hello world – 1, part 3

aving worked with epoxy resin when setting up the workshop, I’ve gained some experiences with it. When mixing component A & B together, the pot time is so short in tropical climate, as the rule states that: reaction time is reduced by half when room temperature increased by 10° Celsius, I usually have less than 3, 4 minutes before it hardens. The average day temperature in Saigon this season is around 33° ~ 36°, it makes a tedious task working with epoxy, quite many times did the mixed epoxy burn hot into smoke before I can use it all. Epoxy also exhibits the characteristic of a “chain reaction”: it easily burns hot when the mixing weigh exceeds a “critical mass” of just 30 grams or so (depending on temperature), forcing me to mix into smaller batches.

7.     GLASSING

Finally, I devised a trick to cope with the situation: before mixing, I put the components A & B into the fridge for an hour 😀, to cool them down and lengthen reaction time, giving me more time and flexibility. Also, I would glass at night to avoid the higher day temperature. For the fiberglass fabric, I can only find cloth of 1m width at the current time, not enough to cover the whole canoe’s beam, but decided to proceed with it anyhow. The missing part will be left as is for the interior, and will be covered by other fiberglass pieces for the exterior. Though glassing would add about 2 ~ 2.5 kg to the final boat weight (just estimate, I use 6 oz, or 200 gram/m2 cloth), it would re – enforce the hull with more stiffness, anyhow this is my first build and rigidity is a bigger concern over weight.

8.     FITTING

The hull is now completed, the next step involves many small works that help building up the boat structurally: fit the forward and aft bulkheads (I decided to seal the water – tight compartments permanently and not to use hatches for later maintenance), fit the inner gunwales, fit the forward and aft thwarts, then fit the outer gunwales, then fit three bottom runners (to protect the boat when touching ground), and some other miscellaneous works. It seems there’s alway more effort and time spent in each step than I originally planned, partly because I’m an inexperience first – time boat – builder, partly cause I want to do it carefully to learn and improve my skills. It’s just like when you go on long – range paddling: don’t think about the destination, concentrate on each steps!

9.     MORE FITTING

For the gunwales, thwarts, seats… my chosen wood was a very hard and heavy tropical one, Vietnamese name: căm xe (Xylia xylocarpa) and the choice was not quite right. Having density at 1.15 (1150 kg/m3), the wood is too hard to bend into desired shapes, it’s even hard to saw or to chisel. I was thinking of setting up boiling devices to steam and bend the wood, but it requires much more effort, so finally I decided simply to compromise and change the design: instead of “flush decks” at bow and aft, I lower them a bit to fit with the “sunken” gunwales. Also, I’m worrying that this wood would add much more weight into the boat. On the plus side, hard wood makes the boat more sturdy, and if done right, its grain and colour would be very nice after polishing and varnishing.

hello world – 1, part 2

was having quite lots of work, those coding stuffs, and suddenly I recall a popular joke of the IT field: Question: how many software engineers does it take to change a light bulb? Answer: none, it’s a hardware problem! 😀. Plus the burden of many nameless tasks of the canoe building, sometimes I feel a bit tired. But occasionally on the way back to my workshop, I stop on the bridge, look out the wide scenes on the river. Boats of all kinds and sizes come and go, waves gently flapping the banks, the tide quietly rises and lowers, and the breezes murmur into my ears a long – forgotten melody: Moon river, wider than a mile, I’m crossing you in style, some day… And I felt that, the rivers are calling, they are calling me… To the next steps of the boat project…

4.     STITCH

This gonna be a fun part cause it resembles a kid’s game when he/she just cuts pieces of paper and stitches them together with glue. Forming the boat hull from plywood planks is much the same way, on a larger scale, hence the boat construction method named: stitch and glue. Starting from the center bilge, I drill 2.5 mm holes at 22 ~ 24 cm intervals to stitch the next 2 pairs of bilges together using short pieces of steel wire. Then I fit the forward and aft bulkheads, also the center mold, then stitch the final upper bilges. Let take a look at this photo album to see in details, how, in just a couple of hours, the hull gradually takes shape. It’s really fascinating to have completed this step, it produces the first impression on how my canoe would eventually look like! 😀

5.     GLUE

The bilges are just temporarily hold in place by steel wires, next is to permanently glue the seams with thickened epoxy. I used a mixture of silica and wood flour (the collected sanding dust) to thicken epoxy, then apply to the seams with a small masonry trowel. The two sides of a seam are covered with duct tape in advance so that epoxy won’t mess around, and duct tape is removed when epoxy half cures, leaving a clean fillet line. The next steps are glueing the bow and stern sections, cutting steel wires, filling remaining empty slots, then turning the hull over and do the same thing on the exterior side. There’s actually not much work, but it require leaving epoxy overnight for it to completely cure before glueing more, it gonna take the next few days to finish this step.

6.     SANDING

Now the labour – intensive task of sanding (even with the help of power tools). But first, I would need to fair the seams’ fillet curves a bit with the angle grinder using 60 grit sand paper. Then fill all drilled holes left by the steel wires, then proceed with the random orbital sander through 3 levels of fineness: 80, 100 and 120 grit. Since the glueing was a bit messy, it puts more work into this step, to really smoothen the hull’s surfaces before being able to move to the next step. Sand the hull, wipe out all dust, sand again with finer sand paper, repeat 3 times and for both outside and inside, that means: lots of work, given that next week would be a busy week for me with my job! 😢 But those “gorgeous curves” gave me lots of joy and encouragement on the to – be – finished – product! 😀

hello world – 1, part 1

y first boat project now officially starts! 😀 I’ve been thinking about building my own boat for a very long time, but still couldn’t arrange for it. Now, just have to stop daydreaming about “the ultimately – beautiful watercraft of my life” and roll up my sleeves. Given my poor woodworking skill set, after lots of consideration, I’d decided to start with a simple design and construction method, a 12 feet (3.66 m) Selway Fisher’s Asymmetric Baby Raven, intended to be my general purpose / fishing canoe with the given name: Hello World – 1 😀. In the upcoming blog entries, I will try to keep a log on the building progress, which is expected to finish within a month or so, cause I would mostly work at weekends, and some limited hours in the weekdays.

1.     PREPARATION

It took almost 3 weeks to make all necessary preparations: building myself a table and a shelf to store tools and materials, a simple workbench to work with the boat on. Also, I built a bed, a smaller shelf and a chair, all of the simplest kinds, as household objects. That is to get myself familiarised with woodworking, gain some experiences with wood, epoxy, fiberglass fabric… There were lots of new stuffs for me, whose hands have rarely touched those kinds of job before. Anyhow, my small workshop setup is now basically completed: hand saw and power jig saw, a drill kit, random orbital sander, a disc cutter, hand plane, chisels, clamps, pincer, hammer… paint, brushes and rollers… I even have a small electronic scale to help epoxy resin mixing more accurate.

2.     CUT

It’s easy to find exterior – grade plywood to WBR (Water and Boil Proof) standard, but it’s hard to find really – good exterior – grade, not to mention marine – grade ones. First, many of the so called “water resistant plywood” out there in Vietnam market use melamine, not the superior phenolic glue. Second, most of them are laminated from cheap poplar veneers, the best I can find so far are those with interleaved layers of poplar & tropical hardwood veneers, usually marketed as: meranti or okoume, but I guess they’re just other tropical hardwood equivalences. Today, the ordered plywood sheets have arrived (I use 5mm thick ones), it’s time to draw and cut the planks. As usually said: measure twice, cut once, I proceed slowly & carefully to this initial stage of the canoe.

3.     JOIN

I was too busy during this week to actually got any boating bit done, need to get all the cutting and joining jobs finished this weekend… Finally, the complete set of planks is cut out. Before joining, all bilges need to be trimmed down to the precise shapes. I clamped each pair of port and starboard bilges together, then used an angle grinder to trim the edges and smoothen the curves. Since the plywood sheet has length of 2,440 mm, they need to be joined to the 3,660 mm length of the canoe. Bilges are screwed down to a piece of wood to fix the position, a layer of bin bag is placed in between to prevent the wood from sticking together. Then I applied epoxy, pieces of fiberglass, and epoxy again until the glass is completely wet out to form simple butt joints which get the jobs done.