boat side angle

How do I change the side angle from zero to about 12 degrees on a 12-14 ft Jon boat with a side height of 16-18 inches. I found a few articles online from old magazines with designs for Jon boats. I like how they look with the exception of one that has zero angle on the sides. I am a machinist, have my own shop, and am quite capable of building a boat.
Anyone have any suggestions? I am thinking of building a model first to see what my future boat will look like.

 

Dragon; are you referring to flare where the sides of the boat are wider at the top (gunnel) than at the bottom where the sides meet the bottom (chine)?

You could increase flare, if you must, but there will be a serious amount of work and expense to do so. Finally, why do you want to change the design of the boat? Do you presume that the boat will become more stable? That it will improve performance somehow? Please explain your motives.

 

It's a matter of preference. I have been in several Jon boats. Both with straight sides(same at the gunwale and chine) and with about 2-5 inches difference per side at the gunwale. Those with straight sides were what I would call a wetter ride than those with just 4 inches difference total across the gunwale.
I suppose I could just add a rub rail of about an inch on the outside of the gunwale to help keep water from coming over the sides.
I understand that building the boat in the one set of plans with straight sides, straight transom and a flat bow does make it much cheaper and faster to build.

 

Just find the plans with a design you like, there are thousands out there.

 

Old magazine Jon Boat plans with vertical sides PDF



Below some Jon Boat plans linked with slanted sides, all but the first from Duckworks, and it's about less than 1% of the total available out there I think...

— 1 — 2 — 3* — 4* — 5* — 6* — 7* — 8* — 9* — * = old Duckworks website, better try to find them on the new Duckworks website of link #2.

(some random pics from the above links)


Since you're a machinist with your own shop, all can be adapted for aluminum I think, if that's your preference, also plans can be found for aluminum.

Good luck !

 

Thank you!
I believe that the old magazine plans you refer to are the same ones that prompted me to start this thread. Lol!
I prefer plans that have ribs in them. It goes back to a boat that my father built after getting out of the army after ww2. He took three sets of plans and used design features from each to come up with a set of plans that he liked. A boat that could be used as a rowboat, very smooth to row, as a power boat with a 7.5 hp Scott Atwater motor, and as a sailboat. He also made the sail himself on an old treadle sewing machine. He did all this... disabled... Thanks again!! I greatly appreciate it!!

 

Slightly flared sides won't make for dryness on the plane, but will if going slowing or drifting with waves lapping against the sides, a rail along both sides an easy solution for the vertical sided boat.

 

From the designers listed at Duckworks there are 4 sets of Jon Boat plans by Jim Michalak at his power boats section.

Campjon​

12' Jon Jr. Plans — 20' Jon20 Plans — 16' Jonsboat Plans* → the same (for instant download) — 16' Campjon Plans (a slotted walkway ‘‘open cabin’’ Jon Boat)

* = the post #5 link #2

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I love the pictures of the 14' 7" Pacific Pelican (cheaper as instant download), a kinda Jon Boat style sailing scow, but it looks like a far more complicated build to me.

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For a quick and easy to build sail-row-outboard motor boat with built in floatation see the 12' OZ Goose (cheaper as instant download) by Michael Storer.

Good luck !

 

Dragon; a few other features might play into your particular requirements. Determine where you are going to use the boat, lake, river, seaway. How fast do you want to go and what size motor, if any, will you propose to use? Do you have any notions of rowing or sculling the boat for any distance? Do you have any notions about using a sail?

A planing boat has a bottom configuration that is straight from the finish point of the forward bottom curve all the way to the transom. A twelve or fourteen footer with a six HP motor will plane the boat perhaps 12 to14 MPH. ( as long as the total weight is kept modest) A larger motor will make the boat go faster of course. You could put a 15 or 20 HP motor on the boat for a lot more speed but at higher speeds the boat will pound your eye teeth out.

If you want to use a small motor like the 2 horse Honda on the Goose boat then the bottom configuration needs to be different from the planing configuration.

In this case the boat will not plane but it go along nicely and with some degree of comfort....just not very fast. The displacement bottom, as distinguished from the planing bottom, has some aft rocker. That is to say that the after part of the bottom curves upward to some point a little bit above the waterline. The Pelican boat that Angelique posted is of the aft rockered type. If you intend to row for 100 feet or so around the fishing spots then either bottom is OK. If you may need to row for any distance then the aft rocker is what you should contemplate. The whole idea is that at low speeds with limited power, the transom must not be even partially submerged lest it drag a bunch of water which causes unwanted drag.

One other detail that may influence your design selection........... If your boat is to have a predetermined beam, say for the purpose of fitting into the back of a pickup truck, then straight sides/flared sides become an item of interest. Suppose the maximum width of the boat is to be 45 inches. With straight vertical sides the boat will have significantly more initial stability than the one with flared sides. That is because the chine width of a 14 degree flare, with 16 inch side height, the chine beam becomes 8 inches narrower. The difference in initial stability is noticeable . Heeled righting moment is far more favorable with the wider chine.

I am an old time machinist who has made a lot of chips in the past. We are distant brethren by virtue of those chips.

 

Below the Oz Goose sailing and motoring, rowing can be done sitting on the athwartship seat that holds the daggerboard case, and ofcourse fitting removable oarlocks on the sides...

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The above would putter around much better with the 2 Hp if the skipper centered his weight in the boat, keeping the bow and stern transom both out of the water, and not letting the boat heel sideways. Sitting not higher than the forward seat that holds the daggerboard case, and sitting a bit forward of the aft transom, on a little boat chair facing forward with legs and feet forward would give a relaxed ride, mounting the outboard on the port (left) side of the stern and holding the left hand side control handle in the left hand, and maybe have an extended control handle mounted for this.

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a little folding boat chair: green - light gray - etc. = Dutch links, BTW means VAT.

P.S. - English US link for the little folding boat chair (unusual, but more expensive for this product)

 

Thanks for all the info and and help.
I feel I need to clarify what I am looking for.
I used to look at jonboats and cringe. I prefer boats with sides a bit higher than what I have seen in the past in jonboats. It goes back to growing up using my father's boat. I had a kayak I bought from someone I went to HS with... it was 21 feet long, approximately 30 inches wide (I'm being generous in that estimate) the cockpit was long enough for 3 people comfortably. It was also very top heavy. It would capsize if you sneezed. He built it out of one inch thick mahogany planks and he put a mast on it and had a sail not much bigger than a pillow case... once I made an outrigger for it, I could actually stand up in it and I made a triangular sail about 7ft x 5 ft, it moved along pretty well.... That was the last of my sailing.
The type of boat I am interested in will be used for fishing and just going out to relax in( a bad day fishing is still better than a good day at work)(fishing in the rain has advantages...just catch the fish as they swim thru the rain...).
As far as a motor goes... I have a 4hp Mercury outboard...but it was as burried in my yard by hurricane Irene for almost 3 months. I flushed it out the best I could. I also have a electric trolling motor. So I am not planning on getting it up on plane.
A Jon boat, to row around on a small lake, if I go out on any lake larger than 2-3 hundred acres,then my electric trolling motor and oars will be used.