Wednesday 7 March 2012

And so, it has come to this....

So I've not done much on the kayak for a week or 2 apart from look at the garage longingly.  I did say this was a blog about trying to do this with a young family so I guess I deserved this, but with 2 kiddies and 1 wife ill with flu, I didn't really get that far (I know! they've got no sense of timing!).

Aaanyway, first night back in the garage and tonight's job was quite fun - to plot out 2 of the panels, so I guess this is the first "glimpse" of what we're going to be making!  This is effectively an X-Y plotting exercise, but you start by creating a straight baseline to plot your points from.  I scarved the panels pretty straight, but decided to play it safe and created a separate baseline anyway.  This I did with a chalk-line. 

This is my first experience of using a chalk-line, but I needed to make quite a long straight line and this is what everyone recommended.  I used my family's week of illness to buy one of amazon for 2 quid.  I would link it, but it was a bit rubbish so don't bother.  Firstly, I'll give you 2 guesses what it DOESN'T come with - lets think, I'm buying a long piece of string on a winder and ummm, oh yes, no chalk.  Stupid.  Easily fixed - one benefit of a young family is that we have an easel in the lounge.  Ok, yes I admit it, I stole their chalk, I feel bad, sort of, but I've not been able to boat-build dammit!  It was only a little bit! They could have it back, but I whacked it repeatedly with a hammer and chucked it in my new chalk-line!

I digress, back to boat.  I pulled the chalk-line taut and noticed that in places, it hovered a good inch over the wood - this comes of having to build a make-shift 16ft long bench.  Anyway, with a few adjustments, I got it pretty good, then 'pinged' the chalk to leave a mark. 
Chalk sold separately

As the chalkline is new and I've not got a lot of chalk stuck to it yet, I probably can't really blame it for not leaving a perfect line, but to be honest, I was hoping it'd do a bit better.  Anyway I used a long spirit level to firm up the line with a pencil and checked it was straight by stretching out the chalk-line again and also sighting down the length of it.  Hopefully good enough - I'm a bit paranoid about triple-checking at the moment, but that should be a good thing if it works!
Yep, thats the baby monitor by the spirit level :)

Having got my straight line, I had to go and find my plans, as this is where they first come into play.  When you design or build a boat, the plans are 2 dimensional, and funnily enough, are not full-size compared to the boat you're building (I'm told that you couldn't do this even if you wanted to because a printer wouldn't give you an accurate image at that length and you'd get stretch, etc).  You've therefore got a job to do called "lofting".  I first read about this on another blog - "the Unlikely Boat Builder" which I highly recommend and I've followed from the start, but anyway, read this article of John's on lofting if you're interested as its very good.
Here's a shot showing how 3 of the ply panels are layed out, and the offsets for the long panels.  I've removed some of the numbers because these are not my own plans and the purpose is to give you the idea, not to allow you to build a kayak without paying for the plans!

As I said, lofting is the process of plotting out the boat from the plans.  In my case, I don't have too big a job.  Take the boat panel in question as a 2-dimensional shape, and a baseline running underneath it.  Along that baseline, you then plot "stations" which are normally interesting points along that line at which we need to mark a vertical line.  This vertical line naturally will meet the panel at various points, and the plans give the offsets that you need to mark.  Simples!


Next job will be to make up a long bendy batten that I can use (in conjunction with some nails at the marks) to join the points into a fair line.  "Fair" in this context is important - it means that the line follows a good single curve from bow to stern and doesn't wiggle up and down the length of the boat.  I think my current plan is to use a bit more of my scrap plywood to make this up - this is where I get to see whether scarf joints really live up to their reputation of not creating flat spots when bent into a curve - still weighing this one up, but I think it'll be ok, at least to try.


I have 4 panels that make up the lower sides of the kayak - 2 bottom panels (gar-boards if you want to know the boaty term) and then 2 side panels each side.  CLC recommend, for obvious reasons, that you plot the panel out on one panel but cut 2 panels clamped together, thus ensuring the sides of the kayak are symmetrical.

Amusingly, cutting these panels out will actually mean I'm going to start the proper building manual for the kayak.  You can buy kits from CLC (or Fyne boats in the UK) which would allow you to skip what I've done thus far, apart from that you'd have to epoxy-glue a pre-cut scarf in the cut panels.  I didn't want to go that route as I thought it was a good lead-in to the project. 

Summary: One panel plotted out ready for drawing in the curve,  Night all!

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