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Part 2

By William Watt, Ottawa - Canada

 

Part 1

Part two continued from yesterday...

Leeboards

My rudderless sailboats steer well until it comes time to change tacks. Then I have to use a paddle. For the canoe I made leeboards which rotate like rudders to help the canoe tack. They help but they are nowhere near as responsive as rudders hung off the stern. Leebords should be raised and lowered on different points of sail. Mine are fixed in the down position. That needs to be changed. I'm vulnerable to broaching capsizes when running downwind.

I like the turning posts. They are made from kid's bikes from re-Cycles. The tubes cut readily with a hand held hacksaw and were ground back with a half round file and with a stone wheel on the electric drill.

Leeboards - bikes from re-Cycles
Leeboards - posts from kid's bikes

I don't know the optimum size or shape for the leeboards. The ones I made probably have a lot more weight and drag than necessary. They are made from a couple of pressure treated fence boards I had on hand. The boards were cut in half and edge glued. Attention was paid to the crown of the wood to get some laminar flow but the outer edges have not been given any shape. Holes were drilled in the inner edges and filled with epoxy. Three inch finishing nails with the heads cut off were inserted in the holes. PL Premium was spread along the inner edges. The boards were held together with Spanish windlasses until the adhesives cured.

Leeboards - edge gluing

The leeboards are bolted to the steering posts where the bicycle brake calipers go and are held vertical by a nylon cable tie through a hole drilled in the leeboard. That should allow them to kick up if they strike anything solid. Unfortunately the deck keeps them from kicking up all the way. To mount the leeboards a plywood box beam was added to the front of the deck. The bicycle top tubes slide into it. The head tubes drop into cutouts in the deck to hold them in place. I forgot that leeboards have to be tied down or they will float up. After testing I added plywood gates to hold the leeboards down. The leeboards are also secured with line in case of capsize. I put a piece of hardwood dowel in the stems where the handlebars go, and a coil of stiff wire to tie off the leeward leeboard. Under sail the leeward board is fixed in place for lateral resistance and tacking is with the windward board. The stems are lined up so the leeward leeboard is parallel to the hull. At first a piece of non-stretch clothesline was used to tie off the leeboard with a caribanger clip. That was replaced with a stick with end hooks made from finishing nails. It holds the board steady and is easy to switch from leeboard to leeboard when tacking.

Leeboards - installing
Leeboards - installed

Bicycle head tubes are attached to the top tube at an angle, in this case 12 degrees, so the leeboard is vertical when the canoe is heeling 12 degrees. I read that cruising monohulls spend most of their time heeled at about 15 degrees, so with luck the lateral resistance on this canoe is vertical most of the time, just like the original Dutch leeboards.

In an attempt to increase effectiveness during testing shoes were made out of scraps of door skin (1/8" mahogany plywood). The ends of the strips were wired together. The shoes were spread over the ends of the leeboards and tacked in place with a couple of small screws on each side, all very temporary to see if it would improve steering but I didn't notice any. The tops of the leeboards boards were cut away for 360 rotation.

Leeboards - modified

Sailing Launch

Testing was done on the canal reservoir behind the Hog's Back dam and lock station next to the Rideau Canoe Club. Every few minutes the busy locks would disgorge cabin cruisers and take in more. The canoe club was crowded with kid's lessons. I had to keep a sharp lookout. Kids were yelling "Hey, look at the sailing canoe".

On cart at launch site

August conditions are quiet with calms between moderate gusts allowing plenty of time for thinking and making adjustments. Unfortunately the light conditions extended well into September. I never got to sit on the gunwales. I knelt on the bottom in the "U" of the deck with everything within easy reach. After getting everything to work with the small sail the larger sail threw everything off balance. The boat would not tack. When close hauled it crabbed sideways to windward. The shape of the hull is part of the problem. The leeboards need to be moved more toward the stern. I'll have things to work on next season.

Testing with small sail
Testing with large sail

Construction notes

1. Plywood:

The whole sailing rig can be cut from less than half a sheet of 4x8 plywood and a 2x4. Most canoes are 3 feet wide. A 4 foot wide deck will overhang the gunwales. The bulkhead was made from deck waste.

Made from waste
Nothing wasted

I used 1/2" exterior grade plywood because I had some. It wasn't stiff enough. It should be 3/4". I've made furniture with 3/4" and that's stiff enough. The plywood is all above water so it doesn't need to be marine. For stiffness two copies of the 1/2" deck were laminated with PL Premium. It's important to tack the corners together with finishing nails to keep the pieces from sliding around as the weights were piled on. The laminate was wrapped in plastic before the weights were added.

Laminating deck

The box beams were made from 1/2" ply, PL Premium, and screws. The screws hold the pieces together while the PL cures. I spaced the screws 3" apart. I buy screws cheap at the building materials recycle centre when available so I've always got a supply on hand. The bulkhead is 1/2" plywood. An extra piece was added across the top for stiffness but again, 3/4" would be better. The plywood got one or two coats of primer oil paint (exterior alkyd) and one top coat of the same in semi-gloss. There's nothing special about that. It's what I had on hand. If I were to buy paint it would be exterior latex acrylic semi-gloss.

2. Kids' bikes:

The cart wheels are 12" from kid's bikes, both fronts. Rear wheels are heavier, some with coaster brakes, all with gear cogs. I took the front and rear wheels off a solid tire bike and the front wheel off an inflatable tire bike, and switched tires to get two front solid. The wheels were taken apart to clean and grease the bearings, and to paint the rims inside and out with two coats of rust paint.

The bikes for the leeboards were different sizes but had identical steering components. I cut them with a hand held hacksaw. It went pretty fast. The ends were smoothed with a half round file. The down tube was cut off at the weld as close as possible and ground down with a stone wheel on the electric drill. Any bare metal was given a coat of rust primer. The headset was opened up, cleaned, and the bearings re-packed with bearing grease I use on the car. Some bike headsets have seals to keep water out. Not the cheap ones I got. I've used a plumbing O-ring to seal a headset but didn't have one the right size for these headsets. Maybe I'll get some later. Bike tubing is steel and will rust. I greased liberally. Unused parts were returned to re-Cycles. The long bolts used to secure the deck under the thwart are bicycle stem bolts.

3. Resins:

Polyester - Points of wear were given abrasion resistance with a coat or two of polyester resin, for example the inside of the box beams before they were assembled, the headset cutouts in the deck and, the bolt holes in plywood. In some cases wood endgrain was sealed with one coat of polyester, sometimes with paint. I wasn't consistent over the whole project. I just want to prevent the wood from soaking up water, swelling, and splitting. Polyester resin will keep in the 'fridge for years. I mix it in small quantities in the hollow bottom of an upturned soft drink can, up to two teaspoonsful at a time. One drop of hardener does for half a teaspoon of resin. It's mixed and spread with small pieces of plastic cut from a plastic jug.

Epoxy - Epoxy was used as adhesive, filler, or protection against abrasion. It was mixed in small quantities a drop or two at a time often with an equal volume of powdered talc from the bathroom to make it go further. It was mixed with a toothpick on a piece of plastic cut from a plastic jug. To soften it while mixing it was held up next to the light bulb over my workbench. I like the product in twin squeeze tubes from LePage for abut $5 because it's easy to squeeze out equal amounts of resin and hardener by eye. I've never used epoxy in larger quantities.

Polyurethane - Polyurethane was used as a wood and foam adhesive. PL Premium construction adhesive keeps in the freezer for years. I have to plan ahead and take it out about an hour before using it to warm up. I found a large tube of PL at a garage sale for $1. I tried making a dispenser out of downspout and a long bolt without success. I ended up cutting off the front end and scooping it out with a putty knife. To store it I cut the tube down with a utility knife, cut a circle of plastic to set over the exposed mastic to keep the air off it, found a preserving jar lid which fit over the tube, duct taped it on, wrapped it all in plastic, and put it in the freezer. That works well.

Resins: polyester - epoxy - Polyurethane

4. Shaping bulkhead:

People who build a canoe from a plan can take the bulkhead shape from the station moulds. I traced the shape from the hull on cardboard. It was done in halves. The halves were then put inside the hull and stapled together to get the whole shape. A perpendicular was dropped from a marker stick separately on the cardboard and on the plywood to align them for tracing the cardboard shape onto the plywood.

Cardboard forms

The End...

 

*****

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