Friday, November 11, 2011

Sole Man

In the now-classic (and outdated) book about the aviation, the Sporty Game, the concept of the "Learning Curve" is addressed.  In manufacturing airplanes, the first airplanes off the line are always the most expensive to produce, since the assembly processes are still being refined and the mechanics are performing their tasks for the first time.  As more and more airplanes are produced, you come down on the Learning Curve and the cost and build time of each airplane is reduced...dramatically at first and finally more gradually until (all else being it equal) is asymptotes.

There are Learning Curves in boatbuilding too.  In the case of PocketShip, there is the manual and several excellent blogs that detail the construction of the design.  As a result of reading these, I am farther down the Learning Curve than those who have gone before me.  I am able to steal ideas from other builders to make my boat better or more easily, and am able to (attempt to, at least) avoid some of the trouble earlier builders have had.  Having built other boats also helps bring you down the Learning Curve, as there are several techniques that I picked up on my Pygmy and Redfish kayaks that I've applied to PocketShip.  Of course, there are plenty of things that you don't learn until you do them, plenty of head-scratching and opportunities for making mistakes.

Take laying the cabin sole, for example.  Dave Curtis' blog mentioned that he used the old deck building trick of using a nail as a spacer to keep the correct gap between the planks when cutting his cabin sole.  I probably would have ended up doing this even if he hadn't written about it, but as it was I didn't have to spend any time at all thinking about how to get the right gap between the planks because Dave's work moved me down the Learning Curve.

To keep the proper spacing between planks, I used the standard "nail spacer" trick used by deckers and PocketShip builders alike.

The first few inboardmost planks were fairly easy...just cut to length.  Even so, it probably took more than an hour each for the first four planks, just because I was working out the procedures to install each board.   This got faster as I learned to start from the middle of the plank and work out towards the ends.  To keep the the screw spacing consistent, I made a small guide just the width of my planks with two holes drilled in it.  All I had to do was line this guy up, run my drill down through the holes and, viola, consistently spaced holes!

Getting started laying the sole.

In order to keep the screw spacing the same, I made this handy little jig.

The first four planks on either side were easy.

After the first four planks thing got tough. Both ends of each plank needed to be cut in both planform and profile to meet up with the hull just right. Figuring out how to mark and make this compound cut was extremely challenging time consuming and it really didn't feel like I was moving down the Learning Curve until I was about halfway through. My general approach was to use a short offcut from a previous plank, mark and cut in in planform and then bevel the edge the right angle so that it would firmly contact the hull. Once I got this right (it was a sometimes iterative process), I marked and cut the real board, using my scrap piece as a guide. I guess I went the measure once, cut twice route.  Initially, it would take me about two hours to get a plank in, though as I came down the Learning Curve, this time would eventually be cut in half.

This is all easier said than done, though.  First of all, figuring out the correct angle at which to cut the plank wasn't all that easy.  The manual wasn't much help and neither were most of the blogs out there.  Sean's blog mentioned touched on it, but I was unable to translate his writing into practice.  So I experimented.  Angle meters, projecting lines, mathematics...ack!  I didn't use the same method twice until the final three or four planks, and by then the method that I settled on was to more-or-less eyeball it and use intuition.  The lack of engineering rigour in this approach bugs me a little, but, hey, it worked.  Cutting was much easier, after one attempt with the miter saw, I switches to the circular saw and never looked back.

Bevelling the planks was even trickier.  Finding the correct angle to cut was quite an exercise...again the intuitive approach ended working out the best, but sadly I only learnt that on the final planks.   Cutting them was even trickier.  After a lot of wasted time with a belt sander and a few dubious flirtations with some crazier tools, I switched to the boatbuilder's ultimate weapon, the simple block plane.  This worked better than anything, but took a lot of muscle power. 

A beautifully beveled board.

It took many trial fits to get it right.
To complement the centerline accent board, I laminated up two more figured maple/bloodwood planks to place outboard.  I really like to look of those pieces!

The outboardmost planks were extra tricky.  Folyptus.  I measured the required length of the plank, along with the location and dimension of it's maximum breadth, and then used a batten to strick a fair line.  After a quick cut with the circular saw, a ton of plane work, and plenty of test fitting, I was satisfied.

It took many hours of work to get this far.  Note the accent plank and the extra-wide plank outboard of it.

After that, I just had to repeat everything on the opposite side and I had a great looking cabin sole.  It took way longer than I expected, but it was all fun carpentry-type work, so that was nice.  And I'm very happy with the way it turned out, appearance-wise.  It is also really comfortable; I sat there quite a while after finishing, enjoying the fruits of my labors.  I even explored what it feels like to lay down aboard. 

After waking up, I took a long batten and struck a fair curve along the outboard edges of the sole and will trim the remove all the planks and trim them back to that line.  Then I'll have to round over the edges of the planks, sand, sand, sand, and then finish the planks. 
Finally finished

With the cabin sole in, I couldn't help but sit back and rest a bit.

This quickly devolved into a slightly more relaxed posture.  How great is it to have a project you can lay down in and snooze whilst building it? 

Using a batten to strike a fair curve along the edges of the sole.

So, that's the story of my cabin sole.  One thing you have to love about boat building is the vocabulary...the formal nautical kind, not the salty kind which also has a place. There's English and there's Nautical English. On a boat, a floor is a transverse structural member that ties frames together (PocketShip doesn't have frames, but it still have components positively identifiable as floors). That which on land is called a floor can either wind up being a sole or a deck on a boat. A landlubbers walls are, of course, called ceilings on a boat. And so on.

Another project I've been working on is laying out the locations for the electronics. I intend to mount the radio and light switched straight on to Bulkhead 2. The breaker panel and battery switch will be mounted on a recessed panel and covered with a little hatch...they're ugly and I don't want to have to look at them when I'm not using them. I also plan to build a little "glove box" storage thingy, big enough of glasses, a wallet, MP3 player or other sundries.

Mockup of the electronics locations of Builkhead #2

Open the hatch to access the battery switch and breaker panel

Recesses Panel for battery switch and breaker panel.

Also, I finally finished and delivered the cradle boat to my friends.  The baby is due Sunday, so hopefully it'll be getting some use soon.  The parents plan to name the bundle of joy "Charity,"  so I call the little boat "S.S. Caritas"

S.S. Caritas, ready to set sail

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