Stitch and tape construction for small boats is a renowned method for ease and speed of construction. There is nothing about what you are about to see that is terribly hard, nor is it terribly slow( for anyone other than me!). I have taken a number of deviations from the path of speed and ease, but I have for much of the time been enjoying the process as much as I will enjoy the completed boat.
For those unfamiliar with the technique, no framing or moulds are required, it's simply a matter of cutting out the panels, stitching them together with wire or cable ties, glassing the joints, and going boating!
In the time I've been building it, I've gained three new sons-in-law and a grandson to boot, so the journey has been quite a joy really.
Once it became clear that the prototype boat was going to end up somewhere round hull number 100 actually completed I didn't feel so obliged to build strictly in accordance with the plans, but were I have made a couple of small deviations I have noted them in the text.
Lofting is really a flash word that for this boat means "marking out the ply". To do that you'll need an accurate rule, a square, (although anything a bit square, such as the side of a cardboard carton will do the job admirably), and a pen.
Mark gridlines at 300 mm (1 ft) centres as shown on the drawings, and you've completed the first stage.
Once the gridlines are in place, it's a simple matter to measure the correct offsets to get the lines for each panel.
Tap a panel pin into each of the intersecting points, and using a flexible batten to join the points in a beautifully fair curve, mark the panels.
Weights will help hold the batten against the pins, and if you have a spring clamp or two they are indispensable for this job as well.
For the areas such as the bow and stern panels which have a very tight curve, a more flexible batten will be required. In thin ply, the spring clamps may pull the panel pins out if there is too much pressure, so an extra pair of hands will make things easier, particularly if you are going to take a photograph!
I have a selection of flexible battens, this one is a fine timber louvre scrounged from some broken blinds.
Once all the panels are marked, it's time to bite the bullet and start cutting. I know it sounds simple, but make sure you are cutting on the right side of the line and a few mm outside it.
This will enable you to come back with a plane or belt sander, and trim very accurately back to the line.
While a power jigsaw is nice, I have also used a standard carpenter's panel saw, and a Japanese pull saw for this task.
Here, the first three panels have been cut. From left to right, top, bilge and bottom.
There's no need to mark more than these three panels, as once cut they can be used as templates for the others. Some builders stack the panels and use a router bit to trim them all identically, but I rather masochistically I suppose, enjoy the cutting and planing process.
As with many other components, I am in no hurry and like the work.
I'm a really messy worker, so I like to tape up areas where glue mess is likely, saves a lot of cleaning up later. Here the blue outlines where the butt strap will go. The packaging tape is on the underside (outside) face. I like to do that to limit the spread of epoxy and also to keep the panels located during assembly.
I also chamfer the join to ensure a nice tight fit on the finished surface.
With all the pieces joined, the five pieces will shortly become a canoe, but first it's time to precoat the inside with epoxy.
If the interior is finished as we go it will save an incredible amount of work cleaning up later.
Before stitching the panels, the butt straps need to be bevelled to ensure that they are going to meet correctly when the panels are stitched, I'll explain later!
I use a marking gauge to ensure the holes are lined up nicely, then drill holes at 4" centres along the edges. I'm using a 1/16 bit and I'll use fine wire to stitch it all together.
Cable ties can also be used successfully, but don't give quite as neat a job to my eye.
I've also bevelled the panels for a tight fit, this is NOT recommended as it over complicates the job, and not all panels will be correctly shaped, so some slight adjustment may be necessary.
Sanding is something one gets used to when building a boat! Before assembling the panels it pays to get them sanded ready for a finish. It's a LOT easier sanding flat panels than sanding the interior of a finished boat.
The stitching begins. There's no need to tighten everything at this point, in fact it's better if it's a bit organic so that any adjustments can be made as we go along.
After what seems like a few minutes work, the bilge panels and bottom are connected. It always gets a bit exciting at this point, because the boat is halfway to its final shape.
And here it is, loose tied and floppy, but giving a fair idea of how it will look in not long at all.
Before tightening everything, it's a good idea to the get the temporary spreaders in place.
At this stage, we were prototyping the construction and the plans have subsequently included a suggestion that the centre spreader be included during the build process to keep the beam (width) to its correct dimension.
Here the tightening has begun, starting in the centre and gradually working towards the ends. I've pulled it all down and fiddled with alignment and will come back to give it a final tweak.
Almost done, the top/bilge panel join needs quite a lot of tension in the front 18" so I've halved the spacing of the ties.
The vee joints I created are fairly obvious at this point, but it's also easy to see that the panels are all properly aligned, the wire pulled tight and all is ready for gluing.
At this point again I'll remind myself that this would normally be a butt joint, with a small vee on the outside ready to fill. I've pretty much achieved my aim, but its a self-defeating quest.
As soon as one achieves a better joint, one becomes more critical of it, setting off more work to improve it and so on.
The wires can now be pressed down into the join so they'll be completely covered by the glue.
This shot shows the butt straps aligned. Had I built in the normal way, the butts would have resulted in a tidy mitre with just a little fill.
I intend using an epoxy glue mix in the fillet instead of glassing the inside, so I'm quite happy with this joint. Had I been glassing as is more customary, I would have used a series of epoxy "stitches" to hold the seam together, and removed the wires before glassing.
The easiest way to ensure a stitch and tape boat stays in it's correct shape is to fit the gunwhales temporarily before glassing. They can be screwed in place, but for reasons I can't recall, I chose to use clamps.
The concave in the foreward hull shape is quite apparent in this photograph.
Looking a bit like Frankenstein's monster with all the stitches hanging out, and the gunhwales glued on, there's nothing too loveable about her from this angle.
Ready to glue the inside, but I can't help but stand back and think about how great she's looking!
The temporary spreaders are now fixed in place, the temporary gunwhale secure, ties are tight, and every thing is ready for glassing.
Now is a good time to run some straight edges across the boat and check that everything is parallel and that there's no twist in the hull. Once the epoxy is on, it won't be possible to make further adjustments.
And then I walked outside to see a storm arriving at sunset, causing a really weird colour, partly helped by the camera light balance still being set for inside of course.
Until now, I've avoided making mention of the fact that my temporary gunwhales were cheap finger jointed pine. After day or two under this load I wandered into the shed to find one side of the boat had a definite flat spot in it!
Off it came, scarfed a proper joint in it and in another suspect spot, put it all back together again and lose a day!
Glad it wasn't the final piece.
I have decided (after consultation with Michael) to tape the outside only, and to use epoxy fillets inside.
The best way to get a great job is to mask the fillets, and here I use some masking tape to lay a line, and mask up to it. Using this method I can ensure that the fillets will have parallel sides.
Before the fillets cure, I remove the tape. Once they cure to a rubbery consistency I'll work them a bit with a detergent soaked finger to minimise sanding later.
Looking forward, or perhaps aft, there's a disturbing optical illusion which gives the impression that the boat is twisted, or at least not symmetrical.
The first of the fillets is part sanded which explains its lighter colour.
Neat! The fillets have cured and we've turned the boat and cut and sanded the wire back level with the surface. The boat looks great, like a kid who's just had her braces removed.
Now on to the bulkheads!