Simple Canoe

There have been a few canoe like objects put up on instructables but this one is really a pirogue- or flat bottom canoe. There is actually a lot of theory on boats like this one but the basic idea is you take two planks, stick them together at the ends with a frame or two in the middle, fill in the hole in the bottom with another plank and then add decks and thwarts and yokes and outriggers and sails and whatever else you feel like.

This boat is made from one sheet of 4mm marine ply for the sides, one sheet of 6mm marine ply, for the bottom and some sticks, fibreglass and epoxy to stop the thing from falling apart and to give yourself somewhere moderately comfortable to sit.

Most of the layout for this example comes from free sources on the web which I will include reference to where I deem I feel like it, but the main one is the lazy weekend canoe from the Toledo Community Boathouse
http://www.toledocommunityboathouse.com/plans.htm
This design is 6/7 of a Lazy weekend canoe, being 12 rather than 14 inches high and built using only 2 sheets of plywood instead of 3.

The canoe is a basic plan intended for two people and fishing gear on calm waters. Emergency floatation will be something like pool noodles tied under the seats and a beanbag cushion for the center. The back seat has a low back rest but the front is intended to be used in reverse when paddled single handed.

The woodworking skills required here are minimal and if you use epoxy, any mistakes are easily covered up, or filled.

In this layout it would traditionally be propelled by two people with one ended paddles paddling one side each. Two ended paddles can be used but to clear the sides easily you might need to make an extra long one. "Real" two ended paddlers will fit the length of the paddle to the person rather than the boat, which is fine till you are paddling something too wide for how you are tall. More on this in step 17 - water trials.

This is the perfect boat to use for your uke'n'paddle.

https://www.instructables.com/Ukenpaddle/

Buy Some Plywood

Buying plywood is one of the trickiest steps:

Marine plywood should be OK but sometimes isn't;
Exterior or structural plywood should be kind of OK but may have some bits that may require patching later (voids)and may not be as pretty and may have a good and a bad side;
Interior or non-structural plywood is probably not to be trusted.

Plywood also comes graded by the faces
A = A really excellent face
B = Nice but might be small imperfections
C = Could be better - small filled holes allowable
D = Don't go there girlfriend, or Decorative.

AA is usually sold as marine ply.
ACX or BCX (with the X standing for exterior) has frequently been used for making boats.

I used CD exterior pine plywood to make my wacky lassie and apart from having to do some patching of voids it has held up pretty well. I would not however recommend it.

Marine ply is usually stamped with a standard and most use the BS1008 British standard. The Australian standard is AS2272. If you do not live in Britain or other place that has mandated the British standards, the BS1008 stamp has no legal meaning. This does not stop many people (some of them unscrupulous) from using it anyway.

My plywood was 2440 by 1220 mm, which is so close to 8 foot by 4 foot given my accuracy we may as well call them 8 by 4 sheets.

CAD - Cardboard Aided Design

This step may be skipped by the skilled craftsman or the supremely overconfident fool, but it pays to get some cardboard and make a test scale model so you can see how it all goes together.

Take two (scale) 8 by 4 sheets (mine are one mm to the inch) cut one into 4 equal strips to make the sides.
Cut the other one on an even diagonal to make the bottom and make your test model. - read ahead for dimensions .

This little cardboard model is showing me how I will be happy with the bottom being 32 inches wide using one sheet of cardboard (I mean plywood) cut on the diagonal.

For a good idea of how your canoe (or any other scale model) is going to work in real life, use Lego or mega blox figures for 1mm to 1 inch scale and action figures for 1 inch =1foot scale. If you have pirate themed mega blox all the better.

Make Plywood Sides

Not much to this - cut the sheet of plywood for the sides in half, stack them on top of each other cut in half again.
Stack these on top of each other again and cut a 4 inch diagonal off the end of all 4 at once. This way if you make a mistake, such as cutting a 5 rather than 4 inch diagonal all 4 will have the same mistake and will still be even. Any length around 3 - 12 inches will give you a workable boat, the more you take off the more your boat will turn in (and as a consequence up) at the ends.
If your plywood has a good side and a bad side make sure you lay them so you can make a boat with all the good side facing either in side or outside. Feel free to change this up and have different ends.

Join the sides in the middle using your favoured plywood joining method. I used a Bolger/ Payson fibreglass joint where wet fibreglass is lain on the floor on top of a sheet of baking paper on top of a sheet of plastic on top of a piece of carpet. I have never had it happen to me but I am assuming that having plywood epoxied to your garage floor is not fun. The two pieces to be joined are placed carefully on top and more fiberglass is added to the top. More baking paper, plastic, a bit of a flat board and a heavy toolbox or similar weight to keep it flat. The experts recommend a 3 inch strip of fiberglass.
A scarf joint or a reinforced butt join with a piece of plywood are the other popular alternatives
see http://www.toledocommunityboathouse.com/plans/joints/index.htm for how to do them.

Make a Bottom Bit

After much fiddling about I cut a diagonal in the sheet of plywood starting from about six inches in from the corner along the short side to about six inches from the opposite corner, or thereabouts. Then join the two pieces in the middle using a suitable join - if making a butt join try and make it central and allow for clearance at the sides.

I did this after making the sides and sticking them to the temporary frame but a better time would have been roughly at the same time as making the sides so things will be glued up and ready to go at more or less the same time.
I forgot to take pictures so here is a cardboard model layout

Make a Central Frame (and Possibly Some End Ones)

Make a central frame.

There is a little bit of math here that kind of gives you your rocker, or the amount of curve in the bottom and top of the boat. All of this is far better explained in http://www.duckworksmagazine.com/01/articles/boatbuilding/2/part2.htm.

Here is my condensed explanation. Because we assume that the side of the boat is a cylindrical section, the outside corner points of the panel when viewed from front on is considered a right angle and we can square some hippos or something to work out that if the side panel is 12 inches and we want to make a boat with a 32 inch wide bottom and give ourselves 5 inches of rocker, Mr Pythagoras tells us that if we want the height from the bottom to be 5 and the other side is 16 (half of 32) then the hippo side is the square root of 5 squared plus 16 squared which is 16.763 inches and that 12 times 5 divided by 16.763 gives us the extra wide we need at the top to make our bottom go up 5 at the ends, which is a tad over three and a half inches. I am going to call it three and a half because I know this is that fancy book learning that gets you into trouble and makes your head hurt and wood also forms cones and parabolic splines as well as cylinders and never goes where you tell it anyway.

Why 5? Simple – because I dummied up something similar in the hulls program http://carlsondesign.com/software/add-ons/shareware/hull-designer and that is what it told me I kind of needed for something about this size so the stems would just kiss the water with 500 lb aboard evenly distributed. 5 inches is also conveniently about the width of a standard house brick/paver. The lazy weekend canoe, which has sides two inches higher than this one has a rocker of about 6 inches.

This frame is made from two bits of scrap wood attached to a piece of Styrofoam that I had laying around. Cardboard would have been just as good, if not better. In case you missed the maths and jumped to the end- it is 32 inches across the bottom and each end is three and a half inches longer than the bottom making 32 + 7 = 39 inches. Make sure the angles on both sides are the same.

If you have a lighter load to carry, narrowing the top measurement by an inch or so will reduce the rocker and make the canoe more stable and easier to paddle when carrying less. Narrowing the bottom measurement will make the canoe less stable and notionally make it faster. If narrowing the bottom measurement remember to narrow the top on as well or you could end up with a real curvy boat.

Join the Sides to the Frame(s) and Join Sides at Ends

Join the sides to the frame(s) and join sides at ends.

Depending on how you are making the boat the frames might be temporary like mine is or more permanent.

Stitching or duct taping the ends together in preparation for filleting and fiberglass is acceptable but I chose the stem method, measuring the angle with my bevel gauge to be carved with my plane. Those with a table saw to do such things can dial in about 40 degrees (or a couple of passes at 20 degrees). My stems stuck out a little way top and bottom initially and were glued in with titebond3 and stainless steel screws (an Aldi bulk buy).

Add the Gunwales (strips of Wood Along Top)

If you have more frames than I do and you use stiffer plywood you may not need to add the gunwales at this point and can go straight to tacking the bottom on but my sides were so floppy I had difficulty keeping it all together so the gunwales were added. To make the gunwales easier to attach I pre- bent them by making them wet and perching them between two supports and weighted them down for a few days.
For convenience I used my router to add six inch long finger/hook holds every six inches or so to the underside of the gunwale. This is a personal preference. Full length or no gaps are equally acceptable. In particular if you are going to store the boat upside down outside do not add the finger/hook holds as they will catch water and debris and will promote rot.

Here is the point where you take the ubiquitous - Here are all the clamps I own holding my gunwales on photo. Because I had plenty of screws holding it on I did not actually need to do this and half a dozen clamps to hold things generally in place while I did the screws up would have been sufficient but hey - it's traditional. I am not saying your dog will bite you and your wife will leave you if you forget to take a photo like this but I would not take any chances if I were you.

I used titebond3 glue here again, but I noticed it does not stick well to epoxy. The screws and the length of wood firmly glued down without the epoxy made this less of problem than it might have been.

Bung the Top on the Bottom.

A number of plans or ways of building boats and canoes have acurately laid out panels stitched together in accurate layout patterns or have solid frames arranged around something called a strongback. Because I had a degree of laziness and an accurate pair of pavers I used something I call a flat floor. Between the flat floor and the bottom panel I arranged spacers to maintain the curve of the floor panel to match the curve of the bottom edge of the side panels. You can use just about anything for this from the dried shrivelled hearts of your enemies to a roll of really soft toilet paper. I used two accurate 5 inch wide pavers for each end, some random scraps of 2 by 4 and 2 by 1, some empty crème caramel containers and a roll of really soft toilet paper. Always have a roll of really soft toilet paper in your workshop.
When you are happy with the evenness of the sides and the gracefulness of the curves of your boat tack glue the bottom in place - I used the epoxy I was going to use in the end, but I have heard of people using everything from 5 minute epoxy to hot glue to drywall screws to hold things in place. Having a center line on the floor and on the frame helps keep everything lined up.

At this point i have seen build blogs/articles where the shape was drawn on the base and then this was cut out and the rest of the build proceeded using standard stitch and glue techniques but I think I prefer my method.

Once everything was firmly stuck together I removed that temporary bottom brace and broke out some of that polystyrene, leaving the top brace in place for the moment.

The original lazy weekend canoe used external chine logs and a different join in the bottom of the canoe. If you are going to mix their method to attach the bottom with my cut, you may need to build the middle frame a smidge narrower.

Fillet and Fiberglass Tape

Now we have a nice open clean line we can add filler to our epoxy, make a smooth 1/2 inch radius fillet along the bottom edge and fibreglass over the top. I used epoxy but Bondo and polyester resin are probably acceptable for a boat of this ilk. I thickened the epoxy with plain wheat flour as per Hannu's boatyard http://koti.kapsi.fi/hvartial/ . For other tasks I used fine sawdust from my belt sander. Note the shape of the special fillet spreader which has the angle of the sides and the radius cut into it.

A time saving tip is to not wait for the fillet to set before adding the fibreglass strip over the top. You can be heaps messier laying down the fillet as laying down and smoothing the fibreglass strip will make evening out any underlayng unevenness easier. It also saves the whole sanding off the wax layer thing that you have to do if you are using poly rather than epoxy.

After I glassed it I noticed the left and right sides were not quite as even as I thought. Never mind this will probably make it tend to turn in one direction or another, making it easier to do a J stroke ;)

Flip Over and Trim Off the Excess.

Now we flip it over and trim off the excess. I tried using a flush cut saw attachment, on my multi-tool but that was too slow so I tried a manual flush cut saw which I could not get to go parallel for me. I then noticed the plywood was 6mm, so I resorted to my router to which I attached a 1/4 inch roundover bit (=6.4mm) which worked really really well - until the melting epoxy got into the guide bearing and it burned out, creating a small mess. A 10mm roundover bit was then resorted to and the edges were then cleaned up with a plane and sanded smooth.

A jig saw with the base tilted to about 30 degrees so it did not hit the side of the boat would also have worked nicely and perhaps not created as much sawdust, leaving more leftover plywood for making paddle blades and the like. As you can see there was not a lot of plywood left over.

Glass the Outside Edges

Due to the mishap with the router a bit more epoxy with filler was required but apart from those places the epoxy went on the sides swimmingly, which is more than I can say for the stems, which were decidedly messy.

A word of warning about epoxy. It is a lot easier to wipe off/in when it is runny than it is to sand any drips off when it has set.

Add a Keel Strip

Glue and clamp down a keel strip- put some screws through the bottom to make it clamp to the bottom of the canoe more evenly. Remembering to have a center line was a big bonus here.

Add Front and Rear Decks and Bracing

Now we re-use the offcuts from the sides to make the front and rear decks. We first use the offcuts to mark the largest area we can cover then we start fitting angles. This is a lot easier than it might look to the layman. Firstly the angle of the top is drawn in by having the piece of wood upside down. we then flip it over and draw the angle of the side up, using a simple strait edge. Align your saw to both angles and presto - a neatly fitted piece of wood. Because we used epoxy a bit of leeway is acceptable and the piece of masking tape was all the clamping pressure we needed to hold it in place. Screws were added as a secondary joining method later.

At the bow (front end) I am putting a bit more reinforcing to take a tow bar so I can tow it behind a bike, and as a strap down point when carrying it upside down on my roof racks..

Add Seats

The side seat supports are ten inches apart and the front of the aft seat starts 36 inches back from the center and the rear of the front seat starts 28 inches from the center. I took these measurements and layout from the lazy weekend canoe. There are formulas for working out the spacing of canoe seats if you have the weight of your intended occupants and you have the inclination, feel free to Google them.

The side supports are bevelled so that the seat horizontals will be aligned with them. I glued the sides with temporary braces clamped to them to keep them aligned. I made these temporary braces long enough so I could trim them to make the permanent braces. When putting the permanent braces in ensure you either make them butt securely against the side or (unlike me) leave just enough room to get a paint brush into the gap to seal the end grain. Pre-sealing with epoxy would be another good option.

The height of the notional front of the seat was set as 8 inches from the floor and the height of the back was set using a spirit level while the canoe was kept level with my precision 5 inch wide pavers.

Note the pencil line drawn in to show vertical and that the parts are all numbered as I go to avoid mixing them up as they are all cut to fit.

You might notice I replaced the remainder of that temporary center frame with a cross piece (or yoke, or thwart). This adds structural integrity and makes a useful point to carry the canoe upside down on your shoulders. Some people take a bit of time to shape the yoke to fit their shoulders and neck if they plan on carrying the canoe for long distances, or maybe just for show. If I had been thinking ahead my temporary frame would have had a permanent element.

Add Seat Slats

The seat slats were added from the center out, spacing the slats with a small jig knocked up from scraps for the purpose.

Alternatively you could go with any other seating arrangement you chose including; plywood ; weaving a seat into the frame; an old lawn chair, etc.

I think this canoe would work reasonably as a single person row boat with a central seat and six and a half to seven feet oars. Notionally there is a bit more rocker than required but this can come in useful when rowing because of the shifting center of gravity.

Sand and Paint Before Putting in the Water

Trim off excess wood.
Sand and paint before putting in water. You also need to ensure your epoxy or polyester resin does not have any Amine blush or wax left on the surface because paint does not stick to that. Some epoxies like the 2:1 Botecote epoxy I used is not prone to those problems. Polyester resin always has a wax residue on the surface, which allows it to cure properly.

The paint and colours I am using here are the product of careful selection from the back of my cupboard of leftover paints and from the miss-tint and return section of my local hardware store. All are just ordinary exterior house paints.

The undercoating was applied in two coats, one watered down and one full strength.
The inside is Antique White (USA) - leftover from my kitchen doors.
The outside is Canadian Pine.
The trim (gunwales and seats) is from a "computer prediction" which apparently didn't because it had been returned.

Remember to wait after painting for slightly longer than the "touch dry" time before sticking it in the water as paint takes a good while longer to cure fully before being at its full hardness and may re-emulsify (i.e. soften, or wash off) if it is put in the water for too long. A quick dip to christen it should not be too much of a problem but painting the day before a week long canoeing trip is probably going to end in tears.

Total weight after painting was about 29 kilograms or about 64 pounds.

Using the Canoe

Now put your life jacket, PFD or whatever else you call it on, put your canoe in the water and paddle it.

My son is responsible for the name "Neef the Canoe".

The theoretical way to paddle a two seater canoe is with one person in each seat using single bladed paddles but I found using my double paddles quite easy. The shorter store bought 7 foot long double paddle required more leaning over to get it in the water and clear the sides but the home made seven and a half foot paddle with the smaller blades cleared the sides easily and made the boat scoot along easily. If you read some paddle fitting guides they fit the paddle to the person but you have to fit the boat as well.

The official way to paddle a canoe like this with one person in it is to sit in the front seat facing backwards. Being perverse I tried paddling from the back seat facing forward and found the comfort of the back rest seemed to compensate for the slight extra nose out of wateredness.

Some of that nose out of wateredness is a product of the even rocker in the bottom of the canoe, as the floor of the canoe traces a smooth roughly circular arc. More sophisticated designs like Mik Storer's Quick Canoe tend to have a flat spot in the middle, curving up more abruptly at the end. For a comparison see:
http://toledocommunityboathouse.com/plans/lazyweekender/100918_comp/index.htm

A few days after these pictures were taken I took it out by myself while there was a bit of wind about and found to get any sort of control I had to sit in the middle on a cushion and use the double paddle, though that double paddle thing is probably more a product of my lack of single paddle practice. The wind was gusty rather than than continuously strong and individual gusts woud catch one end of the canoe or other swinging it about, or weathervaning it a bit. A skeg and foregripe* like on Mik Storer's Quick Canoe would improve the tracking, but at the cost of affecting manoeverability and in water clearance. No boat is perfect - even the best of them are just an accumulation of compromises till something convenient pops out.

One of these days I will bring an extra camera operator so we can see how good the trim is with me in the back and my son in the front and vice versa and with extra gear etc.

* A skeg is a vertical fin at the back of a boat designed to help keep the boat going in a strait line. A foregripe is more or less the same thing at the front.

Simple Canoe

Simple Canoe

Buy Some Plywood

CAD - Cardboard Aided Design

Make Plywood Sides

Make a Bottom Bit

Make a Central Frame (and Possibly Some End Ones)

Join the Sides to the Frame(s) and Join Sides at Ends

Add the Gunwales (strips of Wood Along Top)

Bung the Top on the Bottom.

Fillet and Fiberglass Tape

Flip Over and Trim Off the Excess.

Glass the Outside Edges

Add a Keel Strip

Add Front and Rear Decks and Bracing

Add Seats

Add Seat Slats

Sand and Paint Before Putting in the Water

Using the Canoe

Further Reading and Similar Things on the Webniverse