The "Skeleton In the Closet"

1x4 tacked flat athwartships to establish the plane of the bulkhead along one edge

Perimeter boards and stiffeners fastened together so that the plane of the bulkhead lies along their inner (joined) faces

This is simply a large template ragged together from any thin stock (including pasteboard).


Second 1x4 plumbed downward from the first figure 17-3 "Bud's Favorite"

Use of a spirit level to guide the scribing of a locus of points accurately across a wide distance

1x4 laid flat across the hull

Arrows indicate a constant divider setting (or ruler measurement, or marks on a stick) in determining the distance horizontally that this piece must be trimmed to fit the ceiling tightly.

board, exactly where the bulkhead is to go. (If you or the designer managed to locate a deck-beam at this magic spot, so much—so very much—the better, because otherwise you'll have to pad out the nearest one or insert an extra.) Now get out your trusty plumb bob, and spot for another athwartships l-by-4, to be fitted and tacked to the inside of the ceiling a foot or so below, and exactly plumb under—and therefore parallel to—the upper one. There's your inviolable plane, nicely delineated and strong, to assist when you clamp up your first piece for marking. This piece, in case you may wonder, is a length of clear white pine heart-wood, 12 inches or more wide, with a groove in the inboard edge to take a Winch spline. You may plan to use something else, but I'd rather you didn't tell me about it. (I feel that I'm as broad-minded as Henry Ford, who didn't care what color the customer wanted, as long as it was black. Or Nat Ilerreshoff, who admitted that there are two colors—black and white— that you can paint a boat, but only a dam' fool would go for black. It's interesting to contemplate the diametrically opposite attitudes toward the buying public of our two greatest manufacturing geniuses—one opting for black, and the other for white.)

So you've got this fine piece of lumber, rough cut as in Figure 17-3. moved outboard as far as it will go, and in place. Let's indulge in a little fantasy here: If that board were a flat sheet of wax, and all the parts of the boat were hot enough to melt wax on contact, you could slide that slab of wax exactly horizontally, melting as it went, until it reached the distantmost corner under the sheer clamp. (You will kindly assume instant, cooling of boat mass, so that the edges remain sharp and tight.) The key to the success of this maneuver is that the slab moved, without wavering, exactly horizontally, as far as, but no farther than, it needed to go. So all you've got to do to your piece of pine is predict, mark, and remove any parts of it that would prevent its reaching that corner under the sheer clamp. You can't, by any stretch of imagination, expect to do this marking job accurately enough with scribers alone, freehand. You need, in addition, your sliding-blade tri-square, a good level, and a bevel square.

Look at the picture. That inboard edge is exactly plumb, a bit taller than the height required when it has moved outboard to its final resting place. Now, with sliding-blade tri-square level, mark lines exactly horizontal, on the face of your workpiecc, from all salient points in the profile of the cave: two or three arbitrary spots on the roof; top and bottom corners of the clamp; top of the hull ceiling under the clamp; a dozen different spots down the curve of the ceiling. And now your dividers become useful. (You can get the same result with a folding rule or a thin stick with a pencil mark on it.)

Set your dividers to (or measure) the distance from the outboard edge of the workpiece to the remotest point under the sheer clamp. Mark this exact distance out, on each horizontal line, from its point of origin (corner of the clamp, the spot on the under surface of the roof, whatever.) Join these points, as proper, writh straight lines or fair curves—and saw to the marks at the proper bevels.

And that's all there is to it. This direct, marking technique works horizontally, as above, or vertically, as for a deckbeam, or diagonally, for that matter, if vou lav off all your t ' * * »

identical distances exactly parallel on the line of travel. Get this principle firmly fixed in your mind, and you are fully equipped to handle almost every problem that arises. After all, there are only three moves in boatbuilding: mark a piece, cut it to shape, fasten it to another piece. Keep doing this 'til there she sits, looking as if she were alive

Which brings us to the second piece in that bulkhead. You can measure the length of the plumb edge, lay off the angles at the top and bottom on your stock, make some slight, educated allowances, cut and trim to fit—no great job, with no jogs or other intricacies.

Or you can make a skeleton pattern, like a hockey stick with a blade at each end. And fit another, and another—under the carlin, up the inside of the house coaming, marching inboard to the door frame. Tack the bottom ends to the ceiling, remove the lower athwartships l-by-4, fit the fashion pieces (1V2 by 1 V2 inches, screw-fastened to the ceiling and bulkhead staves)— and take the whole damned thing apart to insert the splines. If you remembered to mark a mirror duplicate of the first piece, you've got a good start on the twin bulkhead on the other side of the boat. Don't worry if they look frail at this stage. They'll have horizontal cleats all over them, front and back, to hold bunk tops, galley benches, bookshelves, chart table—and they'll be stiff enough, under this mutual aid program, to support all the rest of the joiner-work in the boat.

So what are you waiting for? Get in there and fit those bulkheads.

The log is rolled and dogged securely for vertical hewing of each face.

Axes of the log are first drawn plumb and level through the pith at both ends.

Spirit level

The spar's maximum girth is laid off in a circle centered on the pith.

Axe work is guided by a line stretched tight between corresponding marks at ends of the log.

Spar log made 8-sided without squaring

The quadrants are halved for the 45° lines (also laid out on both ends of the log).

Was this article helpful?

0 0
How To Have A Perfect Boating Experience

How To Have A Perfect Boating Experience

Lets start by identifying what exactly certain boats are. Sometimes the terminology can get lost on beginners, so well look at some of the most common boats and what theyre called. These boats are exactly what the name implies. They are meant to be used for fishing. Most fishing boats are powered by outboard motors, and many also have a trolling motor mounted on the bow. Bass boats can be made of aluminium or fibreglass.

Get My Free Ebook

Post a comment