It’s a great day indeed when you remove the molds. But don’t be in too great a hurry; a few things need doing before you break them loose.
I assume that you’ve been properly cautious, with ties across from sheer to sheer in the middle third of the hull (to prevent spreading) and braces between frames below the future location of the sheer clamp in the ends of the vessel, where she’ll try to come together. You should mark a true, pure line, representing the underside of the covering board, identical port and starboard, on the sheerstrake, with due allowance for the crown of the deck. The sheer marks on the molds will help you get this right. Dress off the sheerstrakes to this line.
Be sure to run a pencil line down the inside of the planking, along the business edge of each mold. If you haven’t yet followed my instructions in Chapter 11, I wish you’d roll a strand of cotton into the topside seams, and even do some smoothing above the turn of the bilge, to calm the visitors, but I’m afraid this is too much to expect-so go ahead and yank the molds out. As soon as you’ve finished gawking at the vastness of that hold, we’ll consider the problems of the deck frames.
In its simplest form, the deck frame consists of beams extending from side to side of the vessel, usually spaced about the same distance apart as the hull frames-with various openings left for houses, hatches, cockpits-and damned well fastened at both ends to resist the weight of years and boarding seas. This end fastening has taken various forms through the centuries, ranging from spruce-root lashings, hanging knees fastened to frame heads, mortise-and-tenon joints through the sheerstrake, to the system most of us now use, which I will describe here.
The sheer clamp
The first move is to fit and fasten a timber to the insides of the frames, with its top edge below the top of the sheerstrake by the depth of the beams, and extending from the stem to the transom. This is a simple enough proposition, with only two inherent pitfalls.
You’ll notice the first problem (as I finally did about the third time around) when you lay your concave beam mold across the hull from sheer to sheer and mark on the inside of the frame for the top edge of the sheer clamp at that frame. If the vessel has tumblehome, plumb, or even slightly flaring topsides, that mark must be, below your mold, much less than the depth of the beam. The beam must hit the inboard edge of the clamp. In the forward sections, where the topsides very likely flare decidedly outward and the beams are short, the opposite effect occurs: the inboard edge of the clamp is higher than the outboard and must be notched to get full-width contact with the bottom of the beam. Figure 13-1 shows this effect better than I can describe it.
The second problem crops up in the forward part of the vessel. It’s very likely that the flare of the topsides will demand a humped-up curve, which you may have noticed when you fitted the sheerstrakes. Since the clamp is to be a 1 ½- by 4½-inch timber, you are not likely to get this curve by edge-setting. Perhaps you’ll have to steam it, or even saw it to shape; maybe you’ll split it (horizontally, of course) with a saw cut, back to the point where the timber straightens out and starts curving in the other direction (see Figure 13-2a). The latter scheme works fine, and never mind what people say. By the time you bolt the beams to the split clamp vertically and bolt the frames horizontally every foot or so, it’ll be plenty strong.
Cut the forward end of the sheer clamp to bear snugly against the back of the stem, make the scarf cut (2 feet long, horizontal cut; see Figure 13-2b) at the after end, slide it forward on top of your temporary cross-braces, and haul it out to the frames with all the clamps you can muster. You’ll be happy you fastened the sheerstrake with screws, because you can now back them out and replace them with 3/sinch galvanized carriage bolts. Up, down, up, down-counterbore the bolt holes to set the heads ½ inch into the sheerstrake (fill the holes flush to the planking with polyester putty if you’re going to paint the hull).
Assuming you can’t get stock long enough to make a one-piece clamp, cut a matching scarf on the after piece and spring it to the marks. Lock the scarf together, lay the after end out over the transom, and cut it to bear tightly against the transom frame. Bolt the clamp to the frames as above, and put four vertical bolt through the scarf.
Don’t worry when the croakers say, “She’ll hog, sure’n hell, ‘thout that clamp’s one piece!” Just you wait until we get a shelf into her.
Right now, with the deck plan in hand, you need a benchmark from which to plot your boundary stakes. Lay a straightedge across the hull from sheer to sheer, with one edge exactly centered above the ‘midship station mark on the top of the keel. As shown in Figure 13-3, stretch a string from the center of the stem to the center of the sternpost to get the athwartships center of the straightedge. Measure from this point, port and starboard, to the outside of the planking, and be properly proud if she proves to be no more than an inch wider on one side than on the other. File this information in the back of your mind, or in your notebook if you must, and go on to your main objective, which is to spot two points on the straightedge exactly equidistant from the center, and as far out as is convenient-right at the sheer, probably. Now hook your 50-foot tape or nonstretching wire to the exact center of the afterface of the stem, and proceed to adjust the straightedge until the two points on it are equally distant from the stem, even as they remain equally distant from the center. Check your marks with a plumb bob, from the station mark on the keel; then nail the straightedge to the sheerstrakes, so that it’ll stay put while you lay off all your longitudinal distances from it.
Mark these essential longitudinal distances the ends of the cockpit, the ends of the house, the forward hatch, the centerline of the mast, the chainplates, all of the deckbeams-on the sheerstrake and on the top of the sheer clamp, being very careful to indicate on which side of the mark the beam is to be placed. It’s embarrassing indeed, as I’ve found on several occasions, to discover that you’ve fitted, and fastened, a beam forward of the mark on one side and aft of it on the other. Ah, well-unless a bulkhead lands there, probably no one will notice.
Cutting and fitting the deckbeams
Now, armed with a tri-square with a bubble, dividers with a pencil leg, crosscut and rip saws, chisel and mallet, you are ready to mark, cut, and fasten the main deckbeams, if you have any handy. I blithely assumed a while back that you had a proper beam mold to use while dressing the sheerstrakes fair for the underside of the deck and for marking for the height of the sheer clamp. Use this pattern to mark those fine, sweeping planks you saved out, so that the grain follows the crown of the beam (5 inches of crown in 10 feet of length, or whatever your designer calls for).
I always saw out deckbeams with a lightgauge, well-set, sharp 10-inch table saw or (rarely) with the ubiquitous 7½-inch portable electric circular saw. Either of these tools does a smoother job than the handsaw. Check the sawn beams carefully against the pattern, because they may change shape after sawing.
If you lack sweeping stock to make sawn beams, you can steam-bend straight stock on a form, over-bending enough to retain the proper crown when you take them off the form. Or you can glue-laminate the beams over forms with five plies of a wood that glues well-a process much loved in these times because, we are told, at last someone has come up with a way to make wood a satisfactory boatbuilding material. I almost wrote Viable Alternative instead of satisfactory; if I did, I would have put a trademark symbol after the term …. I druther saw them out, myself. Maybe they won’t be compatible with the Space Age, but they’ll be good oak or locust, and will hold fastenings forevermore, and won’t delaminate, no matter what.
Set up staging inside the boat to match the outside staging to make the sheer about bellybutton high when you climb aboard with your tool kit and one of your long beams. Lay said beam across the boat on top of the sheer planks, exactly over the spot it will drop to after you’ve cut it to length. Clamp the beam somehow, so it can’t shift position.
Look at Figure 13-4 and proceed to mark for the end cuts: Plumb up from the inside edge of the sheerstrake to the top of the beam; plumb up from the inside top corner of the clamp to the bottom edge of the beam (and a little higher); set your pencil-bearing dividers ¼ inch less than the plumb distance from the top of the sheerstrake to the top of the beam; and scribe a line at this distance, above the top of the sheer clamp, on the forward and after faces of the beam. (The “1/4 inch less” is not introduced to allow for errors, but rather to allow you to set the beam into a notch of that depth on the sheer clamp.)
Now mark, on the side of the beam, the angle of the end cut from the plumbed-up mark at the top, down and parallel to the inside of the sheerstrake. Then mark a line on the top of the beam, parallel to the top edge of the sheerstrake. Tread softly to the other side of the boat and go through the whole process on the other end of the beam.
Put the beam down on the staging, kneel on it, and make the following three cuts: (I) end cut with a crosscut saw; (2) underside cut with a ripsaw, working to the scribed lines on the fore and aft faces and stopping at the mark plumbed up from the corner of the clamp; and (3) a little sloping cut to free this piece.
You can now try the beam in place. It should stand ½ inch too high, and this amount you’ll cut into the top of the clamp, so the beam will drop down just flush with the sheerstrake and with a little jog against the inside of the clamp.
I’m happy that’s over with, and that I don’t have to struggle through those directions myself; but you’re lucky to have Sam Manning’s drawings to go by. Please hark to my warning that there are no shortcuts, yet rest assured that you’ll be able to mark one of these beams in two minutes, automatically, with one eye on the bubble, after you’ve done three or four.
Is this not dreary stuff? Fussy, tedious moves advancing little toward this fabric’s final soaring beauty. But when the beams begin to drop into place-one, two, three, without a miss-you can be very full of joy for a while.
Go ahead and fit all the full-width beams: after and forward ends of the cockpit, after end of the house, middle beam in the bridge deck, forward end of the house, and all the beams in the foredeck. Use the beam mold to make sure you don’t have a maverick in the bunch, and fasten them all to the clamps-one 3/8-inch bolt, each end, countersunk, dead center, down through the center, with nut and washer on bottom.
The breasthook, quarter knees, shelf, and blocking will come later. Right now you must install the fore-and-aft carlins that establish the edges of the cockpit and the house. This is the trickiest part of the deck-frame project, and takes some planning.
Your construction half-breadth plan should give the half-breadth of the house from the fore-and-aft centerline at every station. Nail a straight one-by-four on top and on the flat across the hull from clamp to clamp at each station. Stretch your string again and mark exact centers of all these temporary cross members-and while you’re at it, the centers of all the beams you have so far installed. Lay off on the end beams and on these horizontal flats the widths to the inside of the carlin. Now at each of these marks fit and fasten a plumb post, inboard of the mark .. Lay your beam mold against each in turn, as in Figure 13-5, and behold-the inner top edge of the carlin has to land exactly at Point X; you have a fine row of posts to spring the carlin around and clamp against.
Fasten blocks on top of the end beams where the outboard edge of the carlin will lie, and bend the timber around the posts and on top of the end beams. At this stage of the proceedings you’ll want the lower edge of the timber to land on the crown marks. Use your tri-square to mark for the end cuts on this timber just as you did on the deckbeams: plumb up from the point where the top of the carlin will land. This point will be½ inch into the face of the beam to allow for a sloping notch (see Figure 13-6).
Figure out the rest of the angles and cuts from the drawing, remembering always that this plumb business works at both ends, unfailingly, and that any deviation from it spells
disaster. Cut the sloping notches in the beams, cut the ends of your carlin timber to match, and spring it in. Push the carlin down and clamp it with the top edge at the crown marks on your temporary posts; drill for and drive three galvanized 20d spikes at each end through the beam and into the end of the carlin (see Figure 13-6)
Go aft now and fit the carlins for the sides of the cockpit. These are usually straight fore and aft, but they must be dipped in profile to match the sheer. This shape can be determined by the same method outlined above; or you can run a batten on top of the bridge-deck and the afterdeck beams, alongside a piece of pattern stock dropped into the notches in the main beams. Mark a fair profile on the pattern. Saw to the line, and mark your carlin timbers from it. Saw them out and install as above (see Figure 13-7). You are now ready to fit the short beams.
Lay out the short beams carefully, square to the centerline, exactly opposite each other port and starboard. You’ll be happy you did when you install bulkheads, hanging shelves, and deck eyebolts. You will, of course, perceive that the top of the carlin must be dressed off to the crown of the deck. You can do this now or put it off until all the beams and tie-rods are holding the carlin against your attack, but if you choose to defer dressing off, you must be wary of one small effect: Unless you shim up the outboard end of the beam (at the sheerstrake while marking them) to match the incorrect height above the carlin, your marks will be wrong, because one end will have to drop that small bit more than the other to achieve its final resting place.
The boatbuilder’s lot is hard enough without adding any avoidable complications, so let’s dress off now. Saw off the posts to let your plane go by (you’ll have to depress them before you lay the deck, so why not now?) and dress off the top of the carlin to match the deck crown.
As you fit all those short beams, remember to plumb up from a line ½ inch in from the edge of the carlin, the top of the sloping notch; from the inboard edge of the sheerstrake (to give the top of the beam at the outboard end); and from the inboard edge of the sheer clampand to scribe up from the clamp with dividers set 1/4 inch less than the distance the beam must be dropped (see Figure 13-8). Fit half a dozen beams, tack them in position with 5d box nails, and drill and fasten them all at once. I like to use two or three 20d spikes from the carlin into the end of the beam, and a bolt through the sheer clamp, as you did on the ends of the main beams.
The beam shelf
Now let’s consider the beam shelf. This bit of furniture is a flat stiffener fitted around the sheer under the deckbeams, against the clamp. It can be sawn to shape from several pieces scarfed together (Figure 13-9a), or it can be built up with four or five narrow pieces, say 1 ½ by 2 inches (Figure 13-9b), sprung into place, and through-bolted to the clamp and the deckbeams. The shelf may go the entire length of the boat, or it may extend only a few feet forward and aft of the main chain plates. Whatever its length, it must be fitted on its outboard edge to a constantly changing bevel on the inboard face of the clamp.
If you are working with fairly heavy timber for the shelf-for example, a plank 2 inches by 12 inches by 14 feet long, to produce a 2- by 5-inch shelf with a scarf at each end-you will be wise to take a spiling on a light, curved spiling board and note the bevels at 2-foot intervals. You can transfer the shape from the spiling board to the stock, and saw the shelf out and bevel it to a fit that is fairly close before you ever take it aboard the boat. Clamp the shelf in place, scribe for the final fit, remove it, dress to the marks, and bolt it solidly to the beams and the clamp. (There is, of course, the possibility that some adjacent beams might not be exactly the same depth. If you can’t stand frustration and don’t know how to use invisible shims, you shouldn’t be in this business.)
With the beams and shelves in place, you can install the tie-rods. These are very important strength members, especially needed under a caulked deck, and especially valuable as the big guns against those sharp-eyed critics who fret about your cheap fastenings from the carlin to the beam ends.
Get out your long 3/8-inch drill, choose likely spots-about 18 inches from each end and no more than 3 feet apart through the rest of the length-and proceed to drill holes through the carlin, the shelf, and the clamp (Figure 13-10a). Countersink for the nut and washer, of course, on the inboard face of the carlin.
An alternative is to run the rod above the shelf and the clamp, out through the frame and the sheerstrake (Figure 13-10b). This system gives the tie-rod a better angle-one that will make the rod more closely parallel to the line of the deck, that is. This system will require more, and still more, higher bungs in the sheerstrake. It’s a toss-up which way you do it. Just be sure the rods are square athwartships, or you’ll be in trouble when you fit the bulkheads.
Finishing the deck frame
What more must be done before you can cover all this with something watertight? Not much, just the breasthook; quarter knees; centerline blocking between all the beams in the foredeck, the bridge deck, and the afterdeck; blocking to take bolts from the gallows frame, the mainsheet horse, and the quarter cleats; the under-deck bases for the lifeline stanchions, the anchor windlass, the mooring cleat, the backstay fittings, and the eyebolts-and a few more that you’d better pre-plan before you start laying the deck.
Start with the breasthook. This, in my lexicon, is a block of durable hardwood with its bottom surface fitted to the tops of the sheer clamps, the ends fitted tightly against the sheerstrakes, and the forward (short) side fitted against the after face of the stem. The breasthook grain must run athwartships. The top of the block must be dressed off to the line of the underside of the decking. I usually edge-bore this piece before installing it to take one bolt from the midpoint of the after edge through to the forward face of the stem. Drive two bolts on each side down through the sheer clamps, and four good screws on each side from the sheerstrakes into the breasthook-and you can be reasonably sure that the nose of the vessel will stay together (Figure 13-11).
With all your tools up at the bow, you might as well fit the centerline blocking back to the forward end of the house. This blocking need not be the full depth of the beams, and it may vary in width to accommodate whatever deck furniture will be sited over it: a wide-based windlass, the staysail boom pedestal, the king-plank, or the butt joint in plywood decking. Also fit a good plank, wide enough to take the widest-spaced bolts in the windlass, with the forward end against the stem, underneath all the beams and back to the hatch opening in the foredeck. Your big bolts from the mooring cleat, the bowsprit socket, and so on, will go down through this plank and tie everything together. Naturally you must fit chocking between the blocking and the plank so you’ll have solid wood to tighten against.
Move your gear aft and install the quarter knees. These are invariably shown as beautiful grown crooks, dead-fitted to the transom frame and the inside of the sheerstrake, and presumably bearing upon and bolted to the after ends of the sheer clamps. I prefer to tie this comer together with a big hunk of fore-and-aft grained blocking, partly because I lack such crooks. As shown in Figure 13-12, it must be bolted to the clamps, pinned to the transom frame, and screw-fastened from the sheerstrakes, and it must have enough area to take all the odd fastenings from the covering boards, the toerail knees, and all the other things that come together at this busy corner.
I almost dare suggest that the end is in sight.
Locate, fit, and fasten the blocking to take the lifeline stanchions. Ditto, ditto, ditto for the gallows frame, the mainsheet horse (tie this one under the beams, something like the mooring-cleat technique up forward), the backstay fittings, and the jib-sheet track-grain fore-and-aft on all.
Put some posts from the keel to the underside of the main beams, and smooth everything off ready for the decking. As for me, I’m going sailing.