Square stern on a Pirogue.

[Hydrophillic]

I have alittle bit of time coming up and with the now fiance~ back in her hometown picking her wedding out, I thought I would build another pirogue- God I love these things.

I have a question about square sterns. I can not figure out if I should taper it from the beam by some number say 10'' to the stern or should I just run the beam flare all the way to the stern? I hope this makes sense.
-John

 

[seedtick]

The more you taper toward the stern, the less turbulence as the boat sheds water and the easier it will be to paddle. But you're likely adding a square stern for capacity/stability or the ability to hang a motor off the back.

Every design parameter is a tradeoff or compromise in one quality for another desired quality.

I doubt you'll notice the paddling difference between a 10" and a 12" transom, but you'll likely be able to distinguish between a 12" and a 24". On the other hand a wider transom will let you run a larger motor.

Beekeeper has built a few skiffs, check out his latest post

 

[Kayak Jack]

It's also possible to have it a fine line of exit at the waterline, with a square stern above the waterline for a motor. Best of both worlds.

 

[Hydrophillic]

Thanks guys

I was thinking of keeping my beam at 32'' top and 24"bottom and making the stern 24" at top and 12" at bottom.The best I can describe it is a pirogue crossed with a glades skiff( the original kind). I guess I would call it a glade-rogue or a pi-glade.

I have thought of using a trolling motor on the back but more importantly I was looking for a little more stability. If it is stable enough , I thought I might be able to single oar scull it with an oarlock on the stern.That way I could fish as I propelled myself forward.

 

[woodman]

Here is what I did to an aluminum canoe to get the minimal flat back to attach a trolling motor...I cut a little off and spread the sides a bit....


Leave the V at the bottom and spread up top at the gunnels..

 

[mosportsmen]

Hey that's one of those Missouri made canoes....got to like that.

Osagian canoes has just came out with a new aluminum kayak. I think they just might have something there. The whole world is turning their noses away from canoes and looking at kayaks as the only boat to paddle.

http://www.osagian.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=Osagian&Category_Code=Kayaks

they make square stern too. I think your modification would probably make a better paddler though when you don't have the motor on.

Tom

 

[Kayak Jack]

Oh! Woe is me! Aluminum??!! Fit only to be used if fleeing an advancing enemy. :wink: Turrible stuff.

 

[Hydrophillic]

Pretty cool idea but notably heavy and sinkable. I did notice the similarity to pirogue. If they took the hood off I wonder how many pounds they would shave off but there goes your unsinkableness.

 

[woodman]

Oh! Woe is me! Aluminum??!! Fit only to be used if fleeing an advancing enemy. :wink: Turrible stuff.

Yea ..heavy..dosen't slide over rocks...need I say more...bullet proof.as long as you don't abuse it...did I say heavy...that is why I got into cedar strip construction..

 

[Kayak Jack]

Just before Chuck and I got e-acquainted, I started into kayaks. I'd been into canoes for years, then out, and then back in. I wanted a light boat, and assumed that aluminum would be it. Heaviest boat on the market! I was really surprised. Took me about three minutes to learn that lesson.

We paddled aluminum boats with Boy Scouts. They were purchased by a committee; that explains a lot.

 

[mosportsmen]

This aluminum kayak is not all that heavy compared to most of the plastic stuff on the market. 12 foot and the deluxe model with the hood is only 50 pounds. I know we can and do make boats longer and lighter but not too far out of what is popular on the market. Can't beat the tin for no maintenance tough. I think this could be a good boat for rentals and for people that want a boat in their back yard in the sun and weather all year and not worry about it. Lay a plastic boat out in the sun for 10 years and see what you get.

 

[oldsparkey]

I wanted a light boat, and assumed that aluminum would be it. Heaviest boat on the market! I was really surprised. Took me about three minutes to learn that lesson.

Not even thinking about the weight , the noise they make , how shinny they are or difficult to paddle ( slow in the water). My main complaint is in the Summer ( Especially in the 11 month summers down here ) are the seats in those boats. Leave it in the sun for 5 minutes and you will be standing when paddling it , you sure will not be sitting down. :wink:

 

[Kayak Jack]

<SNIP> I think this could be a good boat for rentals and for people that want a boat in their back yard in the sun and weather all year and not worry about it. Lay a plastic boat out in the sun for 10 years and see what you get.

Two good uses for an aluminum hull.

 

[beekeeper]

Thanks guys

I was thinking of keeping my beam at 32'' top and 24"bottom and making the stern 24" at top and 12" at bottom.The best I can describe it is a pirogue crossed with a glades skiff( the original kind). I guess I would call it a glade-rogue or a pi-glade.

I have thought of using a trolling motor on the back but more importantly I was looking for a little more stability. If it is stable enough , I thought I might be able to single oar scull it with an oarlock on the stern.That way I could fish as I propelled myself forward.

My perception, from my experances suggest flairing the sides, and widening the floor will add more stability than adding a (small) transom to a pirogue. A transom can add footprint, shorten the boat, make a place for a motor or oar lock, and increase drag (some). Flairing the sides will also add rocker. I don't know how you build, but the rocker can be set by the arc cut into the sides. My pirogue sides are flaired to 36" (about 30 deg.) and is noticeably more stable (secondary) than another boat I had with less flair. Widening the floor will increase drag (some). Every change is a trade off in another area. You just have to figure out which one you want.

beekeeper

 

[Hydrophillic]

Beheekeeeper,

I am with you on widening the bottom and increasing the flair. The first one I built was 22" at bottom and 29" at the top. She paddled fast but was too unstable. The second was 24" at the bottom and 32" at the top. She paddled alittle slower but was much more stable. I could stand up if not fighting a fish.

I guess am looking for just alittle more stability so I could stand often. I find sitting for long periods becomes very painful after a couple of hours regardless of the seat. A great thing about building your own boat is the ability to build until you satisfied and if you don't like it you out only $100 unlike the rotomolded plastic ones. Plus there is always someone willing to take it off your hands if the fleet has grown too large.

 

[Kayak Jack]

<SNIP> I find sitting for long periods becomes very painful after a couple of hours regardless of the seat.<SNIP>

This isn't a cure, but can help. Straighten out your legs, and roll your feet in a few complete circles, keeping them at the extreme outer part of the circle. Then, pump your feet forward and backwards. This stretches things out a bit and helps get blood circulating again.

 

[Hydrophillic]

I tried it all as far as movement etc to get the soreness out. I have a job where I am never sitting longer than about an hour. I on my feet the rest of time. The fiance says it is my boney butt etc. So building something stable enough to stand in has my motivation.