Bayraider 17 kit build - first finger joint

[Anthony Huggett]

In the BR 17 Swallow boats have dispensed with traditional scarf joints for the long plywood planks, in favour of interlocking finger joints.
Here's my first stab at one, and a few thoughts on how to do the next one better.

The CNC cuts all the way through (thank you Matt!) for the fingers themselves, saving hours of intricate work with a jigsaw. That said, the edges are quite rough: I found it better to turn it over between cutting and the first sanding to remove the chewed up wood around the cut.

The sailing knife in the first shot is for scale; it played no part in the job. The fingers below the knife have been sanded.

[Anthony Huggett]

The reverse side showing more chewed wood.

[Anthony Huggett]

And here's the assembled finger joint. It took several hours of sanding to get to here.

Notes to self for next time:

Don't skimp on sanding the fingers and think you'll get away with a very tight fit - squeezing the fingers into place when they are slippery with epoxy isn't fun.

For the glueing I'm trying to work on top of a new PCV rubble sack to which I hope epoxy will not stick. I draped it over the bars on the cutting box but it needs to be padded out with some board or scrap wood so that it retains the glue.

[Craic]

Anthony,
I am not a home builder myself. Sanding those delicate joint contours must be tedious.
I would think you could speed up fitting the interlocking finger joints somewhat if you use a handheld mini-drill with a router bit (lookup http://www.swallowboats.co.uk/component/option,com_smf/Itemid,52/expv,0/topic,281.0) for smoothing.

[Paul Cross]

Anthony

I'm not a home builder either......But even with some tedious sanding, this looks a lot easier than scarfing the joint.

Thanks for the pics and keep us posted.

Paul

[Anthony Huggett]

I think the great advantage of the finger joint is that the length of the final plank is accurate. With a scarf (I've never made one) it looks as though the final length depends on skill; I would expect some error in the final lengths if I tried.

[Anthony Huggett]

I'm pleased to report that the black PVC sacks did not stick to the epoxy. I was a bit worried about that last night!

[Tony]

Hi, Anthony,
My last home-build was a 4 foot wingspan towline glider from a Keil-Kraft kit - vintage 1965.   I lost it when I forgot to light the de-thermaliser fuse before launching. Watching 6 weeks work with Balsa, tissue and aircraft dope just circle higher and higher down wind rather put me off building anything again ... but stitch and glue, fool-proof finger joints and the current lack of a Lottery win might just tempt me.

How do you rate the BayRaider 17 as a first project, Anthony?

[Ian Cowie]

Hi Anthony,

This looks like it is going to be a fine project.

Do you have a larger workshop when you start assembling.

This method of joining planks looks ingenious and should provide a good result.

Have you considered using acetone to clean up the excess epoxy and thus reducing the sanding later. I like your use of G clamps to get around the width problem of clamping.

Ian

[Anthony Huggett]

I wish I did have a larger workshop! The garage is about 21 x 8 feet, but is adjacent to the house with a single pitch roof, which provides plenty of storage in the garage rafters. I can access either end, and it leads through to the utility room. I might have to use that to lay up the floor/ballast tank top.

The trailer is going elsewhere so I can put a build cradle on the floor, which will be on castors so I can get to one side or the other of the boat.

The buoyant foam for the floor of the ballast tank sheds dust everywhere (whenever you touch it). I've put that in a neighbour's garage for now, hoping to use it all before too long.

The current plan is to cut and join (and seal and sand) as much plywood as possible, taking care to make the planks the right way around (because there's no way to turn a 17 foot plank around without going outside). Then the trailer is going into storage, I will then build the cradle, and start assembling the hull. If things get desperate I'll have to do jobs outside, but given the great British weather I'd rather not.

[Anthony Huggett]

Hi, Anthony,
My last home-build was a 4 foot wingspan towline glider from a Keil-Kraft kit - vintage 1965.   I lost it when I forgot to light the de-thermaliser fuse before launching. Watching 6 weeks work with Balsa, tissue and aircraft dope just circle higher and higher down wind rather put me off building anything again ... but stitch and glue, fool-proof finger joints and the current lack of a Lottery win might just tempt me.

How do you rate the BayRaider 17 as a first project, Anthony?

Daunting, but that's mainly because of the overall amount of work involved.

I think it's important to choose a project that you will want to own when complete, which is why I went for a Swallow Boat rather than other kit boats I could mention, which didn't appeal so much. Though this is my first complete boat build I did put new plywood side decks on my Albacore dinghy a number of years ago, and having owned and maintained various sailing yachts over the years I have some idea of basic carpentry, glassfibre layup and so on.