hello world – 3, part 8b

Trường châu cô nguyệt hướng thuỳ minh…

ade some more miscellaneous improves to my HW – 3 kayak… First is filling the two boat’s ends with Polyurethane foam. For an example of how PU foam works, see a demo video here. It takes just a few minutes for the mixed – two components to expand into a closed – cell (water proof), somewhat rigid structure. The foam I bought is exactly the one used for refrigerators’ insulation (see the 2nd image below, two bottles containing two components called: Polyol and MDI).

The foam adds about 600 ~ 700 grams to the boat’s weight, it fills about 1 meter of boat length at both two ends, occupying a total volume of about 60 liters (estimated). This is just an act of precaution, as in the worse case should the boat cracks, or if there’re holes punched into the hull, the whole boat could be flooded, but it will still stay afloat. I erect the kayak upright, pouring the mixed PU foam through the hatch, wait for 15 minutes, then repeat the same thing for the other end.

Instead of making a complex foam seat as I originally planned (which could be very time consuming cause it requires creating a mould), I chose to install instead the simplest thing that works. Bought a small plastic kid seat, cut the four legs away. A strap line helps holding the seat in place (bolted to the cockpit coaming) and supports its back. The size of the kid seat is about right, not too small for a comfortable ride, and not too big so that a spray skirt could be deployed later.

This season, Christmas, Gregorian New Year until Lunar New Year (about 1.5 month from now) the city is decorated with all kinds of lighting, creating splendid sceneries. I’ll try to have some night paddling to capture those colorful moments. With the overpopulation situation in Sài gòn becoming worse and worse day after day, I dare not step into the urban districts these days anymore, viewing the city from above the water seems to be a very nice alternative option to me 🙂 !

hello world – 3, part 8a

Kính hồ lưu thuỷ dạng thanh ba…

aving made some more thorough testing, I’m now feeling very pleased with the new boat and its build quality. After several 20 ~ 25 km paddling trips, I think I can average out at 7 kmph for extended time (5, 6 hours) and probably longer with more endurance exercising. That’s still not up to my expectation yet, but about speed, on the internet, you can hardly find trustable reporting on kayak and its paddler’s abilities, some boating information is purely… bloating!

At some points, due to the lack of correct information, I did have some illusions on paddling speed. But now I definitely know that a typical good sea kayak has the average, sustainable speed in the 7 ~ 7.5 kmph range. Beyond that would be the domain of racing kayak or surfski, which could step into the 8 ~ 9 kmph range, the best of which could not reach too far beyond 9 kmph. And that probably would be the target of my next build, though currently I have no plan for it yet.

Unlike HW – 2, I feel very comfortable to paddle HW – 3 into the wind. The hull pierces waves nicely, and I think the boat would surf well also. Haven’t had the chance to trial the kayak in big standing waves, but in some lesser situations, I’d noticed that the boat rides waves in style, with very little drifting, shaking. That’s a characteristic very much needed when I would leave the relatively – calm rivers to go into the much more choppy areas of coastal sea and large estuaries.

It’s approaching year end and I’ve got lots of other stuffs to do, so there won’t be any big updates to the kayak until next year. It’s a real pleasure when on rivers, people was asking where I bought the boat from, and when I told them that I built it myself, none believes it 🙂 ! This season, day temperature is dropping below 25°C (that’s already called “cool” for a tropical Saigon), good for going paddling indeed. Some video shots to show the boat, captured with my GoPro mounted at bow.

hello world – 3, part 7c, mise à l’eau

Khứ lai giang khẩu thủ không thuyền…

roudly present the new – kid – on – the – block, the flagship to join my armada 😀 ! The first image below: the boat and her quite – satisfied builder / owner 🙂 ! Today is launch day (the French phase mise à l’eau simply means: put to water), I tested the kayak for a short trip of about 15 km. The first thing to notice when sit in and start some paddling strokes is that the boat has extremely good primary and secondary stabilities, unlike my previous HW – 2.

All boating measures is relative, and you trial to find out what works for you. HW – 3 has very good stabilities, or at least I’ve get used to those not – as – good of HW – 2. The boat tracks very well, I could have the skeg completed retracted on somewhat calm water. The turning radius is still large, not something abnormal for kayak of this length, the boat behaves nicely and responses well to my edged turning actions. I have nothing to complain about its tracking and turning capabilities.

Speed sees a good improve, I can easily average out at 7.5 kmph (flat water, measured in 2 hours), about 1/4 better compared to that of HW – 2, well for sure HW – 2 is only a 14 footer. Actually, I was expecting a greater improve in speed (about 1/3, not 1/4). Anyhow, I need to get familiarized with the new boat, and to figure out the exact measuring numbers. Also I noticed that the boat is a bit heavier at stern, the lowest point of the bow sometimes pops out above the waterline.

That suggests me to shift the weight balance toward the bow a bit (e.g: arranging the carrying load), to gain the waterline length a little longer, to improve speed further. Well, the next couples of weeks is just paddling and paddling, to improve my endurance (I’ve been having little practices for the last two months). I would need to make some longer trips (about 20 ~ 25 km each) to get known to her, the new boat, and to see how she would behave in rougher water and weather conditions.

hello world – 3, part 7b

Nhật kiến cô phong thủy thượng phù…

hen all the vinyl decals are in place, I started varnishing the deck. A note about vinyl stickers, which I can have them cut at a local shop for a cheap price. The last time, I designed all with Photoshop, then export to EPS format. Unfortunately, Corel Draw does not understand that EPS very well. Corel is usually the software used to operate the vinyl cutter machine: the vector editing program just “print” the designs to the vinyl cutter, which handles all “drawing” (cutting).

This time, I thought of a new way, I used Photoshop to design all the graphics, and export them to large black & white images (PNG). Then in Corel, I used the “Trace Bitmap” feature to try converting those bitmap data into vectors, which usually works very well for B & W (2 colors) images, then have them cut by the vinyl cutter. At least for some simple graphics such as logos, short texts… this way works well enough, and I don’t have to spend time learning more about using Corel Draw.

The deck varnishing went on smoothly, with the lessons learnt from varnishing the hull. The 4th, 5th images below: installing the skeg, the bungee cord pulling the skeg toward the stern, and the paracord holding the skeg in place toward the cockpit. Note that I attached the bungee and the paracord directly to each other, so that the thin skeg blade won’t withstand the tension of those pulling lines, it just follows the control. Note also the 5 knots used as 5 levels of skeg lowering & raising.

Install the fore deck lashing bungee lines, attach the two grab handles and it’s done! Some may have noticed that the cockpit doesn’t have the cheek plates and the seat, but I’ll keep it simple for now. I’m used to sitting just on bare wood, with no back rest, even on prolonged trip, that’s fine for me. Well, the boat is now ready for some “technical trials” 🙂 , to see how it behaves on water. There’s still a long way equipping it for real voyages, but that would be later. Now, to the water! 🙂

hello world – 3, part 7a

Đạm đạm trường giang thuỷ
Du du viễn khách tình…

oday, I sanded the hull slightly, to partly remove the previous unsuccessful varnishing. Then I painted the contour line where the deck and hull meet before proceed on re – varnishing the bottom again. Images below: using duct tape to mask the line, the result is quite eye – pleasing, the line helps better hiding the imperfect deck & hull joining, it create an “optical illusion” that the joining is smooth. Next is to varnish the whole boat external sides, hull and deck.

By “varnish”, I mean layers of transparent two – parts PU paint over the surfaces. (In Vietnamese, the word “varnish” still refers to the old – day, alcohol – based finishing agent which used to be popular, but largely forgotten nowadays). The varnishing need to be done quickly, as it’s less than a few minutes before the PU set, brush one small area at a time, proceed on, don’t look back to correct previous mistakes. I find a normal painting brush more suitable than a foam roller for this kind of job.

At this point, I made a hard decision to abandon all planned decorations. Initially I’d intended to do some inlays: veneer and mother – of – pearl. But doing so will take a considerable amount of time, which I don’t really have in the coming months, it’s approaching year end and there’re lots of other things to be done. Wood inlays requires skills and patience. I’d thought I could do it with some practices, and I’m not going to rush the boat to water. But now, just some simple vinyl decals instead.

It’s something about balance… an elaborately decorated boat is beautiful to look, but maybe I just need a good, nice boat to play on water. Admittedly, there’s an urge going to water in me, after almost 2 months working on this HW – 3. So, I just put a compass rose pattern on the forward deck, plus the boat name and some owner’s information on aft deck, and of course the boat’s eyes at bow, that would finish my minimum decoration plan to proceed on to the next step.

hello world – 3, part 6c

Hợp tảo Ngũ Hồ song Phạm Lãi…

anding, sanding and sanding… lots of sanding required to finish working on the deck, the cockpit, the hatches and other parts. Also, the bottom paint is not up to the quality: the puce color is too dark, and the gloss is not good enough (the 2K paint I use dries out too fast, many of the times, the roller becomes very sticky and hence doesn’t make a smooth surface). Thus I would need also to sand the bottom down again and apply another layer of clear top coat.

But first, I would need to slightly sand the cockpit coaming and paint the whole cockpit in puce color. Like before, I just use transparent PU paint manually mixed with some color pigments. In the same way, I would paint the whole deck, but use another yellowish wooden color pigment instead. Well, after all, I want to show off some wooden colors, if it’s just some pure black, white, blue, green… it must have been much easier. The results… once again, are not totally satisfying! 🙁

The deck looks dark and a bit… dirty. Painting has always been my weakest point in the whole boat building process, partly because I can’t find really good painting products here in Saigon, partly because my skills on the painting part are not good indeed. Yet worst, painting and varnishing are the steps that decide how your boat would finally look, they define the beauty of the watercraft, few would notice details in boat structure or construction. I’m feeling a bit upset!

Well, the boat appearance now is not as nice as I was expecting, to be honest, and it’s too late to correct the made mistakes. This would have another side effect: all decorations would be reduced to the minimum, partly because I would have little free time the coming months, and also, to simplify some up – coming tasks. Saying to myself: this gonna be not a furniture going to water anymore, but a nice – to – paddle, sturdy – built and trust – worthy boat instead!

hello world – 3, part 6b

Mãn thuyền không tải nguyệt minh quy.

oining the hull and deck, now comes the time the boat “transforms” into its final shape! 🙂 I used lots of fastening lines to press fitting the two halves, after sticking some putty along the inwales. The B5 epoxy mentioned earlier is very slow in curing, so I had plenty of time to work on the joining. The bow fits perfectly, I could just use some duct tapes to hold the deck down. Toward the stern is not as good, and I had to use the compress – air gun to help nailing together the two parts.

The mast base sticks well to the cross – shape structure underneath, now wait for several hours for the putty to harden. The bevelled inwales make small “gutters” with the deck, I utilize this fact to slant the boat a bit, then use a small medical syringe to pump epoxy along, the epoxy flows and fills the remaining gap, securing a tight fit. Then I erect the boat upright and pour epoxy into the two ends. Next would be glueing the bulkheads to deck, that would finalize the hull & deck linkage.

Look at the last image below, the boat has not taken on its final appearance yet, but the shape looks so gorgeous, doesn’t it!? 🙂 A long, slender shape that promises greater velocity and reduced paddling effort. Also, I finished the skeg box installation by glueing it to the deck. In the 6th image, you can see the through hull, through deck well housing the skeg blade, which will be controlled by a bungee cord tied to the stern, and a paracord line toward the cockpit.

Weight once again exceed my initial estimation, it’s a bit heavy now, but if it stays under 30 kg, that would be fine for me. I would go with a sturdy boat on long journeys, rather than a light, but fragile one. The boat is almost operational at this stage, just install the skeg and it’s ready to go! Well, to be precise, it’s just ready for some “technical trials”, there’s still a lot of things to do: finishing, fitting, accessories, other equipments, etc… Consider to be half way through my Hello World – 3 planning.

hello world – 3, part 6a

Di chu bạc yên chử,
Nhật mộ khách sầu tân.

inishing works on the mast base. Although sail is something not included in this “version” (intended to be installed sometime next year), the mast base need to be ready for now, before the deck and hull are joined together, or else it would be very difficult to work on later. It takes me lots of time shopping around to find the appropriate hardwares to be used as the mast base, and I found some good ones, all made of stainless steel (shown in the 3rd image below).

There’s absolutely no kayak accessories store of any kind in Vietnam whatsoever, so by “kayak hardwares”, I mean I was seeking for something that can be equivalently used on a kayak. Also, it’s very hard to find the parts, cause there’s no common “terminologies” used to name them. When I want to find something, I usually go to the vendors with a picture of the thing I want to have, and they would come out with something similar, that’s how the communications go on!

For the mast base, I glued a small wooden plate under the deck, right at the base position. The base is then bolted down through deck onto this plate, which in turn, glued to a supporting cross – shape structure linking deck with hull. That would be strong enough to withstand the mast and its sail. The mast would be stepped, and rotatable on the base, with four stays to hold it upright. Well, sail when you can, paddle when you must sounds to be very pleasing on my future journeys. 🙂

I covered the hull and deck’s internal sides with a thin layer of white paint. With bright white color, it’s easier to find things in the storage compartments. Then I slightly sanded and painted the bottom with two layer of transparent paint mixed with the puce pigment. A few more miscellaneous jobs needed before the two halves could be joined together. The 5th image below: test fitting the hull and deck, check fitness and some small adjustments here and there.

hello world – 3, part 5c

Tiếng sóng xô bãi cát,
Tiếng biển xanh đang hát…

Tiếng sóng – Dương Thụ

ontinue to work on the hatches… In my thinking, using the hasp locks is a nice way to hold down the hatches: secured and easy lock / unlock, tight fit, no hassle of lines or bungee cords. But still I have a little concern that those small metal parts could affect the operation of the magnetic compass, which would be mounted nearby. But most good modern compass nowadays should probably resist well to those small ferromagnetic interferences.

Initially, I intended to install three locks per hatch, but after some considerations, I installed four. With three locks, only one failure could easily let the hatch open, while with four, it would take at least two failed locks to make the hatch unsecured. It takes me a few hours to check fitting the hatches’ grooves, then using 3mm – diameter bolts to nail down all the parts (all is made of stainless steel). The result is quite pleasing: all hatches is tightly fitted and well secured.

Next, I make some slots to install the rigging. These are intended for some “heavy – duty” lashing used for the sail. The idea is simple, but it took me some times to figure out how it works: drilling two small holes near each other, then pull a short piece of plastic tube through those holes, then fill the inside with epoxy putty (the tube is waxed to prevent it sticking to the putty). When the epoxy cures, pull the tube out, that would leave behind a “tunnel” to push your lashing line through.

I make only four “anchor points” like this, as it require some “strong holdings” to rig the mast and sail. The other deck riggings, I would just use some screws, bolts and bungee cords. I would try to keep the deck rigging to minimum, no perimeter lines, as I don’t feel very comfortable with a cluttered deck with too much lines and cords and other hardwares, the sail plan would add a bunch of them in addition later on. Also, I don’t really want to punch too many holes through the hull anyhow.

hello world – 3, part 5b

Đàn anh đã cho tôi trời xanh bao ước mơ tuổi thơ,
Đàn anh đã cho tôi dòng sông mang cánh buồm khát vọng…

Mặt trời bé con – Trần Tiến

roceed on making the aft and forward hatches. I’ve changed my mind to make those hatches as simple as possible: all will be flush – deck, rounded hatches hold down by some hasp locks. (The plan proposes making a twist – lock one for the aft hatch, but that would take considerable effort to get done right). Also, I’ve decided to move the forward hatch further aft, to get the deck space to install some sailing hardwares (compass, blocks, cleats…) later on.

I’ve cut some plywood rings: one spacer ring, one lip ring, and two groove rings (to prevent water leaking in) for each hatch. The forward hatch is quite small indeed, 22 cm in diameter, and 34 cm for the aft hatch. Actually, I prefer shapes that can be geometrically defined, so abandon the egg – shape forward hatch as proposed by the plan. Next would be the simple task of glueing them together. Also, I’ve cut a slot on the aft deck section to get the skeg box through.

After glueing the hatch lips to the hull, I put small fillet lines at the seams before glassing the internal side of the lips. Then I apply several layers of penetrating epoxy (epoxy thinned with xylene) onto the hatches’ rings, grooves… before applying another layer of un – thinned epoxy, then would come the painting in a later phase. All these parts could easily wear out after some times of use, so they need some special cares. Then come the hasp locks, four locks per hatch.

I was thinking over about the use of hasp locks. Usually, on sea kayaks, they avoid metal part, cause it could get corroded by salt water. But good metal part plus proper maintenance can prolong the service life to years, before it can be replaced. The only problem with these locks is that putting them on deck could cause you some small injuries in self – rescue actions, e.g: if you’re thrown out of the boat in heavy sea, the locks could scratch your skin when trying to get in again.