Stitch & glue without the stitch, any hints?

Discussion in 'Boat Design' started by Jethrow, Mar 19, 2022.

  1. Jethrow
    Joined: Jan 2011
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    Location: Sydney, Australia

    Jethrow Junior Member

    Hi all

    I have a small project gelling in the back of my brain. Previously I've done a few stitch & glue dinghies including tortured ply construction, however this will only be small (less than 2 sheets of 3mm all together) and I wanted to clear finish it. Therefore I want to do it stitch & glue without drilling all the little holes for the copper stitching.

    There's no compounding in the shape so I was considering small gussets of plywood hot glued to the panels to hold the angle while the epoxy fillet goes off, then remove the gusset & glue and do the rest of the filleting. Someone told me the hot glue gets messy but I think they'll all be inside the finished structure, so if it damages the surface it's not a huge issue.

    There will be maybe 3 * 2m long sections of between 50mm and 150mm on each side which is why it needs to be relatively easy to do.

    Another suggestion was dabs of meth-acrylic glue with spray on hardener but some of my seams will be from underneath so this sounded too messy.

    Any other brainwaves? As it's just a small project and a bit experimental I was trying to stay away from extensive jigs and such. Your thoughts are appreciated...
     
  2. AlanX
    Joined: Mar 2022
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    Location: Perth, Western Australia

    AlanX Senior Member

    How about hidden seams?
    Here is my pontoon before the lid goes on:
    Trial fit of the lid:

    While I used stitch and glue, for the main hull, I glued the lid on.
    You could do all this without wires.

    I built another pontoon by calculating the internal angles every 100 mm.
    I then cut lots of wooden triangles (as running cuts on a piece of timber) and screwed them in (not doing that again, too much work).
    I then just sealed the edges with thickened epoxy.
    Instead of screws you could use super-glue.

    Otherwise, just drop back to the traditional plywood on bevelled frames.
    The screws are hidden by external stringers.

    AlanX
     
  3. latestarter
    Joined: Jul 2010
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    Location: N.W. England

    latestarter Senior Member

    Tape is the answer.
    Your fellow Australian Michael Storer used it on his quick canoe Quick Canoe Plan - two weekends work for a handsome, light wooden canoe https://www.storerboatplans.com/boatplans/quick-canoe-two-weekends-work-and-a-handsome-light-small-boat/

    The first time I came across this was by Flo-Mo an example here Two sheet boats http://flo-mo.weebly.com/two-sheet-boats.html see Romax 16 second photo. He is an innovator in canoe design. He used to have a step by step guide but I am struggling to find it.

    Inspired by Flo-Mo I used tape when building my canoe, the only parts where I resorted to copper wire and cable ties was the highly twisted planks at the ends.

    The secret is to get a tape strong enough to grip that does not pull up the surface of the ply or leave a residue when removing it.
     
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  4. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell . . . . .

    Tape.
     
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  5. Milehog
    Joined: Aug 2006
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    Location: NW

    Milehog Clever Quip

    I recently discovered gaffers tape, it is strong and leaves no residue that I'm aware of.
     
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  6. cracked_ribs
    Joined: Nov 2018
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    Location: Republic of Vancouver Island

    cracked_ribs Senior Member

    I like surgical tubing for stuff like this. You bend stuff over a simple mold, and wrap the tubing around and tuck the ends under a few wraps.

    No adhesive to get absorbed; clamps any shape at all. Easy to vary the tension locally as you go. Generally available at big fishing suppliers.
     
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  7. upchurchmr
    Joined: Feb 2011
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    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Superglue.

    A leading kayak designer uses this to position strips for strip planking, before coating the strips in epoxy.
    The unfilled epoxy wicks into the very small joints.

    For plywood, you would just paint the joint with unfilled, then use filed epoxy to make the seam.

    You just put dots of superglue every few inches, not a continuous line.
     
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  8. Ike
    Joined: Apr 2006
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    Location: Washington

    Ike Senior Member

    I have built two stitch and glue boats. I did not use wire and drill a lot of holes. I used a few holes where necessary and opaque white plastic wire ties, and tape. It worked quite well. I had some issues with the tape leaving residue but a quick sanding fixed that. But if I were to do it again I'll try to find a tape that is strong enough but doesn't leave residue. I used the wire ties because if you can't get them out (I had a few like that) you just cut them off, sand them flush and glass over them. They don't show because they are the same color as the fiberglass.
     
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  9. The Wing Guy
    Joined: Mar 2022
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    Location: Atlanta

    The Wing Guy Junior Member

    I use hot glue often for this kind of thing. I use as little as possible, and usually as an adjunct to zip ties... I don't generally use wire. I have virtually never had any surface damage when removing the braces. I try to keep the glue superficial, in little dabs, rather that actually between close fitting parts, so the joint is week and easier to remove.

    I am in the midst of a project that requires hundreds of such dabs, and would like something faster, but have not found anything.

    If the fillet side of something is bright finished and the outside painted, then the stitches can be under the fillet, if the holes re near enough to the edge.

    Also, the stiches can be uniformly and and carefully spaced, and then they can look fine for many projects.

    I have not had much luck with superglue and wood, and don't want anything to flow into where the epoxy belong.
     
  10. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    I have built a few S &G type boats using neither wire nor tape. Build some outside frames and use wooden wedges to force the ply into place. Works nicely for simple dinghy shapes that do not have too many strakes.
     
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  11. kerosene
    Joined: Jul 2006
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    Location: finland

    kerosene Senior Member

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