STITCHLESS stitch-and-glue..............?

In my mind there is little doubt that the stitching part of stitch-and-glue is a somewhat tedious process.   Yes, it allows quite complex shapes to be developed, yes, it is not all that difficult, etc, but….   Pondering this, I cannot help wondering if there is an alternative for a built-from-sheet-ply design.  Let me float this concept:   

  • forms are cut to the external cross-sections of the hull at regular stations (say every 12”);
  • forms are mounted on a strongback to give the outside of the hull shape (does this make it a male or a female mould – I never can tell the difference!);
  • ply hull panels are cut to pretty accurate shape (same as with normal S&G);
  • the panels are temporarily fixed (screwed, stapled?) inside the forms and adjusted to a close fit along all chines;
  • no stitching is done along the whole length of the bottom and side panels*. 
  • filleting is done inside the hull right along all chines;
  • fixed bulkheads are added;
  • internal taping over fillets, and external glassing, then proceeds as normal;
  • * I accept that some stitching may be necessary at the vertical bow and stern joints.
  Given the additional work involved in cutting and mounting forms, and making the strongback, I doubt that much time - if any - would be saved overall.   But, any extra work may not deter many builders – after all, something like this strongback/ forms approach is used with strip-plank designs to a greater or lesser extent.   One minor benefit  (if the concept works) is that multiple craft could be made from the one strongback/ forms set-up.     There are not that many theoretical advantages (apart from the one above), but perhaps there might be better accuracy and initial fairness in a hull so made.  I now await howls of derision from the usual suspects!   I’d be very, VERY surprised if someone doesn’t advise that John Q Citizen has been making kayaks in this way for years, but…  Wordsmith  

8 replies:

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RE: STITCHLESS stitch-and-glue..............?

Congratulations! You've just independently invented the basket mold method of construction. In the amateur world it's mainly used for larger boats that for some reason aren't suitable for a strongback or jig. Commercial builders use them for limited production runs.




RE: STITCHLESS stitch-and-glue..............?

I am a novice, having built only one Wood Duck, but I do sympathize with Wordsmith's  annoyance with copper wire stitches.  In the course of making every mistake the manual warns against,  I invented a new and unusual one: trying to soften the epoxy to extract a wire stitch by heating the cut-off end with a candle.  The resulting scorch marks are why my Wood Duck hull is painted.  Only the same deity that  watches over drunkards and small children kept the whole thing from erupting in an epoxy-fueled conflagration.   


Still the flaw in the proposed basket-mold system would seem to be this: "the panels are temporarily fixed (screwed, stapled?). . . "   A temporary fix is of course what the stitches are for.  Fixing the plywood panels to the forms on the strongback rather than to each other, may well leave gaps.  At least that seems likely when you are talking about the radical, to-the-point-of-breaking bends that happen in a Wood Duck. 

RE: STITCHLESS stitch-and-glue..............?

Well I guess I just don't get that. Stitching always seemed very fast and somewhat enjoyable to me. Certainly fast compared to cutting forms building and aligning a strongback? And enjoyable in that it is the point at which a pile of funny looking, wobbly boards, magically transforms into the shape of a kayak. But here is another idea if you just don't want to stitch:

Looks like too much trouble for my tastes. But YMMV.


Ogata (eric)

RE: STITCHLESS stitch-and-glue..............?

Folks, I agree with Ogata.  I'm as novice as you can get at 61 building my first boat, the Skerry and now working on the new Independence  RC sailboat.  The whole idea of stitch and glue is what attracted me to CLC in the first place.  When someone can take a novice (read that: boatbuilding dummy) and same novice builds boat, that's a miracle.  I LOVE stitch and glue!  Bob H

RE: STITCHLESS stitch-and-glue..............?

I do not think an external jig would save time unless you were building multiple boats, but it would eliminate all the holes, giving the finished product a more clean look.  I have seen boats built using tape and shrink wrap to hold the panels for the glue up instead of wires.  I think this would go well for a long thin boat, not for a truly tortured yak like the wood duck.

RE: STITCHLESS stitch-and-glue..............?

 To me the BIG benefit to S&G is ease of construction. Since I am NOT going to build the same boat a second time I want the decks clear so I can get on to the next hull. And I don't want a lot of leftovers from any one construction.

RE: STITCHLESS stitch-and-glue..............?

OK, I get it!   Consensus seems to be "yes, it could be done - indeed, is being done commercially with the 'basket' method - but why would you want to?".   I can accept all that - but I do like the using-sticky-tape approach, accepting that it would clearly only suit long skinny kayak-type hull shapes.


Thanks for inputs!   End of subject?



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