Building a flat bottomed canoe

Discussion in 'Wooden Boat Building and Restoration' started by troy2000, Jun 18, 2010.

  1. Silverbullet
    Joined: Jun 2013
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    Location: Somewhere in a swamp in Georgia

    Silverbullet Junior Member

    I posted this in a Pirogue blog only to find out it wasnt taking any more comments so Im gonna try to post it here.

    Experienced...
    I am a traditional wooden boatbuilder. I dont use any modern materials, especially not fiberglass.
    Once said, "If God had intended us to build boats our of fiberglass, he would have made fiberglass trees!"
    Ok. most plans Ive seen for the wooden Pirogues do not allow for the sides to be high enough to hardly keep out the water if the weight in the boat is over about 195 pounds. So if you are 175 pounds and you are building a Pirogue and you gain a few pounds you boat will take on water.
    You can put the bow into a wake and maybe not sink but highly unlikely.
    Put the seat in the center of the boat! Forget multiple passengers.
    Using a thin plywood, you will find that the boat full of water WILL SINK.
    You can install a cooler, sealed up, under the seat to help keep from losing your boat.
    Cajun folk are born standing up in Pirogues. YOU are most likely not a Cajun. My Pirogue has dumped me twice sitting down!!
    No, I didnt use pressure treated lumber, just two really heavy coats of Rustoleum gloss yellow on mine with a large decal of a crawfish, red, on each side.
    Mine is sixteen feet. I would recommend truncating one end, for a lot of reasons but primarily for a small outboard (I have a number of antique outboards less than 2 hp) or for an electric trolling motor.
    For all the conveniences and inconveniences they are a lot of fun and at kayak type meets, a real conversation piece.
    Ok what did we miss here?
     
  2. hoytedow
    Joined: Sep 2009
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    hoytedow Wood Butcher

    It sounds like a cool boat. You should start your own thread on this forum about it and post some pictures.
     
  3. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    "Using a thin plywood, you will find that the boat full of water WILL SINK." - sounds like nonsense. If they are referring to the effect of weight of the motor, even a thick plywood hull might get dragged under. Certainly sufficient extra buoyancy apart from the bare hull is essential for ALL small craft

    "wooden Pirogues do not allow for the sides to be high enough to hardly keep out the water if the weight in the boat is over about 195 pounds." doesn't apply if you are using plywood. - Pirogues were traditionally from one tree trunk, but with plywood, that limitation is gone.
     
    Last edited: Sep 29, 2016
  4. hoytedow
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    hoytedow Wood Butcher

    Troy, have you started any new boat projects?
     
  5. troy2000
    Joined: Nov 2009
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    troy2000 Senior Member

    Would you settle for an 'old boat' project, Hoyt?

    I picked up an old 12' aluminum fishing boat a couple of months ago, complete with trailer, for $500.00. I'm using it to fish the Colorado River (or trying to; the fish mostly laugh at me).

    It came with a 7.5 hp Eska (Gamefisher/Ted Williams) outboard, but I wasn't thrilled with it because it had no reverse and vibrated. Replaced it with a thirty-year old 9.9 hp Mariner International, that supposedly kicked around in a locker for years as a backup motor for a cabin cruiser on Lake Klamath. The seller's story might even be true: it runs like a new one and usually starts on the first pull, even when it's cold.

    The boat also came with a good-sized live well. I reinstalled that up in the bow, so I can use it as water ballast to level out the boat when I'm running solo. It's supplied by a transom-mounted pump, so after I launch the boat I flip the pump switch long enough to fill the live well - and away I go....

    I added a home-made jack plate yesterday to raise the motor, because the cavitation plate was three inches below the bottom of the hull; I'm planning to take the boat out later today to see if it makes a difference in how it gets on plane. It'll definitely make a difference in skinny water, which is easy to wander into on the river.

    I still need to rearrange the rollers on the trailer; they don't really support the boat properly.

    On the project that counts, I'm planning to order lumber and epoxy about the middle of this month so I can start assembling the frames for Cindy Lou. About damn time....
     
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  6. troy2000
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    troy2000 Senior Member

    As long as the boat is securely fastened down, it doesn't get beat to death; it just moves with the trailer. It isn't like there are any delicate instruments or parts... it's only a few pieces of wood glued and screwed together.

    Why not a little trailer w little wheels? Because this is the one I had, and I was having fun building it. :) It works just fine... I've used it to drop the Blue Canoe in the Palo Verde Lagoon, Oxbow Lake, Pretty Water and other back waters, and it's done fine on the rough roads.

    Something to keep in mind: the air pressure in tires should be proportional to the load. I found that out when I put my stripped-down Jeep on the road, and my teeth were getting rattled by tires aired up to 'recommended' pressures. Fortunately, my company put on a 4-wheel seminar for employees doing pipeline patrol across the desert. The instructor told us to mark a band of chalk across our tires, and drive around the block. If the middle of the chalk was scrubbed out, we needed to air down until the chalk wore evenly clear across the tire. It works for trailers too; I only have about 15-18 pounds in those 'big heavy wheels.'
     
  7. troy2000
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    troy2000 Senior Member

    That's such a reasonable-looking setup for a trailer that I wonder why we don't see it more often, Paul.
     
  8. PAR
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    PAR Yacht Designer/Builder

    I've seen this setup on several early and mid 60's trailers, but nothing on modern ones, likely because they've all but standardized frames and suspension parts. I just wish they made larger capacity torsion spring hub assemblies. These can really lower the boat on the trailer, if the frame is well designed. Some off road equipment trailers are using airbag/trailering arm setups, which look promising, if expensive.
     
  9. hoytedow
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    hoytedow Wood Butcher

    Glad to hear from you, Troy. Please keep us informed.
     
  10. Easy Rider
    Joined: Oct 2009
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    Location: NW Washington State USA

    Easy Rider Senior Member

    Troy,
    I am now faced with a similar situation. A friend gave me a small utility trailer. Was going to haul kayaks and canoes on it but bought a heavy 12' rowboat and want to trailer it. Haven't cut the springs down yet so need to reconsider that. The spring broke when I did that before but I ran the rig on a very long and rough gravel road in the wilderness in Canada. Also I'm going to need to be looking for a welder too.

    Low pressure tires would compensate some for too much unsprung weight but I lean a bit the other way. Too many people think max tire inflation is the recommended tire inflation. May be tough to find the recomended inflation for a given weight. Thanks for the chalk line method. Lots of trailer tires are bias ply. Would the chaulk line work on either bias or radial? I wouldn't think so.

    Glad you're back posting.
     
  11. troy2000
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    troy2000 Senior Member

    I see no reason why the chalk method wouldn't work on any kind of tire. They all bulge a little in the middle when they're over-inflated for the load they're carrying, and wear the edges if they're under-inflated. Although I would imagine that below a certain weight it doesn't really work well, depending on how stiff the tires are, so you just put enough air for them to hold their shape.

    When I used the chalk on my old CJ5 Jeep (with 31/10.50-15 tires), I wound up airing down from 40 lbs. to 25 lbs. It made a noticeable difference, both in the ride and in how the tires grip the ground. If I'm running in sandy terrain, I drop them down about another 10 lbs...
     
  12. PAR
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    PAR Yacht Designer/Builder

    The only time you should use the max inflation pressure rating on the side of the tire, is when you're looking to get the best possible fuel milage from it. It's simply decreased road friction, when the tire is full up and hard.

    Yep the chalk trick is an old one and works on both bias and radial tires. Big rig drivers have used this trick for decades, because getting a good balance on dual wheels is crucial to tire life. If one of the duels is very much different than it's neighbor, you'll cup the crap out of both in very short order.
     
  13. Easy Rider
    Joined: Oct 2009
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    Easy Rider Senior Member

    Troy,
    I'm not sure but it seems to me that the tread gets arched on radial tires .. as in concave to the road. So an overinflated tire would not even touch the road in the middle. Hence the chaulk line test.
    A biased ply would be the opposite. Arched but convex. On a radial tire the edges would get worn highly inflated whereas on a bias tire only the center may touch.

    But both would benefit from ideally inflated tire relative to the load.

    I now have a great idea on how to lengthen my trailer w two wood frame additions.
     
  14. troy2000
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    troy2000 Senior Member

    I have radial tires on my Jeep, and I had radial tires on my company work truck when I was doing patrols. Both vehicles scrubbed the center of the chalk marks, until I aired down. If you over-inflate any tire, radial or bias, it'll wear in the middle. Under-inflate it, and it'll wear on the edges.

    By the way: when I extended the trailer frame for the Blue Rose, I wound up having to shift the springs and axle back the length of the springs because the trailer kept bottoming out in the rear; it had too much overhang. Something to keep in mind...
     

  15. troy2000
    Joined: Nov 2009
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    troy2000 Senior Member

    A couple of updates:

    1. My son Dwaine and Dani, the young lady shown in post #190 on page 14, are getting married tomorrow (Thursday, April 13th). It'll be one of the few times (and maybe the last time) the world catches me in a coat and tie...

    2. Back when Dwaine and I were building the canoe, a couple of posters were skeptical of the Gorilla Glue I used to splice the pine sides and plywood bottom to length. But the boat has been kept outside in the weather continuously for 6 1/2 years years now, and the joints are as solid as the day we made them.

    I think the important thing to keep in mind is that GG isn't as forgiving as epoxy, and doesn't do well as a gap filler; it needs tight joints. When gluing a joint you wet one side with water, spread only a thin layer of glue on the other side, and clamp it well. Unlike epoxy, you should have minimal squeeze-out.

    I wouldn't try to substitute Gorilla Glue for epoxy on a major project, but it has its uses.
     
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