A Jonboat build– original in style meant to be paddled
I have forever wanted to build my own wooden boat. I studied, read, searched the internet some 25 years on this subject and only recently was able to start a project. I remember that when i was 6 or 7, my maternal Grand-father was building such a boat– a Jon Boat– yet I remember nothing about it. He was a carpenter by trade, thus able to do so, and I assume that he was building in a local boat style of Eastern North Carolina.
There are many plans out there: I wanted a traditional paddle type Jon which had side flair and rocker at both ends, for paddling and use of a trolling motor. I wanted it to be able to slide into a pickup bed and not so heavy that this could not be accomplished by a single person.
See plan links at end of article..
I decided that I would build my initial boat from 1×12 common boards from the “Big Box stores”. The side boards shown here are probably spruce, but a more rot resistant wood would be better–say Cypress if available.. with slight changes and framing, the boat can be built with plywood sheets, if you include chine logs on the floor and rails at the Gunwales.
I selected two 1×12 x12 foot boards. They were actually 3/4 thick by 11 3/8 wide. My plans call for a 4 inch rise at each end on a 16 foot boat which (the rise) starts 48 inches from an end. Since my boards were narrower and the boat shorter, I caused a 3.5 inch rise at 36 inches from the end.. I marked and used something flexible to make a fair curve along the cut. The 11 3/8 wide boards, now rise to a width of 7.5 inches at each end– 36 inches from the end..
I cut it out>>>
I used the cutoff remnant to mark the exact shape to the other three edges. Then I lined up the two boards and sanded a bit along the edges..
The plans call for a form to be placed in the middle to shape the boat.. it is 35 inches at top by 29 inches at the bottom for 12 inch side boards– the difference in the side widths (mine are 11 3/8), I don’t think changed the angle so I thought nothing of it, as long as the form was flush at the bottom edges.. This is held in place with a binder and carefully tacked or screwed into place to hold and form the shape. Do not nail or screw all the way in, as it will be removed.
You can make the ends the same size, or one can be taller as a trolling motor transom– your choice.
I made the front to be flush. It measures 27 at top by 25 at bottom by 7.5 tall.. The plans call for 27x25x8 for the 12 inch sideboards.. I used Resorcinol glue (Cascophen) from “Aircraft Spruce Company”. you may use this or epoxy. I fitted the board and held it in place with a strap binder while I edge nailed with 2 inch Silicon Bronze Ring Shank nails. As you can see, above, I pulled in the opposite end to about 27 inches with another strap..
The Transom is 27x25x11 3/8– double thickness (of this 3/4 inch board)– glued and nailed with 1 1/4 bronze ring shanks. You are going to round the edges and probably cut sculling notches at the edges so plan for that in your nail pattern.. In the picture above, the cross board is tack nailed to hold the transom up into place while i glued and nailed with 2 inch ring shanks.
In the scheme of things, the top of this transom will be 11 3/8, plus the 3.5 of the side board rise, so the top of the transom will be about 14 3/4 from the bottom center of the boat floor.. which may work for a small short shaft motor.. and surely with an adjustable shaft trolling motor.. The ends come inward tight enough to your body to make paddling easy.
Note: with rocker at both ends, it is designed to paddle and is not a “planing” hull. I think a 30 to 40 something pound/thrust trolling motor would push this boat all over– if you must use an outboard, perhaps it would be the lightest 2.5 HP that you could get.. But remember, it is what it is, and that is why I am building it (for the same reasons others have built it). This is your light paddling boat that was designed and used for ages– it is like the “Pirogue” for everywhere else!!
Glued up and bound for drying..
On a board boat, the cross pieces must be level with the inside edge of the sides.. You will plane the sides until they are level in an upright manner so that a flat area is available for the bottom to fit against. You can use a straight 2×4 to lay across the boat at all point to use as a gauge that you are planing it level. In the photos below, you see that I have planed and sanded across the transom joint, so that it is level, and that it follows the curve of the side-wall. That Resorcinol dries in a red-purple color..
I continued by placing 1×2 oak cross pieces at 2 foot, 4 foot, 8 foot and 10 foot from the transom. The a 1×4 was placed flat at the center (6 foot) to be the glue and nail lap joint for the bottom plywood. The mold was removed and this board was placed. The other cross-members where placed perpendicular to the “floor”. I believe i used 1 1/4 ring shanks to nail — two nails from outside the boat into the ends of the cross members.. Please pre-drill the nail holes with a a small bit to avoid splitting the cross-members.
When she dried sufficiently, I flipped her over for a look….
(those 2×4’s are to widen my table– not part of the boat)
Rear transom detail– you could cut a sculling notch if wanted– like centered or at each end.. just plan your nail pattern when laminating the transom..
Wood putty time and putting that “pleasing curve” on the transom corners.
Flip over and check for “squareness”.
Putting on the 3/8 Plywood bottom with Resorcinol and Bronze Anchor nails.
The bottom seams and corner seams will be covered in 3 inch fiberglass tape and epoxy.
As stated the rear transom can be made flush, or for a motor (as shown), The transom is calibrated for a 15 inch foot small motor.
Now to complete the seam taping and determine where bracing and seats will be.
I will get that, so stay tuned for more– check back often.. I will add supply links as well..
Good Day— Mike
NOTE::: I’m not done as of August 2021– but I mean well– keep looking for updates