careful not to make any mistake). Second image: all pieces cut, third image: the finger joints (no glueing yet). Fourth image: jointing the pieces together with epoxy (just use many weights to press on), then glassing them (the internal sides) with one layer of 6 – oz fiberglass.

Decided not to bevel the bilges’ edges, though beveling helps making tighter seams, my plywood is quite thin, so the seams wouldn’t be very perfect, they hardly could stay precisely edge on edge with each other (and beveling adds some more works to be done). With Serene – 2, I proceed with the hull first, then the deck, not doing them in parallel like my previous boat, as the deck part could be quite complex this time.

serene – 2, part 14

raming for the deck is more complex than the hull, since the deck would be curved in cross section, it require torturing plywood to a considerable degree to acquire that shape. From my previous experiences with bending plywood panels, I decided to break the deck framing into 2 parts, one is female, the other is male in shapes, then compressing the plywood sheet in between using many G – clamps.

First and second images: cutting the deck framing stations, can see clearly that the upper and lower parts of the deck frame are cut from the shame plywood sheets. Unlike the hull’s stations, which is positioned at an interval of 60 cm apart, the deck’s stations are placed denser, one for every 30 cm. The deck plywood would be tortured between these upper and lower stations to achieve the desired curved shape.

Bending plywood, particularly the 4 – mm thich ply I’m using, could be a hard task (and currently I don’t have any 3 – mm or thinner ply readily for making the deck). More over, the plywood I purchased is not of very good quality, it could crack too easily. So I would need lots of tricks to get the job done: soaking wet the plywood overnight with water to soften it, using hot boiling water to soften it even more.

(Currently I don’t have any wood steaming device, and there’s no plan to build one just yet.) Another trick for bending plywood is making shallow cuts longitudinally onto one side of the plywood sheet for it to bend easier. Fourth image: the curved stations of the deck glued on. Now all jobs related to the framing is done, next would be proceeding to cutting and joining the bilges… the long and hard way is still ahead 😀!

serene – 2, part 13

imple thing that is done many times already, since the very first time I was building the Hello World -3 kayak, so there is nothing special about setting up the “female” frame for shaping up the kayak hull and deck. The stations (as called so by the software FreeShip) are placed evenly at an interval of 60 cm, there are 8 of them for the 17 feet (approximately 518 cm) hull. All is cut from 18 mm – thick MDF.

First image: the stations cut, second and third images: since the 18 mm – thick MDF I used is at the maximum that my compress – air staple gun could handle, I simple glue the stations on along a MDF board, each 60 cm apart. You can see the stations numbered, from H1 to H8 (from stern to bow). Fourth image: another view of the completed female frame, looking this way, one could see that the kayak hull is so slim. It’s so indeed! 😀

At 44 cm, this Serene – 2 kayak is just slightly narrower compared to my previous boat. Serene – 1, which was at 45 cm. One of the main reasons why it took me so long to start this kayak building is that, I greatly appreciate my previous boat’s abilities in rough water, it did give me a lots of confidence. I wouldn’t want to lose that very special capabilities along my design progress, while improving some shortcomings…

…That my previous kayak had had. It is a very good feeling watching the “female – molding” frame, which gives me a very first impression on how my future boat would look like. But the long way is still ahead, it would take much efforts in completing my “perfect sea kayak”! By the way, the “rule” for choosing a sea kayak hull is that: build / buy a longest and thinnest one that you could still find it controllable and comfortable! 😀