Figure

Scarfing jig—1:12 slope for all spar-stave scarfs

Wedge of plank-butt to be off, then planed clean \

Clamp prevents slipping of the stock in the jig

Plane rides diagonally on the wedge-shaped runners of the jig.

than the scarfs, exactly the width of the stave, and with waxed paper between caul and scarf (see Figure 18-8). And we'll use plenty of clamps: four C-clamps on each scarf to hold the joint in line, and four of your special spar clamps to spread the load. Leave them for now. You can do no more until the morrow, when the thumbnail test will tell you if it's safe to release the clamps. (If the oozed glue is brittle, the bond is safe 10 handle.)

Good enough. Off with the clamps, clean off the glue, joint the matching staves exactly alike and perfectly square on the edges. Cut that rabbet, as shown in the cross section in Figure 18-9, full length of the forward and after staves, to stop inward movement and help with alignment of the side staves during the final assembly. (Or, if you wish, you can attach temporary cleats to the side staves to stop that inward and uncontrollable skid.) Fit a solid plug, 2 feet long, at the top end where the main halyard sheave and all the masthead rigging tangs come together; fit another at the butt end, long enough to reach above the halyard cleats, winches, and main-boom gooseneck. Run through a dry dress rehearsal; rally your helpers, trained in the ways of clamps and brushes; mix two quarts of glue, and go to it. Wet both surfaces, work fast, set up those clamp bolts as if you had a built-in torque gauge in your right arm—and let it set for 24 hours. While you wait, you can soothe your impatience by gluing stock for a 3-inch-diam-eter solid boom, or a tapered mast for your peapod.

When you can wait no longer, strip off the clamps and taste pure joy. You've got all the time in the world, now, to clean, shape, and round that beautiful thing, and every move can be sheer delight. And when you've got this one done (except for the sheave, spreaders, tangs, sail track, and a few other things the plans call for), you'll know about all I can tell you about sparmaking. Stay with that one-in-twelve slope for all scarfs; smooth surfaces to join; keep wall thickness no less than one-fifth of the diameter, whether round or box-section—-and that's about it.

Figure 18-10 shows various cross sections using four staves, or twro thick ones hollowed out and glued together. You can, of course, build up that thickness by gluing two and two together, and then dig out the valley in each of these built-up halves. Use your adjustable-depth circular saw to make nicely calculated lengthwise scores, close together, four passes for each setting, down the steep sides and across the bottom of the fjord. Break out the wafer-thin leaves with a gouge, and smooth the hollows with a round-faced plane. You will, of course, have stopped the hollowing short of the ends, for built-in plugs, and you could also leave a solid section where the spreaders will thrust and shroud-tangs will bolt. Glue these two troughs together, and round off the outside in the usual wav.

If you have tools and patience to handle the scooping-out process, you may decide that this is the simplest and most satisfactory way to make a hollow spar. And if, in the glory of your new-found confidence you decide to try an eight-stave construction—go right ahead, but don't expect me to help you. I have trouble enough handling four. (I will, though, pass on a rumor I heard that saddles and giant hose clamps are the answer.)

Pads to distribute pressure

Ye x 12" threaded rod

V/z x V/2 x 12" oak figure 18-7 Homemade spar clamp

Pads to distribute pressure

Spar clamps set about a foot

Slot saves time in opening.

Ye x 12" threaded rod

V/z x V/2 x 12" oak figure 18-8 Scarf-joining a spar stave

Scarfs to be mated

Scarfs to be mated

Spar clamps compress the joint.

Waxed paper, newspaper, or scrap polyethylene

C-clamps are set first to hold scarfs in alignment and to prevent slippage.

Spar clamps compress the joint.

Lengthening a spar

Once upon a time, a man I knew shaped a magnificent round spar for a new catboat, and he measured off the length from the top (the stick was several feet too long) and cut it off— on the wrong mark, so that it was 2 feet too short. Some appropriate words were spoken, and another member of the crew, under better emotional control, cut the remains into 6-foot tapered rolls, which are ahvays handy around a boatyard. No great harm done, you may say. You'd be wrong. That man told me with tears in his eyes that he'd never since been able to pick up a crosscut sawr without his hand trembling. The pitiful part of this is that it was completely unnecessary. Had he known what

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