Questions About Making a 12ft Wood Skiff

Discussion in 'Boat Yard Basics' started by paint it black, Mar 29, 2009.

  1. paint it black

    paint it black Paddling away...

    I have been looking for a small skiff but I can't seem to find something to fit the idea I have in my mind. I would like something light enough to be able to scoot with my 5hp merc. My jon boat goes 14mph with the 5hp and I know I can get more out of it, but that's fast enough for what I'm looking for. I want a small little skiff to get real skinny. I have my bigger skiff with the 40hp for the bigger stuff but I would really love a small canoe-like skiff. Something that looks sort of like a miniature flats stalker 18, or gladesmen like skiff. Something that I can put a small poling platform, and push pole. suggestions on materials and whatnot. I have read where people use door skins for the outside. I will use the stitch and glue method. I would guess that I would use biaxial tape on all the joints, then cover the whole thing in 1708 biaxial cloth. Any ideas, and advice would be great. I searched for plans on but there's nothing like what I have in mind.


    I'm thinking maybe something like this.
  2. Brett

    Brett > PRO STAFF <

    That's an easy build Eric. Try a cardboard model first.
    That will give you an idea how the plywood will bend,
    and what the panels need to be, in order to end up with
    the shape you want. Cardboard and tape let you build fast,
    and modify fast. Once you have the total shape and layout
    you want, then you're just going to build if full size, you'll
    already understand the sequence you need to build in.
    What I see is a uncomplicated lumberyard skiff, that can be
    built from any exterior grade, void free plywood. You've seen
    my build, and B.Lee has his ongoing, the Sawdust Skiff. Both
    show, start to finish, the process you'll be going through.
    Build it, and I expect lots of pics of the build to be posted.
    That way I can make wisea$$ remarks at your expense.


    Or you can save the time and expense and buy a Gheenoe,
    because after looking at your drawing, and comparing it
    to the 13, they look the same.


  3. cojo_69

    cojo_69 08 Gheenoe Classic

    Hey Eric, get an older 13 highsider and you can do this to it. Looks like something you want.
  4. paint it black

    paint it black Paddling away...


    I haven't been able to find one. I have been looking. I would b e looking for one that needs work, so I expect to not pay much for it. Most of the ones on craigslist are all 800, 700, etc.
  5. paint it black

    paint it black Paddling away...


    Just off the top of my head, I'd say the hull would be about 12 feet to the motor mount, and then the sponsons would be about a foot making it 13 feet overall.
    I think it would plane easier than a 13 gheenoe. Which wasn't very easy to plane with my 5hp merc. A buddy of mine used to have one and we fished out of it a lot. It's not exactly what I'm looking for. Don't get me wrong, it's a good starting point, but it's not what I have in mind.
  6. Brett

    Brett > PRO STAFF <

    If you build it...I will watch!

    and make useless suggestions after the fact... ;)

    Build a scale model first, take pics and post them.
    Let's see the boat that exists only in your imagination.
  7. paint it black

    paint it black Paddling away...

    I just drew up a half ass drawing on photoshop. something like this, but with the front bottom rounded off.

    I'm no engineer, so I have no clue if these desired dimensions would even work. lol
  8. Brett

    Brett > PRO STAFF <

    You've worked in sheet metal,
    you know that what gets drawn on paper
    has to be solved differently in sheet metal.
    Build them models, post them pics.
    About the sponsons, I'm not sure your transom is wide enough
    to allow the engine to be mounted and then steered safely
    due to lack of clearance...

    See, I'm making comments already!

  9. paint it black

    paint it black Paddling away...

    I'll figure out exact dimensions once I tweak with some models. I would hope to be able to do some sponsons. I would like the hull to be 4ft wide. I figure if the sponsons are a foot wide, the motor would have about 2 feet to turn without any interference, but I'll have to measure it out to be sure.

  10. B.Lee

    B.Lee Well-Known Member

    This is great, more potential builders getting the bug. Once the wheels start turning in your head, it's hard to stop!

    I considered a sponson design on my skiff, but nixed the idea early on. In your case, you would benefit more from the added buoyancy of that portion of the hull, given a full transom. Your 5hp doesn't weigh enough to warrant the added sponson buoyancy. That sounds a little contradictory, but should make sense if you think of the sponson as an additional part, not an integral part of the hull.

    What made you start with a 13' hull design?
  11. marshman

    marshman just try to follow me....i dare ya...

    sponsons on a 4 foot wide boat with only a 5 hp?? unless youre just going for a "look", id scratch the extra work... a 13 foot boat with 1 or 2 foot long sponsons is only a 12 or 11 foot boat....if your engine is a 360 degree steer, you need prob 2 feet of transom width for, 1 or 2 foot by 1 foot sponsons wouldnt be that functional, for the amount of extra work involved....

    not trying to discourage, just trying to throw some thought into the mix...

    sponsons will add several more feet of "edges" and "surfaces" to finish....(glassing and sanding)

    :cool: :cool: :cool:
  12. B.Lee

    B.Lee Well-Known Member

    A lot more surface and material for the small gain in displacement they would give.

    Doing the math...

    12" wide
    12" long
    3" draft (since that's the only buoyancy benefit you'd gain, no matter how tall they were)

    432 cubic inches or 0.25 cubic feet

    two sponsons doubles that to .5 cubic feet

    that equals an added 31 lbs of water displaced, or buoyancy added

    on a 4' wide hull with the same 3" draft, you could get the same benefit by extending the hull 3"

    432 cubic inches / 48" beam = 9 sq inches / 3" draft = 3" extra length

    the placement of the weight of your motor is negligible in this case.

    I like math :)
  13. paint it black

    paint it black Paddling away...

    I have a 12 foot jon boat and like the functionality of it. I have my slightly larger skiff with a 40hp. I've always wanted to build something, and I thought that something like that would be cool. I would think to maybe sell my jon boat and 5 hp and buy a 10hp or something for this if it ever comes to be a reality. I've spoken to a few friends about helping me and they're up for it. Although one was talking about the sponsons being irrelevant, so I was thinking about it. Like I said I'm no engineer. I've always heard that they help the boat float skinnier, and assist in planing easier. The fairing of the hull shouldn't be a problem. I am a custom auto painter, with plenty of friends that do body work. I also have plenty of body work tools like hand file, line sander, Dura Block kit, detailing d/a, etc.  I would like the rounded chine, but I don't know about the extra work involved for the rounded chine. I want something decked out so I can fish out of. I have thought about decking out a Gheenoe but I can't find one for a good price. And I'm not about to spend $500-$900 on a Gheenoe to tear apart. If only we would come across them for really cheap or free like before.  :mad:

    I was originally looking for a Gheenoe before I bought my jon boat, and that's when I bought the jon boat off forum member "snooknreds2" I want something I can hook up nicely.