Box Beam Strongback

As if two projects were not enough, I am embarking on yet a third project - the Guillemot Double Kayak.  The Guillemot Double will be a stable, roomy kayak for Renee and me to play and camp with.  At 20' long, it will be relatively fast. It is strip built, and looks like fun project.

The first step in this process is the strongback.  The strongback is a 17' 11" 2x4.  Dimensional lumber isn't stable enough, so I built a box beam strongback out if 1/2" ACX.  It used roughly 5/8 of a sheet of plywood.

I cut the plywood into five 2 7/16" widths and five 3 15/16" widths.  The wider strips were rabbetted on the edges to accept the narrower strips.  The ends were tapered according to the plans.  See The Strip Built Sea Kayak by Nick Schade for more information.

 
 
 

Learning to tie my shoes

Finally, at the age of 47, I have learned to tie my shoes.  No, really tie my shoes.

Last Thursday (4 days ago), I reached down and tied my shoes again.  I wear boat shoes so I can slip them on and off, but still they tie, ideally, not often.  I have to tie my shoes every hour.

At that point the light bulb went off:  I remembered reading on the great Animated Knots by Grog site that the shoelace knot is a square knot.  Now, I had never given any thought to my shoelace knot.  I just tied it when it needed it, but now I am tired of tying them every hour.  So I examined my shoes.

Granny knots!  Ugh!

No wonder they constantly came untied, and every bow I tied was twisted and ugly.  Now to figure out how to fix it.

Simple.  I tied my shoe, and paid attention to the start.  It was a granny knot this time.  Then I tied it again, pausing to reverse the start (the lace on top becomes the lace on the bottom).  Bingo!  Square knot.  I tied both shoes.

So why am I posting this on Monday, 4 days later?  Because this is the first time since then I retied my shoes.

For more info, see the Grog's site, or Ian's Shoelace Site by Ian Fieggen.  There you will learn about far more than knots.

Kindergarten teachers - make your life easier.  Learn this knot the right way so that the 1 or 2 kids in your class without velcro clasp shoes won't need you to tie their shoes more than once a day.

Test Launches

On Sunday, October 26, I took the canoe out for a test launch with the boys.  The canoe is not yet finished.  It has two coats of primer outside, and will receive two more.  Fairing is needed inside.  The breasthooks are not installed, although thwarts are installed at the breasthooks.  After all of that, it needs paint.  We are taking it out because it is ready enough, and we don't want to wait until next spring.

Renee wanted to go, but her work schedule, combined with a little car trouble, bumped her to another trip.  Not only was this a test launch for the canoe, it was a test for my redneck conoe rack assembled from 2x4's and sheetrock screws.  The rack worked well, by the way.

My crew for the day.

The launch site was  Lake Crabtree County Park in Cary, NC.

View Larger Map

I had the boys paddle out for pictures.  These two pictures look calm and peaceful as the canoe makes a turn back to the beach.  The actual scene was much more chaotic as they learned that side-to-side motions in a round bottom canoe cause a lot of tipping.  No one got wet, and no water was taken aboard.

The best picture we'll have until it is painted.

The weather was very calm, as you can see.  We paddled the length of the lake, beached the canoe, hiked a few hundred feet of the greenway there, and found a spinning reel on the beach.  It worked.

I went back out Monday with Renee and her friend Nikki from work.  Another calm day.  We paddled the length of the lake again.

This canoe feels tippy because of the rounded bottom, but has good secondary stability.  It won't capsize or take water unless you panic, or are trying very hard.  The tracking is excellent.  It paddles easily, and two paddlers can achieve good speed.  It steers easily.  If you are considering building a canoe, I would recommend this one.

Outside Fairing Done, Priming Begun

It seems I have been fairing forever.  For the last month, I have rushed home from work everyday, carried or rolled the canoe out into the driveway, and sanded.  And sanded.  And sanded.  Then, I wiped down the entire canoe, a dried it.  And then, mix up a batch of fairing putty (a sort of bondo for boats), try to spread it all out where it is needed before it is too stiff, and even spread some after it is too stiff.  Everyday. And this is the outside only.  The inside will come later.

For fairing the outside, I used blended filler of microballoons and colloidal silica in epoxy.  The microballoons are very fine, and so is the silica, so I wear a good respirator for mixing, fairing, sanding, and cleaning up.  At first, I purchased blended filler from BoatBuilderCentral.com, but after I discovered how much I would need, I mixed my own.  It's cheaper.

A lot of fairing has been required to cover up my early  mistakes.  I had misaligned the panels in several places.  I built up the hollow areas in several layers.

Covered in fairing compound.

Staying safe.   The dust is fine, and contains silica.

Now that the fairing appears finished,  I am going to prime the outside to seal the fairing in anticipation of a test launch of the canoe.  I am using System Three Silver Tip Yacht Primer.

I applied two coats of primer (so far) with a foam roller.  I used the Whizz brand from Lowe's.  Two rollers were required to roll on a full coat of primer onto the canoe. The primer went on well.  I rolled and tipped (probably not necessary, but it didn't hurt).

Priming exposed a few imperfections I will fix later.  Here is the primed canoe.

Tie Down Holes

I asked for ideas on the bateau forum on how to include tie down points in my canoe.  I received many good suggestions, and they guided my design.

Some suggested a handle.  I did install a handle.  It is for carrying, not tying down.

I settled on holes through a glob of putty. I wouldn't call it an endpour. Each blob is only 3 ounces plus wood flour. I did not care about how the blob looks because I am going to hide it with foam under the breasthooks.   Above, you can see the cleats for the breasthook.

First, a 5/8" hole 1/4" to 1/2" inch behind the end fillets. 

Then I inserted a 1/2" OD PE tube as a form.  I chose poluethylene because it retained its round cross-section, which vinyl tubing does not.

I globbed 1 1/2 ounces of putty (falf of a batch) around the tube on each end, making sure it squeezed  out past the tube to the outside of the canoe.  After it hardened, I put another half batch on to caver the tube well.  I only have a picture with half of the putty on. 

A few days later, I gripped the tube, twisted hard, and pulled it right out, leaving behind a glass smooth tunnel through the end.  I dressed the hole with a bevel.  I will graphite the interior, not because it is necessary, but because it will look good. 

Here, you see it in action.

The Work Cart

Until now, I have been workin with the canoe on a pair of sawhorses.  I like to sand outside.  Getting the canoe in and out of the garage by myself is an ordeal.  Then the final straw - the sawhorses are never the right height for comfortable work.  After sanding the underside of the rubrails, I spent the next day moving gingerly because of back spasms.

I needed a cart.  The requirements?  It has to be capable of supporting the canoe (16') and the D4 dinghy (7 1/2').  It has to roll in and out of the garage.  The height has to be adjustable 24" to 40".  It has to be stable and sturdy.

After a couple of trips to Lowe's for 2x4's, sheet rock screws, castors, and dowels, here is the result, nearly finished.

The uprights are two 2x4's with a sliding 2x4 in between.  The height is set with 2 dowels in each upright.  Working is so much more comfortable now.

In the picture below, it is finished.  The bracing makes a handy lumber storage rack.

Beginning the D4

I'm working on the D4 again, after 9 years.  I was at a waiting point in the canoe, so I stitched it together with my son, Alston.  He has watched me carry the parts for this boat around the entire time, so he was excited to help.

Recapping what was done 9 years ago,  I cut out all of the panels and the frames.  The panels are a luan plywood, and the frames are AC.  The transoms are 3/4" laminated from 1/4" plywood.  I wanted the option of putting a small motor on it.  I misunderstood the directions and laminated the bow transom as well.  I added an extra pound or 2.  Oh, well.

I am stitching it together with tie-wraps and 3/4" dowels.  I started by screwing the panels to the frames, mid-seat bow fore frame first, stern transom second, bow transom third, then the rest.  We loosely stitched the pieces together.  We will tighten, adjust, and tack the seams later.  Alston came in especially handy, since he crawled under that tiny boat, and fed the tie-wraps back to me.

Side view, through my work cart (next topic).

Front view.

Rear view.  Notice the daggerboard trunk halves, coated on the inside with graphite and epoxy.  These have been done with left over epoxy.

Making the Yoke

The yoke as designed for this canoe was a simple 2" dowell.  I wanted more flair, so I came up with a wavy yoke.  I suppose it is not technically a yoke, since I won't carry this canoe on my shoulders, and it is not designed for that purpose.  It ended a little oval, 1 1/2" x 1 3/4".

The yoke began life as 2 pieces of 1x4 poplar, glued up into a 2x4.  I couldn't see carving a harder wood, such as oak, at least not the first time.

I laid the curve out on the board every half inch.  The curve is just 1 1/2 cycles of a sine wave, calculated on Excel, with a 1/2" foot for mounting.

The shape was cut out, square, with a jig saw (I wish I had a band saw).  If you look carefully, you can see that the octagon has been marked, and the part to be removed shaded with a pencil.

I removed the shaded part with a shaper, a cheese-grater for wood, leaving a rough octogon.  Most of the material to be removed has been removed.  Only a little material has to be removed from the remaining corners to end up with a round form.  Being poplar, it was very easy to remove material.

I did the final rounding of the corners with a 1 1/2 wide, 100 grit sanding belt from the bargain bin at the Klingspor woodworking store.  Drawing the belt back and forth, like polishing a shoe, quickly rounds the wood.

It may not look like it, but this yoke is 35 1/2" long.

I used clamps when I glued it in.  If I did it again, I would use screws through the rubrail.

The Seats

The seats for the canoe as designed are open bottom - a piece of plywood over 1" cleats and supports.  I didn't want to leave it open for various reasons - it would be a hiding place for spiders in storage, it would be a pain to clean, and I wanted to experiment with floatation foam chief among them.  So I added a plywood bottom with foam in the middle, providing about 17 pounds of floatation for gear or provisions.  This complicates assembly, because the frame has to be installed after completion instead of being built in place.

After measuring the seat dimensions, I started with the frame on a piece of plywood.  The visible parts of the frame are from scraps of red oak that I have had for 12 years, bullnose trim  left over from stairs I built in a house I used to own.  The newels on those stairs were not loosely nailed to the floor, like in most houses.  They were screwed to the joists.  No one could crash through those rails.  The scraps were not long enough, so I joined pieces to make them long enough, using lap joints.  The hidden cleats were spruce.

This is a learning project, and this is my opportunity to learn about floatation foam.  I have had this flotation foam since 1999, but apparently floatation foam has a shelf life similar to epoxy.  It is still good.  Floatation foam is a Coast Guard approved, two-part polyurethane mixture that foams when mixed, like expensive Great Stuff™.  When mixing this stuff, the mixture is 1:1, so it is convenient to use identical disposable plastic cups (labeled A and B so you can re-use them for each batch) and pour each part to a line molded in the cups.  I mixed thouroughly, just until it started heating, and poured into the seat frame.  Below, you see the result of two pours on the bottom, and the other seat after trimming.  I trimmed using guitar wires, but it took four because they break so easily.

After filling with foam, I glued the plywood tops on.  The assembly is very stiff and light.

Mounting the seats was not as straight forward as I thought initially.  The plans had a measurent to the top of the seat on the centermost edge.  This measurement is different from the other side.  I used a level to make the seat as close to level as possible, smeared the ends thickly with epoxy putty, and screwed the seats into place using two sheetrock screws on each side maintaining 1/8" separation between the seat and hull.  I put 9 ounce woven fibberglass tape on the upper side, wet on wet.

Below, an installed seat.

Geezer Rock

Tonight Renee and I, along with several friends, checked out Arrogance at the Cat's Cradle.  Arrogance is the king of the Triangle bands.  There are probably 15 bands out there who would take exception with that statement.  Arrogance formed way back when - '69, I think.  They played together until 1983. They released 5 records, including Suddenly on Warner/Curb, plus The 5'11"Record long after the breakup.

They opened with "Not Unusal." That is one of my favorite Robert songs. Later, a great version of "Money'", but no "Open Windows."  I have to say I miss the old days when they walked onstage to the whistling song, and closed with "Puff, The Magic Dragon."

There were a lot of geezers there.  I'm not young by any means.  I can't remember JFK's death, but I do remember RFK's.  I would have been in the youngest 5% there, had so many people not brought their grandkids.

Attaching the Rubrail

Laminating the rubrail is a several day process.  The rubrail is made of three 1/4" thick by 1 1/2" wide plywood strips laminated to 3/4" thick.  They are glued on one layer at a time with a glue made of epoxy and wood flour.  You really need lots of clamps for even clamping pressure.

I don't have any 16 foot strips of plywood, of course, so my rubrail strips are 8 feet long.  I will stagger my joints for strength and for fairness of the curve.  On the last layer I will center the 8 foot strips on the sides and finish with 4 foot strips on either end.

I borrowed a few clamps to make 49 clamps total (thanks Rob and Carl).  On my 16 foot canoe, that is 25 per side, more or less, or one clamp every 8".  I glued on the first layer on both sides.  It bends vertically more easily than you would expect.  I used 10 ounces of epoxy for the putty to glue on 16 feet of rubrail.

After it set up, I noticed little waves in the rubrail.  There were depressions at every clamp point.  This picture shows it, although blurry.  The canoe is longer than the depth of field.

I was afraid to do only one side at a time, to avoid pulling the canoe assymetrical.  To try to correct the waves, I spread on the epoxy a little thicker and clamped over the high spot on the first strip.  This helped some: it reduced the waviness by about half.

Since the 2 layers has made the hull stiff, I decided to go ahead and put the last layer on one side at a time so I could use all of the clamps.  I used 44 clamps on each side - 1 every 4 1/2 inches.  This is a much better spacing.  I will make sure on future boats that I can clamp every 4 inches.

This is the finished rubrail, before shaping.

Taping the joints outside

My goal for this session of work is to tape the outside joints with fiberglass and do as much of the epoxy work as possible wet on wet.  I probably didn't say so earlier in this blog, but my real purpose in building this canoe is to learn for building a bigger boat.  Having a canoe at the end is a fringe benefit.

Yesterday I prepared for today's work.  I sanded the outside so that all of the epoxy was scuffed and new epoxy would adhere.  I rounded the joints outside to about a 1/2" radius with a belt sander.  After rounding the edges, I noticed several holes in the core of a couple of panels.

I had seen few voids from the cut edges, so I investigated closely.  I discovered tht I could push my thumb nail throught the veneer at these holes, across the panel, all of the way to the other edge.  I have to fill these to prevent rotting, so I got out the Dremel and looked for discolored lines or snall voids at the edges.  I routed through the veneer and first layer of the core.  I will fill the slots with epoxy putty, and cover with fiberglass tape to replace the lost strength.

Last, I laid out and cut the fiberglass tape.  Each piece was rolled like a scroll from each end to the middle, to make it easier to lay out, just line up in the center, and roll.  I laid them out, labeled.

I started early doing the outside joints.   The steps - prime the wood, fill the joints to make them smooth, and apply fiberglass tape.  Priming the wood is easy enough.  I used a foam roller.

I let the epoxy cure nearly an hour, then I mixed putty and filled in all gaps in the joints and all of the slots I cut to expose the voids.  As soon as I finished puttying, I began taping.  I taped the bow and stern (Which is which?), then all four chines.  I used  the scrap tape at the bow and stern between the chines to make fairing easier by providing a constant number of tape layers.  I also used a little woven tape to strengthen the slots cut over the core gaps in the plywood, since the plywood was only one layer thick at those spots.

I let the tape cure awhile, until it set.  Since I had time, I went ahead and filled in the weave of the biax tape with a thick wood flour/epoxy slurry.  It was closer to putty on the vertical surfaces.

Working wet on wet is definitely the right way to do this.  There is no sanding between steps, and that saves a lot of time.

Below, the canoe is all taped.

Flipping the canoe

I flipped the canoe over, and inspected the misalignment problem. It's easy enough to fix. My idea was to fill the depressions (4 of them) under the tape with epoxy/wood flour putty. fmiles on the forum suggested using strips of plywood bedded in putty as a filler less expensive than straight putty. I laid a strip of scrap plywood by the deepest spot, but it was too thick. But it was a great idea.

When I was butt splicing the panels together, I coated the bottom panels with leftover epoxy, so as not to waste it. These panels have little bend, so it didn't affect anything. But because it has cured, I have to sand for adhesion of the next layer.



I sanded quite a while, mostly smoothing down putty that squeezed through the joint from the inside. The putty spots are hard, jagged sandpaper-shredders. I prefer hand sanding: there is just something relaxing about it that quietens the mind and puts everything in perspective. I think I look forward to fairing. You can see in the picture how the 60 grit sandpaper has scratched up the smooth epoxy surface.

I spread epoxy putty in the depressed areas, as wide as the tape will cover. The idea was to build up the area under the tape level, and let fairing putty fill the space in between. 12 ounces of epoxy putty took care of the problem.

Unfortunately, in one area I took care of the problem too well. I built it a bout 1/32 inch too high. That would be a problem in fairing, and I certainly didn't want to sand through fiberglass tape. I knew this stuff is hard, but it hard to realize just how hard. 45 minutes of hard sanding by hand, with 3 paper changes, and I had it level. The high area was only about 6 square inches.

This is the result:

The upper panels

I began by removing the duct tape from the lower chines and bow. It all looked good, except for an area about 18-24" long where the panels were misaligned. As you can see, it is about 1/4" at its worst. This is just something to fix. An asymmetrical depression on the bottom will probably affect tracking.


I am not going to make the mistake of relying on the duct tape again. I drilled every 6-12" and used tie-wraps. The tie-wraps pulled the panels into alignment everywhere except about 6" form the ends. The upper panels wanted to pull inside the chine panels at those points, so I forced them into alignment with blocks. There is a trick using dowels or pipe under the tie-wraps. I'll do that next time.

Next I primed the area with epoxy, and let it sit a little while. Then I spot welded with putty between the stitches. In a few places I covered a tie-wrap with putty by accident, but later discovered that the epoxy won't bond to the nylon so I just pulled them out after cure. Of course, the upper chine is easier to fillet than the lower chine, being flatter.

After the spots were cured, I removed the tie-wraps, and made the fillets. I left the tie-wraps in the bow, and put the bow fillets in in 3 layers, shaping again with the back of a spoon.

I taped the joints while the fillets were tacky. Where I misplaced the tape, reseating it distorted the tape a little.

After the taping, this is how it looked. Notice, also, the panels cut and ready for the D4 on top of the entertainment center.

Attaching the chine panels

I set aside, or tied to set aside, a weekend for assembling the canoe. The plan was to start early Saturday morning, tape the chine panels to the bottom, prime the edges, wait, apply putty, wait, fiberglass, sleep, get up early Sunday, and repeat with the upper panels. Well, it was a nice plan.

Now for reality. Other responsibilities came up. But I did get a respectable amount done. First order of business - tape the seams. I tried to avoid using stitches for simplicity (I didn't want to fill holes). I used 3M low residue duct tape to tape the seams. It wasn't nearly as easy as it looked in the free canoe plans. Those tutorials were produced by professionals, and this is my first project. Quickly, what I learned:

• Start with short lengths of tape spaced 12" to 18" apart.
• After the shape is close, tape the entire seam, pulling it into shape.
• Most important, stitches are necessary. I used one stitch at the top of the chine panel on the bow and stern. I wish I had used them every 12 or 18 inches, closer in tight bends.

Next, prime the wood with epoxy and putty the joints. This is my first experience puttying joints. Tricky! Someone on the bateau forums suggested putting the fiberglass directly over the wet joints. This would probably save sanding the imperfect joints and spots of putty that are missed. This stuff dries like cement, and shreds sandpaper if you don't approach it slowly. Renee was a lot of help with the joints.


The hardest part to epoxy was the bow and stern. There is not adequate room to work. After trying to putty that narrow angle with a squeegee (messy) and my gloved fingers (more messy), I discovered the back and tip of a plastic spoon did an amazing job. I really dread sanding the mess I made in that area.



The next morning, I fiberglassed the inside bottom to chine panel joints and bow and stern joints. I put a thin coat of epoxy over the putty, and let it cure for an hour until sticky. While it was curing, I prepared the fiberglass tape by finding the center, and rolling to the center from each end, like a scroll. I carefully laid the fiberglass at the center joint, then rolled each way, lightly stretching the fiberglass as I went. The tackiness of the partially cured epoxy kept the tape in place. It also made realigning the tape a little messy. It would distort the tape a little to lift it.

I wet out the fiberglass using a 4" foam roller. It was a cool morning (for North Carolina), and everything went well. The Marinepoxy wet out the fiberglass easily. I used 21 ounces of epoxy (seven 3 ounce batches) to wet out 34' of biaxial tape. I thought that I did a good job wetting out the tape without over saturating it, but maybe I did too good of a job - about 15% of the tape was a little epoxy starved. It is fixable, though.

It looks like an olive boat now.


Next, the upper panels.

Cutting out the canoe panels

Thanks to a suggestion on the bateau forums (on another boat to another person) by a poster whose name I cannot remember, I decided to cut out all of the panels at the same time. Did I say thanks for that suggestion? It worked great. To do that, I had to nest the panels differently (sorry Jacques), and use four sheets of plywood instead of three. It won't go to waste, but if I were using $50 okoume instead of $11 lauan, I might stick with the original nesting.

The original nesting had two upper panels and a center panel on two sheets, and all four chine panels on the other sheet. I drew one upper panel, a center panel, and a chine panel on one sheet. I clamped four sheets of plywood in a stack, and cut all four of the chine panels and all four of the upper panels at once. Then I removed the bottom two sheets of plywood, and cut out the two center panels. As I cut the panels out, I kept the sets clamped together, and smoothed my rough spots with a belt sander. Ten panels for the price of three cuts. That's great, but the real benefit came next, when I glued up the 16' long panels.

The butt joints between panels were easy. All went just as the directions said, except that some of the pieces developed a twist or lift and did not want to mate willingly. I learned to hold the pieces flat the best I can, force a little putty between the ends, apply the fiberglass (which wet out very easily with the Marinepoxy), cover the joint with polyethelene sheeting, and weight with a 20 pound rock on top of a piece of 1/2" plywood to evenly distribute the weight. Wait 12 hours, flip the panels carefully, and repeat on the other side, no weight necessary.

After gluing I checked for symmetry by stacking the two upper panels and the two chine panels. I could not feel a difference with my fingertips. Once again, thanks to whoever made the suggestion to cut mirror image panels at the same time.

Materials

Happy Bastille Day!

I started the D4 back in 1999, and set it aside after cutting the frames and panels. I used 1/4" lauan plywood for the panels and 3/8" AC for the frames. The transom and bow transom were made of 3 pieces of lauan laminated with epoxy to 3/4". The lauan from that period was a stiff and good-looking plywood, although the center ply was thicker than the outer plies. The cut pieces were stored and moved around carefully. I can't say the same for the epoxy.

The epoxy was System Three epoxy purchased in 1999. It was stored in garages and storage units with temperatures in excess of 110 degrees in summer and hovering around freezing in winter. I was considering throwing it out and buying more, but after reading that epoxy has a very long shelf life, I tried it first. I am thrilled to say that after 9 years stored in bad conditions, the epoxy performed like new. The pumps had to be replaced.

Because I liked the lauan plywood I purchased 9 years ago for the D4, and because I wanted to build the canoe on the cheap, I purchased lauan plywood again. It isn't the same lauan plywood. The face veneer looks good, but the back veneer is ugly and full of knot holes. The veneers are very thin, and the wood has three equal plies inside. On the minus side, it splits along the middle ply. It bends like wet spaghetti. Still, I think the canoe will do what I need.

I'm using Marinepoxy for the canoe. It isn't as thick as the System Three. I have the medium speed hardener for both. In the heat of a North Carolina summer, neither allows much more than five minutes working time for a three ounce batch.

Beginning two boats - finally!

Years ago, in 1999, I ordered plans and supplies to build a small boat - Jacques Mertens's D4 dinghy. (The D4 has since been replaced by the D5 at bateau.com.) I had a garage then, but thanks to divorce, apartmentaliving, and long-distance dating, it was carefully put aside after I had cut the hull panels and frames out. Now that I am remarried and living stably with a garage (at least for the time being - until I move again), I pulled the parts and plans out, and picked up where I left off.

But wait! I like to canoe, and building a canoe looks quicker. Even with my schedule, I'll be able to get a canoe in the water before fall. So why not build a canoe first? I looked at plans on bateau.com where I had bought the dinghy plans, and chose the 16' Hiawatha. Progress on the D4 will slow, but Renee and I will enjoy the canoe sooner.