DGentry
05-16-2012, 09:21 PM
Sort of a lark, and sort of an answer to a request . . . it's a skin-on-frame combination sit-on-top kayak (SOT) and stand-up-paddleboard (SUP). I'm just calling her my "boardyak."
I'll start by saying that I surf and snowboard, and "kind of" windsurf, but I've never been on a stand-up paddleboard. So I'm not making any big claims in that direction.
The original not-so-serious request was for a SOF sit-on-top kayak. I've paddled a fair number of SOTs, and I love the "get on and go" simplicity. But, most all those boats were roto-molded plastic, and pretty heavy - even the small ones. They all feature molded in drains, cupholders, seats and several recesses where your heels are supposed to go, depending on your leg length. Nice features, but difficult to mold into a SOF kayak frame. I thought instead of just having a flat deck platform, with a removable seat on top of it. Builders could add foot stretchers, cupholders, etc at their leisure, but only the platform is really necessary. And, I thought, since there's a going to be a flat platform anyway, why not be able to use the boat as a stand-up-paddleboard as well?
So that's what I came up with. I decided a Garvey bow would provide enough buoyancy, and a baidarka stern would act as an integral skeg, and that these shapes would both lend themselves to an easy build.
The boat is of non-traditional construction with marine plywood frames, rather than many steam bent ribs. There are no stressful bends in the stringers, at all, and I glued and screwed the whole frame together, which is much faster than lashing it. The fabric I used wrapped perfectly around the boat and I just stapled it to the central deck beam. Likewise, I stapled the skin to the fore and aft decks (1/4" ply), and sealed all the seams with glue and then paint - no sewing at all!
The deck is 1/4" fir plywood, screwed to the deck beams and gunwales, over top of the skin. It turned out to be bigger than necessary, which is good, since it weighs a lot, and I will be able to cut it down some.
I paddled it this evening, in a flat spot on the river down the road. As a kayak, she did everything a short kayak should do, and did it pretty well. The main difference being all that room on the deck! I could sit cross legged, lay down, straddle the boat or whatever. She was steady, turned very easily and floated (with me on it) in 5 inches of water. I used my folding camp seat about half the time, but didn't really need it.
As a stand-up-paddleboard, she's initially pretty tiddly - but only for a few inches of heel. As the chine submerged it was like putting on the brakes as far as heeling was concerned. I could put almost all my weight on one foot out to the side, and she was very steady. I got used to her quickly, and it turns out that the SUP thing is pretty fun - though I bet it would have been a lot more fun if my paddle hadn't been 18" too short.
So, I got bored after a while, and (sitting down again) paddled her out into the current and nonchalantly dropped into a 12" wave and surfed it until my clearly neglected stomach muscles started cramping in protest. In fact, she caught that wave a lot easier than my old whitewater boat could have, and that's pretty pleasing, as I hadn't planned on ever doing any surfing on her at all. Makes me think a trip to the beach might not be too out of the question . . . on a mellow day, of course.
11' x 30", about 27lbs (too much of that being the deck). 1/2" Marine fir frames, pine stringers, skinned with 8oz polyester. About 5 part time days to build, all told, and maybe $140 in materials.
Can't say I'm too enamoured of the "fat surfboard" look, but you can't see that from the deck!
Boardyak:
http://i174.photobucket.com/albums/w117/alias1719/Boardyak1.jpg
http://i174.photobucket.com/albums/w117/alias1719/Boardyak3.jpg
I'll start by saying that I surf and snowboard, and "kind of" windsurf, but I've never been on a stand-up paddleboard. So I'm not making any big claims in that direction.
The original not-so-serious request was for a SOF sit-on-top kayak. I've paddled a fair number of SOTs, and I love the "get on and go" simplicity. But, most all those boats were roto-molded plastic, and pretty heavy - even the small ones. They all feature molded in drains, cupholders, seats and several recesses where your heels are supposed to go, depending on your leg length. Nice features, but difficult to mold into a SOF kayak frame. I thought instead of just having a flat deck platform, with a removable seat on top of it. Builders could add foot stretchers, cupholders, etc at their leisure, but only the platform is really necessary. And, I thought, since there's a going to be a flat platform anyway, why not be able to use the boat as a stand-up-paddleboard as well?
So that's what I came up with. I decided a Garvey bow would provide enough buoyancy, and a baidarka stern would act as an integral skeg, and that these shapes would both lend themselves to an easy build.
The boat is of non-traditional construction with marine plywood frames, rather than many steam bent ribs. There are no stressful bends in the stringers, at all, and I glued and screwed the whole frame together, which is much faster than lashing it. The fabric I used wrapped perfectly around the boat and I just stapled it to the central deck beam. Likewise, I stapled the skin to the fore and aft decks (1/4" ply), and sealed all the seams with glue and then paint - no sewing at all!
The deck is 1/4" fir plywood, screwed to the deck beams and gunwales, over top of the skin. It turned out to be bigger than necessary, which is good, since it weighs a lot, and I will be able to cut it down some.
I paddled it this evening, in a flat spot on the river down the road. As a kayak, she did everything a short kayak should do, and did it pretty well. The main difference being all that room on the deck! I could sit cross legged, lay down, straddle the boat or whatever. She was steady, turned very easily and floated (with me on it) in 5 inches of water. I used my folding camp seat about half the time, but didn't really need it.
As a stand-up-paddleboard, she's initially pretty tiddly - but only for a few inches of heel. As the chine submerged it was like putting on the brakes as far as heeling was concerned. I could put almost all my weight on one foot out to the side, and she was very steady. I got used to her quickly, and it turns out that the SUP thing is pretty fun - though I bet it would have been a lot more fun if my paddle hadn't been 18" too short.
So, I got bored after a while, and (sitting down again) paddled her out into the current and nonchalantly dropped into a 12" wave and surfed it until my clearly neglected stomach muscles started cramping in protest. In fact, she caught that wave a lot easier than my old whitewater boat could have, and that's pretty pleasing, as I hadn't planned on ever doing any surfing on her at all. Makes me think a trip to the beach might not be too out of the question . . . on a mellow day, of course.
11' x 30", about 27lbs (too much of that being the deck). 1/2" Marine fir frames, pine stringers, skinned with 8oz polyester. About 5 part time days to build, all told, and maybe $140 in materials.
Can't say I'm too enamoured of the "fat surfboard" look, but you can't see that from the deck!
Boardyak:
http://i174.photobucket.com/albums/w117/alias1719/Boardyak1.jpg
http://i174.photobucket.com/albums/w117/alias1719/Boardyak3.jpg