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Today is a moment of truth: time to
test out my sheer clamps as an alternative method of attaching the deck.
Uh-oh! I'm immediately seeing some -- well, let's call them "opportunities
for creative problem-solving." First of all, it looks like the deck assembly is overhanging the sheer planks. Perhaps
installing the sheer clamps had the effect of pulling the sides of the hull in a bit. That would not be a disaster; I could
just trim to fit. But wait, there's more: see how one side of the deck assembly tends more toward the horizontal, while the
corresponding plank on the other side tends more toward the vertical? That's a problem that I'll have to deal with. Just to
be sure I'm on the right track, I contacted John Harris, the owner and chief designer at Chesapeake Light Craft, fully prepared
to have to buy new parts to replace the ones a seem to have screwed up! But John helpfully suggested that I carefully razor
through the fiberglass tape along the underside of the offending deck joints, move everything around to the proper position,
re-clamp and re-glue. That's the way they are at CLC: they don't just sell you a kit and walk away; they really are there
to help. Thanks, John.
Yesterday, I clamped on the second layer of the sheer clamp laminate
just to see how it would fit. Today, I'm going to glue it in place.
Before gluing the laminate in place, however, I marked the spots
on the hull with tape and pencil to show where the sheer bevel patterns would go. It's a lot easier to know this in advance
than to try to juggle a tape measure while you're trying to hold bevel pattern, a spring clamp and an epoxy-slathered wood
strip all at the same time. I put the strip into place with a spring clamp, then used the pattern to determine how much higher
or lower I needed to position the wood strip to create the correct sheer bevel.
After all the second-layer strips were glued and clamped into place,
I went around with all the sheer bevel patterns to double check and make sure nothing slipped out of place, since clamping
wet epoxy-coated parts can be unpredictably slippery at times. Then, before I quit the garage for the day, I eyeballed the
inside of the hull to make sure there was no glue squeeze-out running down.
Feb. 28, 2012 Day 21 Yesterday, I finished
up with the first 3/16-inch layer of a laminated sheer clamp glued into place. Today, I'll start work on the second layer
in the laminate, bearing in mind that it will have to be placed in a way that will allow me to achieve the rolling bevel that
I mentioned yesterday. So the first thing I have to do is figure out what the bevel angle is at any given point on the designed
hull. Fortunately, I happen to have a completed Wood Duckling right to hand, and I plan to measure the bevels that are present
on that boat, then transfer them to the one I am working on.
This is the tool I use to measure the bevels on the existing
boat. It is called a "sliding T-bevel gauge." To use it, you loosen the knurled knob, match the angle to the bevel
you want to measure, tighten it up again, then trace the angle onto a piece of cardboard or thin plywood that you can use
as a pattern to transfer the angle. This one is available at Lowe's for about $11. They also have a less fancy one for about
$5.
Sliding T-Bevel Gauge at Lowe's
I don't really expect you to have an extra Wood Duckling lying
about, so in case you are interested in following my "sheer clamp" method instead of CLC's recommendation, the next
set of pictures shows the seven relevant angles and the distance from the bow where they occur. You can print the pictures
out, if you want, then use them to cut your own patterns.
The angle at 6 and 84 inches aft of the bow....
The bevel at 12 inches aft of the bow....
The angle between 24 and 52 inches aft of the bow....
The angle at 60 inches aft of the bow....
The bevel at 72 inches aft of the bow....
The bevel running from 96 inches aft of the bow to the stern.
Hey, wait a minute! This boat is only 8 feet long; so what's with the measurement going from 96 inches (which is 8 feet)
to the stern? The answer is that we are measuring along the curved edge of the sheer, which is about 4 inches longer than
the straight 8-foot line down the center of the boat.
Next, we cut these scraps of plywood with the angles transfered
onto them into patterns that we use to figure out the bevel angle on the sheer of the boat we are building.
Then, we use the patterns to gauge how much higher or lower the second
layer of the sheer clamp is, relative to the first layer, at any given point along the sheer line. Ultimately, when both layers
are glued into place, we'll use a small block plane and/or a chisel to fine-tune the top surface of the combined sheer clamp.
In total, the sheer clamp will be 3/8 inch thick, which should be enough to hold the screws that will temporarily keep the
deck assembly in place while the glue dries.
Feb. 27, 2012 Day
20
This is the day I begin a major departure from the CLC instruction
manual. CLC wants us to wire the deck assembly to the hull assembly, then reach inside with a tool made from a stick with
the head of a disposable bristle brush screwed to it, rolling out a pre-saturated length of fiberglass tape, to position it
precisely (more or less) along the seam joining the deck and the hull. "It's easier than it looks," CLC assures
us. I've done it twice, once on a 12-footer and once on the first 8-foot Wood Duckling I made for Julio. Others may be better
at it than I, but for me this is not easier than it looks. It is the least enjoyable part of building this boat. As far
as I am concerned, there has to be a better way! I've decided to go with a traditional "sheer clamp." That's a long
piece of wood that's fastened to the length of the hull, then the deck is fastened down to that, joining the deck and the
hull. In theory, this should be simple. In practice, not so simple in this design, because the angle between the hull and
the deck is a "rolling bevel," meaning it is not constant, but changes all along the length of the boat. So the
top surface of the sheer clamp has to change its bevel to accommodate the deck assembly at its various points. I still think this will be a less stressful approach than the one that is prescribed.
I've never done it before on this type of boat, so I am operating on faith in my own design sense and workmanship. Some
may call this "chutzpah," which happens not to be a nautical term (but should be, considering that it describes
the mental state that so often precedes a trip to the bottom of the sea). So follow me along and see if I emerge a hero or
a goat!
The first step is to start building up the sheer clamp. I've
decided to do it with a lamination of two layers, each consisting of a 3/16-inch thick batten cut from the edge of a knot-free
3/4-inch plank. (In this case, believe it or not, I used a board of beautiful teak that I had lying around, a gift from a
friend who had it for years but could not bear to use it! Can you get more nautical than teak?) As you see here, it's cut
to length, slathered with a thin-mustard-consistency mix of epoxy and thickener, and clamped to the top edge of the hull,
along the sheer. The top edge of the strip is just even with the bottom of the bevel that we originally planed into the strake,
right near the beginning of the building process. See Day 7, if you don't remember. And, no, you can never have too many
spring clamps in a boat shop!
Here's a closer look at a section of the first layer of the sheer
clamp, glued and clamped into place.
And don't forget to give the top of the inside of the transom
the same treatment, just to make sure you can fasten the deck down to it as well.
Feb.
26, 2012 Day 19 The day before yesterday, we sealed the entire interior wood surface of
the hull with a coating of unthickened epoxy mix. It's no surprise that as this hardened, it raised the fibers of the wood,
leaving a somewhat rough surface. So, our first step today is to give it all a quick power sanding, with 100-grit (medium)
sanding discs. Of course, we remember to use the dust mask and to wear fully covering clothing.
After we sand inside of the hull, we suck up all the dust with
a shop vac. But that doesn't really leave it clean enough for what comes next, so we moisten a shop rag with denatured alcohol
and wipe it all down. That transfers all the dusty residue to the rag. By the way, don't be tempted to use a commercially
available tack cloth for this. Tack cloths are made of cheese cloth impregnated with varnish, and although that will be
effective at picking up dust, it will also leave a varnish residue that will interfere with later epoxy applications. So, what's
next? Use ordinary scissors to cut a 50-inch length of the fiberglass fabric that comes with the kit and lay it into the hull
from the permanent bulkhead going forward. Let the aft edge of the cloth climb up the bottom of the bulkhead by an inch
or so. The instructions say to cut the cloth so it overlaps the bottom edge of the side strakes by an inch or so. This
fabric has plenty of width, so I prefer to let it climb all the way up the side strakes and drape it over the top. Ultimately,
it will make a much neater job that way, with much less sanding required.
After the cloth is draped into place, carefully smooth it
into the corners and begin to brush unthickened epoxy mix into the weave. The cloth will want to shift as you start to do
this, so use your gloved hand to hold it in place as you brush. Because this weave is rather open, it easily absorbs the epoxy,
and there is no need to spread epoxy underneath first in order to get full saturation. (In fact, doing that will make quite
a difficult mess, so just let the glue soak in from the top.) As you can see, the fiberglass cloth becomes transparent as
the epoxy soaks through, exposing the wood grain. Follow up the brush work with a light squeegee action, using a plastic spreader.
Keep the spreader at about a 45-degree angle until you get to a dry section of cloth, then change the angle to almost flat.
You'll see that epoxy picked up by the spreader from tghe wet area will easily transfer well into the dry area, so you won't
need as much on the brush as you go into the next section. Here's a tip: there is a better-than-even chance that the disposable bristle
brush you are using will lose a hair or two as you use it to apply epoxy. If you see this happen even once, fish that hair
out of the epoxy with your gloved fingers, throw away that brush and unwrap a new one! These brushes are really cheap, and
when they shed a hair they will shed several more in short order. It's false economy to keep using a tired brush. Just
my opinion, of course. By the way, you'll notice
that the inch of cloth that you allowed to climb up on the bottom of the permanent bulkhead will pucker in the corners and
at least two other places. When you see these puckers, use a pair of scissors to snip darts down through the middle of them,
then let the sides overlap each other and dab them down flat with the brush or your gloved fingers.
Here's the entire interior of the hull, with the fully saturated
fiberglass forward of the bulkhead and all the un-fiberglassed surfaces brushed with another seal coating of epoxy. To coat
these sections, use the same disposable chip brush you used for the fiberglass, then follow up with a disposable mini-roller
to spread the epoxy evenly and avoid runs, then smooth it all down with a disposable foam brush. Don't over-coat the still-wet
fiberglass at this point. Notice that the edges of the fiberglass sticking past the top of the side strake are not trimmed
yet. A razor knife will make quick and neat work of this job tomorrow, after the epoxy is cured.
We finished yesterday by taping all the seams. I forgot to
say so, but we also taped the joints between the aft bulkhead and inside of the hull, both on the cockpit side and in the
hatch compartment aft of the bulkhead. Today, as shown here, we'll start by using the sander to "feather" the raised
edges of the tape into the surface of the adjacent wood. I know this will sound like a scratched record, but WEAR THAT DUST
MASK! It's even more important now than before, because today, the dust we will be producing will contain cured epoxy resin
and lots of actual fiberglass. You do not want this stuff anywhere near your lungs. Also, this dust is very irritating to
your skin. Wear gloves, wear a long-sleeved shirt, wear long pants and wear shoes and socks, not sandals. When you are finished
working for the day, throw all your clothing into the washing machine in a separate load from everything else, especially
any underwear belonging to you or the people you live with! When you feel the itch (and believe me, you will feel the itch)
you will know what I mean!
Next, mix up a batch of about four pumps each of the epoxy resin
and hardener, and use a small disposable foam roller to coat the entire inside of the hull, following up with a disposable
foam brush to "tip out" the epoxy and make everything as smooth as possible. Do a small section at a time, and brush
back into the edge of the previous section. The aim is to seal the wood with epoxy. Ultimately, you'll be laying down a covering
of fiberglass fabric in the cockpit area, but not the rest of the interior of the boat, so you want to make sure everything
is well protected from water.
If you've been following this builder's log, you already
know that I plan to depart in some places from the instruction manual provided by Chesapeake Light Craft with the kit. You
may recall the first change: using solid mahogany for the transom rather than the the thin plywood piece that came with the
kit. Now, it's time for my first major change in building process. First, a few words about what we are told
to do, and why we are told to do it that way: CLC wanted us to "tack weld" the assemblies for the hull and
the deck separately with dabs of glue in strategic places along the strake joints, one dab between each pair of copper wires.
Then, before the glue cured, we are supposed to wire the deck assembly to the hull and tighten everything up, without glue, so
that when the glue in the separate assemblies hardens the hull and the deck will be permanently shaped into their final forms,
and will therefore fit perfectly together when we finally attach them with glue. Then, when the separate assemblies are cured,
we are instructed to cut the wires, separate the hull and deck, apply "fillets" of glue to the seams, and then
glue down fiberglass tape to reinforce all the joints. I've done it this way twice, and while it does force you to work faster and
get the building done and over with sooner, it seems a little frantic to me. I have noticed that there is significant flex
in the separate hull and deck assemblies, and I am confident that even after each of them has cured into the final form they
will be able to mate perfectly with each other -- especially because I plan another major departure from the prescribed process
a little later. So, I am going to concentrate on the hull and deck separately from each other, making sure I do a perfect
job on each before joining them. I won't be wiring them together at all, not now and not later. Follow me as I build, and
you will see what I mean.
So, on to the next step: applying
the 3-inch fiberglass tape to all the seams in the hull assembly. Some builders say you should lay the tape out, then use
a bristle brush to dab unthickened epoxy onto it until it is saturated enough to turn clear. I prefer this way instead: First,
cut all the lengths of tape you will need and set them aside in an order that you will remember. Next, brush a coat of
unthickened epoxy mix along the keel seam from the bow to the bulkhead, making sure to go out about 2 inches to either side
from the keel line. Then, lay the correct piece of pre-cut tape into the wet epoxy along the keel line and brush more epoxy
over it. I find it gets saturated much more easily when the glue soaks into it from underneath and from the top, and you don't
have to poke at it with the brush to force the glue into the relatively tight weave of the tape. It makes for a neater and
faster job, in my experience.
Do all the other seams in the same manner, making sure that
the tape becomes saturated enough to turn transparent. If it's still white in a few places, it won't bond well to the wood,
and you'll have a blister there. You can use your brush, or a plastic spreader to get complete saturation, but I have found
nothing works better than a finger (protected by a disposable glove, of course). By the way, if you look carefully, you'll see a thread of fiberglass hanging down from the end of
the tape. Leave it alone until it cures, then snip it off with a pair of scissors or a razor knife. If you try to pull it
away while it's wet, you'll distort the weave of the tape and make a total mess. So leave it be!
This is how the outside of the hull looks after I removed all
the copper wires. I also removed all the temporary forms once I took all the other copper wires out and felt confident that
the glue alone would support the parts that make up the hull. Of course, I left the permanent aft bulkhead in place.
The next step is to clean up the inside of the hull in preparation
for covering all the seams with 3-inch fiberglass tape. I used a combination of hand-sanding and an electrical disk sander
for this operation. Yhis makes a lot of dust, so it is critical to remember to wear the sanding mask, and not a bad idea to
wear a shop apron as well.
The disk sander does a good job smoothing things out. In some
places, especially in the bow and stern, I can't get the sander to reach. In those places, I use (very carefully) a Dremel
tool to reach the lumpy places. A Dremel tool is a motorized rotary tool that looks and works sort of like a dentist's drill.
I use a rubber sanding drum attachment with a course ring of sandpaper over it. This tool can wipe away a lot of material
in an instant, so you have to use it with a very light touch if you don't want to go right through the hull. Once again, USE
THE MASK!
I took a day off after the workshop, so now it's back to work.
This is how the hull looked at the end of the workshop. I decided to lay down a bead of thickened epoxy, filling all the joints
between the strakes. I'm really not too concerned about embedding the copper wires, because I know a neat trick that will
allow me to pull them right out, even after the epoxy hardens to a full cure around them.
Time to pull the wires out. The first step is to snip them on one
side of the twist (NOT BOTH SIDES!!!) on the outside of the hull. For now, just snip the wires that go though
the single holes. Leave the double-hole wires alone at this point, so the temporary forms and permanent bulkhead stay in place.
Here's the secret: a barbecue lighter and a pair of pliers. I heat
the snipped wire with the lighter, taking care to hold the flame on the thick twist of wire about a half-inch away from the
hull, for about 5 seconds. If you count "one thousand one, one thousand two, one thousand three" and so forth up
to five, you'll be pretty accurate. The copper wire is a great heat conductor, and the heat it carries back along its length
will soften the epoxy around it just enough to let you pull the wire out without breaking it. Use the pliers (not your fingers;
remember, the wire is HOT). Use a scrap piece of plywood as a fulcrum to lever the pliers over, then grip the pulled out wire
a little closer to the hull and repeat, until the wire is all the way out. If you feel resistance, stop and heat the wire
up again. Despite all the care, there's a good chance you will break an occasional wire. If that happens, grip the stub end
of the wire poking out of the hull with the pliers, and apply heat to the pliers, then try pulling again. If that doesn't
work, flip the hull over, and grab what's left of the wire from the inside, using the pliers to grip through the softened
epoxy, and yank it out that way.
Feb. 19, 2012 Day 14 This
is the day that I held the boat building workshop on the floor of the Teaneck General Store. Scroll up to the News Flash box
near the top and click on the "Boat Building Workshop" link to read the article in the Bergen Record about that
event.
Yesterday, I left the stern open. Today, I'm going to install
the transom. It's a moment of truth: will the flare angle that I estimated turn out to be accurate, or will I have start over
again and cut another piece of mahogany? So far, it seems to fit, but I won't know for sure until I squeeze the other side
into place.
Notice that I've used bits of scrap plywood here to protect
the hull from the temporary screw heads, and that I've wrapped the scraps in package-sealing tape. By the way, I have found
that 1-inch sheetrock screws work well for these temporary clamping tasks. They are inexpensive, they grip well and I don't
mind throwing them away after a single use.
And here's the other side, ready to be squeezed into place.
I'll resort to the water bottle here, and let the wood get nice and soft before I make an attempt. If I do it dry, there's
a good chance the wood will break, or wires may pop out elsewhere.
It fits! By the way, at this point I have used no glue on
the transom. So far, all I want to do is make sure it fits, and make sure the screw holes are in place so that when I spread
glue later I can easily find the proper position. Nothing's more difficult than trying to position something the first time
around when it's covered by slippery, wet glue!
As I'm inspecting the hull for other problem areas, I see several
places where either the side strake overlaps the garboard strake or the other way around. That's not right; they should butt
up against each other so the final joint is flush and level. I have to find a way to pull the two panels into proper alignment,
so I make a sort of a "button" to do the job.
Each button consists of three parts: the tape-wrapped square
of quarter-inch plywood, a 3/4 x 3/4-inch wooden block (also covered with tape) and a 1-inch sheetrock screw.
But before I screw in the button, I make sure to drill a pilot
hole right on the joint, using a drill bit slightly smaller than the diameter of the screw. If I neglect to do that, the screw
will force the strakes apart at the joint, which will interfere with a tight fit. The pilot hole allows the screw to go in
freely, maintaining the proper alignment between the strakes.
Here's the block part of the button clamp, on the inside of
the hull. When the screw is tightened, it forces the strakes to line up flush with each other, which is exactly what I want.
And don't worry about all the holes we are putting into the hull. They will be filled with a putty mix of epoxy and mahogany
wood flour later in the process, and in the finished boat they will be nearly invisible.
Now, we're ready to start stabilizing the hull. We'll need
the supply of wood flour, the epoxy resin and hardener, a mixing stick, a cup for mixing, a plastic putty spreader, a 2-inch
chip brush, and an acid brush. Oh, and don't forget to wear the disposable gloves! By the way, did I mention
how boat-building is good for your diet? Well, it is: I have found that the best, cheapest epoxy-mixing cups are cleaned-out
yogurt containers. So, I eat a lot of yogurt! Chobani is my favorite, in case you forgot to ask. Not only does it come in
a very convenient size cup for epoxy, it tastes good, too. The yogurt, I mean. The best source I have found for plastic
spreaders is Harbor Freight: http://www.harborfreight.com/20-piece-4-inch-putty-spreaders-96088.html
The first thing we'll do is glue up the transom. I'll start by mixing
up four pumps each of epoxy resin and hardener in the cup, stirring for at least a minute until I'm sure they are well mixed.
By the way, in case I didn't say so earlier, you're better off if you squirt the resin and hardener in turns, instead of four
pumps of one and then four pumps of the other. That's because the resin is more viscous, and the pump tube takes time to return
to its "ready" position. If you halp it by pulling it up, there's a good chance the next squirt will contain a gob
of air, and your proportion will be wrong. After the epoxy is mixed, start stirring in wood flour, a bit at a time.
(Don't use your gooey mixing stick to dip into your nice clean bucket of wood flour, or pretty soon you'll have a contaminated
pile of chunks that won't do you a bit of good.) Mix in enough wood flour to make a mixture the consistency of mustard, slightly
on the runny side. Then, back the temporary clamping screws just a bit from one side of the transom, letting the hull spring
out by a sixteenth of an inch or so, and use the acid brush to work as much of the epoxy mixture as you can into the opening.
Tighten that side back up until you see some of the glue squeeze out (but don't crank it down so tight that you squeeze it
all out), and follow the same routine on the other side.
After you tighten both sides of the hull-transom joint, check
the outside of the hull to see if any glue has squeezed onto the outside of the hull. If it has, wipe it off now (with a paper
towel), because anything that hardens where it shouldn't be will have to be sanded off later, and it's not all that much fun
sanding cured epoxy. By the way, see how this glue has seeped down onto the piece of scrap plywood? You can bet that some
of it has managed to work its way down between the scrap and the hull, and now it's time to be thankful that you remembered
to wrap all these temporary scraps in package sealing tape! You did remember, didn't you?
After glueing up the transom, add a bit more wood flour to the
mixture to thicken it to the consistency of slightly loose peanut butter, and work it into the seams between the planks. If
you see any planks that have sprung slightly out of position, make sure to pinch them back to where they belong, because once
this glue cures... well, you get the idea. Try not to embed the twisted wires in the glue, but as you'll see later, there's
a neat trick for freeing them up if you do.
We're almost finished for this day, but before we turn out the lights,
we'll temporarily check to see how the deck assembly will fit onto the glued-up hull assembly. Assuming we've paid close attention
to twisting all the copper wires tight and to making sure that all the joints meet where they should, we should have
a pretty good fit. I use stretchy plastic wrap that comes in a roll from Staples to bind everything up. Doing that helps keep
the hull in the shape it should take as the epoxy mix cures, so that the final mating of the hull and deck will go smoothly.
Feb. 17, 2012 Day 12
Yesterday, we added the side strakes and closed up the bow.
Today, we'll start thinking about the stern, shown here, and identify a few problems in the hull shape.
One thing I've noticed is that when I tightened all the wires,
the bottom strakes have nut pulled up snug against the bottoms of some of the forms. I know from experience that if I leave
them that way, I'll have problems later getting a tight fit between the hull and the deck assembly. So, now it's time to sit
in the figurative groaning chair for a bit and think of a creative clamping solution. A couple of blocks, cut from
3/4 x 3/4-inch stock should fix the problem. Cover them with package-sealing tape, because we don't want them to be permanently
bonded, then screw them into the bottom of the form.
Here's what the form looks like from the other side, showing
the heads of the screws that fasten the clamping blocks in place.
Next, carefully flip the hull over and screw down through it into
the clamping blocks. Notice that I've protected the hull from the heads of the wood screws with scrap pieces of quarter-inch
plywood. Notice, too, that I've wrapped the scraps of plywood with package-sealing tape, because I don't want them to be permanently
bonded to the bottom of the boat if any glue squeezes out in a later step. As I tighten the screws, the bottom should come
into contact with the bottom of the form.
We finished up Day 10 by loosely stitching up the bottom panels,
which are also called the "garboard" strakes. Then, we added the temporary forms and the permanent aft bulkhead,
which helped give the hull its characteristic shape. Today, we'll add the side strakes, making sure that the bow and stern
ends don't get mixed up, and making sure that the "good" side (without the fiberglass tape over the puzzle joints)
is on the outside.
But before we hang those side strakes, we'll close up the bow
end of the garboard strakes. The thin plywood has enough flex to let me put in a few loose loops of copper wire, and
I know that there is so much twist and stress here that I'll need to drill a few more holes for extra wires to distribute
the force.
Time to resort to the water bottle again: give the bow area
a good soaking, inside and out, before trying to tighten up the laces.
Let it sit for a few minutes, until it's flexible enough so
that a spring clamp will squeeze it together. Then, tighten up the wires, remove the clamp, and we have a nice sharp bow.
We ended yesterday with the bottom panels laid out next to each
other along the keel line. Now, we'll match them up, inside-to-inside, and start stitching them together with loosely twisted
copper wires. At this point, use only the sigle pairs of holes; save the doubles for a later step. Also, we'll loosely stitch
the bow at this point. The bow will be very difficult to force together later if we don't get it wired up now.
Now, we take out the four deck forms. The aft bulkhead, shown
here, is the only one that will be left in place in the finished kayak. It separates the cockpit from the watertight aft hatch
compartment. The other three forms are armatures to temporarily support the hull until all four panels are wired up and glued
together.
The hull begins to take shape when we flip it over and start to
wire the aft bulkhead into place. Cut these wires long, 7 or 9 inches, because you want to leave the twisted loops very loose
for now (but twist the ends tightly enough so they are secure). As you can see, you run the wire through the upper hole in
the bulkhead, then run the two ends through the pair of holes in the bottom panel. Twist the ends together outside the bottom
panel. Don't forget, if you have covered the holes with fiberglass or epoxy, you may have to open the them up again with
a 1/16-inch drill bit.
Here's what the hull looks like from the stern, with the aft
bulkhead loosely wired into place. You'll notice that the stern, unlike the bow, is not wired at this point. You'll see why
in a minute.
Remember, when I posted the picture of the transom that came
with the kit, I said I wanted to use that as a pattern to create a more substantial transom out of half-inch mahogany? Well,
here it is, beveled to what I anticipate the flare angle of the hull will be at the stern, and ready to put in place. And
THAT's why the stern is left open for now.
Here's what the bottom looks like, all stitched
up and with all the forms in place. Tomorrow, we'll add the side strakes. By the way, here's some more nautical lingo: the
strakes along the bottom of a boat, nearest the keel line, are called "garboard" strakes. Feeling salty yet, Cap'n?
We've tightened up most of the copper wires, but there are some
areas that I know from experience have a great deal of tortion stress. We deal with stress in the usual manner: we break out
the bottle. No, not that bottle; the spritzer, with water.
And we give the area a good soaking, outside and underneath too.
Works like a charm: we have our way with the wood, and get a nice,
tight joint.
We're finished stitching the deck assembly, so we have carefully
set it aside and started work on the hull. Here are the two bottom panels, laid out with the inside (the side with the fiberglass
tape on the joints) facing up. It's a busy day
with other things, so we'll call a halt to the boat-building until tomorrow.
Today's a big day! We'll start stitching all the parts together
with short lengths of copper wire, and watch the boat take on its design shape. We'll need: the coils of copper wire that
come with the kit, a pair of wire cutters or stout scissors to cut the lengths, a pair of pliers to twist the wires, a roll
of package-sealing tape (more about that later), the temporary forms that come with the kit, and a sanding block to get rid
of those pesky nibs. We can start with either the hull or the deck assembly, but here I've chosen to start with the deck,
so those are the parts you see laid out.
First, we're going to depart a little from the CLC instruction manual.
We're going to trace out the oval shape of the hatch cover opening on the stern deck now, because it's easier to do this when
the deck part is laying flat than later, when it will be slightly curved. Take out the package of hatch parts that came with
the kit, and locate the hatch spacer. It's the outer ring in the group of concentrically connected parts. Snip it off and
sand off the inner and outer nibs, making sure that you have a nice, smooth inner surface.
Snip off two 7-inch lengths of copper wire. With the "good"
outside of the deck facing up, locate the two pairs of holes in the aft deck, and feed the wires through those holes from
the underside, so the ends are sticking straight up. Then feed them through the corresponding holes in the hatch spacer ring.
Next, use a pair of pliers to twist the ends of the copper
wires so they begin to tighten the spacer ring against the surface of the deck. You will be doing a lot of twisting as you
build this boat, and this is a great place to practice. Pick your favorite direction to twist, clockwise or counter-clockwise
(probably depending on whether you are a righty or a lefty) and stick with that direction throughout construction. Use the
pliers to pull up on the wires as you twist them, making sure that you don't leave slack underneath. You want to make everything
good and snug, but if you make it too tight, you'll break the wire and have to start over again with a fresh wire. Then, use
a sharp pencil to trace the oval shape of the inner edge of the ring onto the deck surface.
Here's the scribed line. Snip the wires and remove the hatch spacer
ring. Put it back with the package of other hatch parts; you'll need it later.
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Everyone who does this tends to develop strategies as they go
along. Here's one of mine: As I feed the wire through the holes, I have often been frustrated that they would pull
right out again before I had a chance to put a few twists in them with the pliers. Now, I just make a quick bend in each wire
end after I feed them through the holes, and that prevents them from slipping out.
After wiring up the forward and aft sections of the deck, and
snugging them up, I start attaching the sheer strakes with loosely twisted wires. I start amidships, then put in a wire
at the bow and at the stern, just to keep the parts from flopping around too much. Then I begin to fill in, working from the
midship area out toward the bow and stern in turns. Don't twist them tight just yet. Notice that most of the
holes are single holes, but some are double holes. For now, skip the double holes; these are for attaching the temporary deck
forms in a step coming up soon.
After all the wires are in place connecting the sheer strakes
on both sides to the deck assembly (using just the single holes), identify the temporary deck forms: the bow, the forward
deck, the aft deck and the stern. Cover the edges that will come into contact with the deck with package sealing tape. This
will prevent them from becoming permanently epoxied to underside of the deck. Remember, these are temporary!
After taping up the edges of the forms, screw the straight edge
of each of them to a scrap stick of wood, about 3/4-inch by 3/4-inch, just to keep them rigid as they are wired to the underside
of the deck. Note that they don't need to go all the way across, and you need to make sure that they don't cover the holes
where the wires will go. It will make things easier if you run a 1/16-inch drill bit through the holes where the tape is covering
them up; otherwise you have to poke the copper wires through the tape. It can be done, but it's much easier to drill through
the tape first.
Wire the forms into the holes in the deck and sheer strakes.
Now you see what the double holes are for. Again, keep your twists loose for now.
Here's the deck and sheer assembly, upside-down, all loosely
wired together with the deck forms installed.
Next, we carefully flip it over so it's right side up, then
start twisting the wires tight. Use pinching pressure with your fingers to make sure all the bevels meet properly as you twist.
It's best to twist a little, then go on to another wire, to avoid over-twisting and breaking a wire. Remember, you are exerting
a great deal of tension to make the wood bend into shape. Also, too much twisting, too fast, all at once, will heat up the
wire and cause it to break. So, take it easy, go around the work gradually, and bring it all into shipshape form.
If you do it properly and carefully, almost all the beveled
joints will meet neatly.
No matter how careful you are, however, there will still be
a few places that just won't come together. Working on the port side, I count five spots that could use an extra twist of
wire, so I use a pencil to mark places to drill new holes. I'm pretty sure that extra wires will help a bit, but even if they
don't make a truly tight joint they will certainly take some of the stress off neighboring wires and keep everything shipshape
until the deck assembly can be glued into its final form. Any small gaps can be filled later, with a putty made
of epoxy and some of the wood flour that CLC sends with the kit.
Here's the starboard side, which we haven't tightened up
yet. It's getting late, so we'll leave that for tomorrow, when we'll also stitch the hull parts together.
When we're finished sanding, we'll bevel the edges of the strakes,
following the beveling plan provided in the instruction book. The first tool we'll use for this is the low-angle block plane.
By the way, when you set a plane down, rest it on its side,
not on its sole. That will avoid any damage to the sharp edge of the blade.
Before we start beveling, we'll have to plan ahead. It's a good idea
to mark the ends of the insides of all the strakes with an "S" and a "B" for "Stern" and "Bow,"
just so we keep things in their proper position. The inside is the side that will be on the inside of the completed boat,
which is the side that we used the fiberglass tape on when we glued up the puzzle joints.
Study the parts layout carefully to make sure you mark the correct
ends of the strakes. Pay close attention to the direction the fingers of the joints are depicted in the layout. Double- and
triple-check! You do not want to get this wrong!
Next, study the beveling diagram carefully. Note that there
are two basic angles that we will be using: a 45-degree angle for most edges, and a far more acute angle where the strakes
join at the bow and stern. But the most critical question is: which side do we bevel? Make your own rough sketch of a cross
section of the complete kayak and draw lines at the joints, like I've done here. Basically, you want to make mitre joints,
and as in all mitre joints, you want to leave more material on the outside of the finished project than on the inside.
So when you bevel, make sure you are shaving on the inside of the strake, the side with the fiberglass tape and your "B"
and "S" markings.
Beveling is a straightfoward process on the edges that are either
flat or somewhat convex, using the sharp low-angle block plane. Just make sure to take smooth, sweeping, gentle strokes,
and don't cut into any material on the outsides of the strakes. But on the edges that are concave, especially on the pointy-ended
sheer strakes, the flat surface of the sole of the plane will prevent us from getting to the material that we want to shave
away to create the bevel. Some people use a spokeshave for this. (That's the tool in the background.) I find it easier to
reverse-wrap a quarter-sheet strip of 80-grit sandpaper around the curved TOP of a rubber sanding block (shown in the foreground) and
use it to make the bevels in the concave curves. This plywood offers little resistance to the sandpaper, and I find it goes
quickly and with great control.
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NOTE As you are beveling the edges, note that the 45-degree bevels cut through all
three plies of the plywood and leave a sharp edge on the side you have identified as the outside of the strake, but the flatter
bevels at the ends of the strakes cut through only two of the three plies, leaving the outside ply unbeveled, with a thin
butt edge. While this is not mission-critical, and taking off a sliver or two more than you should is nothing to get terribly
upset about, it is a good goal to strive for.
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As you are using the block plane for most of your bevels, you
should see nice uniform curls of shaved plywood coming out of the top. If you see chunks or chips, take the time to sharpen
the edge of the blade, and make sure it is adjusted to protrude just a touch from the sole. Time spent on tool maintenance
will save many times more time in construction, and you'll get a much better result as well.
There are quite a few brands of sanding disks available. Fairly
recently, Home Depot started carrying these Diablo disks. I like them a lot, because they are incredibly long-lasting, quite
economical in packages of 50, and they have a hole pattern that will fit any hook-and-loop disk sander.
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