The Ballast Keel

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C >ne of the most fascinating and heartwarming ihuigs about the boatbuilding business is the »niversally friendly helpfulness of the many *.-itors we have. They are not, for the most : .¡rt, people with, as you might say, an axe to _::nd—or a plane to be adjusted, or even a heck to press into our embarrassed hand as >wn payment on a new design. Not at all. i hey come because they like us, and they like ihe smells around the shop that speak of cedar •havings, wood preservatives, and certain little xeatures who have discovered good digging inder the boiler.

These visitors are not ignorant. They are wen students of yacht design and boatbuilding, ever willing to help with a bit of friendly advice, or a quick demonstration of how Manny •■• hose shop they visited on last week's day off) fits a beam in less than half the time we're likely 10 need for the same job. And when they say, 'Do you really think this stuff is fit for planking"—or, "My gahd, don't tell me you're -till using iron keels and galvanized bolts!"— we feel properly grateful and almost at a loss for words. Almost, but not quite.

Therefore, having arrived at the subject of ballast keels, and in full awareness of my vow to avoid contention concerning matters of design, I'd like to attempt to justify that hunk of weight, to describe what it's made of and why it's shaped the way it is.

Outside iron

There are still some who, steeped in the lore of Friendship sloops, sandbaggers, Brixham trawlers, and seasickness cures, maintain that all ballast should be inside, anyway. I have given up fighting the battle of sail-carrying power ("After all—admit it—if you want to go to windward, you turn on the engine"), and have even slopped pointing out that lead inside is fully as expensive as lead outside, and terribly dangerous if the boat rolls completely over. I even dare suggest that some of those encap-sulated-birdshot ballast systems in the plastic-boats will bear watching, too. All I do now is give the inside-ballast man a flatiron and suggest he hit the bench with it, twice—once with his hand on top of the iron, and once with his hand underneath. If you have never run a boat aground and feel completely confident that you never will, then this demonstration does not apply; but if you are half as timid and bumbling as I am, you'll be happy in the thought that the weight is already at the bottom of the pile.

So we'll put the ballast outside and keep the bilge airy. But why iron? You can melt lead yourself, in an old iron bathtub over burning automobile tires, and ladle it into a wooden mold. If a foundry casts a lead keel for you, in a sand mold, you need only provide the wooden

Sailboat Keels Plans

figure 3-1

Half-breadth of sternpost

Rabbet at 6

Cardboard template for half-breadth of ballast keel at 5

Half-breadth of stem face 3

Enlargement of body plan

Rabbet at 5 of casting at IVz" below rabbet

Half-breadth of top of casting at 5

Bottom of ballast keel at 5

Profile of the ballast keel in the loft plan pattern and more money. The weight, can be lower, less bulky, more easily located at the correct fore-and-aft position. It won't rust. The bronze bolts through the lead shoe are more reliable than the steel bolts you'd use through iron (and just to be cautious, I'll include stainless steel in my doubts). And, as someone always points out, you can take lead ballast off anytime, sell it for scrap, and get your money back.

In the face of all this undisputed evidence in favor of lead, what can we say in favor of iron? Well, first, it's less expensive, if compared to the foundry's price for a lead keel, or if you add your own extra labor cost in making a negative pattern or mold and doing your own melting and pouring—which, incidentally, can be somewhat hazardous, if you get careless; I have scars to prove it. But cost is a poor argument. The best money in the boat is the money that buys outside ballast, so don't begrudge it. Get the best material, and get enough. In my case, get iron. Design the boat so that only iron can hit those adamantine ledges—and slide smoothly off, undistorted. Design it, furthermore, so that you don't have to carve out large mounds of outside deadwood, where vile worms will dwell soon after you scrape the paint off.

Think how strong the boat must be, with stem, sternpost, and all points between tied directly to that unyielding base. Neither thrust of mast nor two-point support from a storage cradle will ever bend that foundation.

The solid pattern method

Whether your design calls for lead or iron, slabsided or streamlined, someone has to make a pattern for it. Patternmaking is a craft that demands a very high degree of skill, precision, and ingenuity—if you're dealing with something like a matched pair of water-jacketed engine manifolds, or a massive frame whose finished dimensions must be accurate to tiny fractions of an inch. But such skill is not essential to the making of a ballast-keel pattern, and you have to make a pattern anyway—so let's get at it.

If your design calls for the simplest form— parallel-sided for the greater part of its length, tapering very slightly from top to bottom to give the pattern "draft" so it can be lifted out of the sand—then the problem is very simple. You can make the pattern solid, preferably of white-pine timber sawn to the maximum thickness required at the top of the casting. Pile it up, and

-Se "solid

SJttern"

method

-Se "solid

SJttern"

method

Pine log is sided to maximum width of the ballast keel (and then some).

Station lines and profile of the ballast keel are laid out along one side.

Perimeter is cut straight through, square with the flattened face.

Top surface is hewn flat, planed straight, and given a centerline. Station lines are run across.

Pine log is sided to maximum width of the ballast keel (and then some).

Station lines and profile of the ballast keel are laid out along one side.

Perimeter is cut straight through, square with the flattened face.

Top of ballast keel is laid out and faired through with half-breadths taken from the body plan.

Top surface is hewn flat, planed straight, and given a centerline. Station lines are run across.

Ballast Keel

Hewn bottom surface is similarly marked with centerline. Station lines are run across. Bottom edges of the ballast keel are laid out and faired through.

Sides are hewn straight down between the perimeters laid out for the top and the bottom of the ballast keel.

Hewn bottom surface is similarly marked with centerline. Station lines are run across. Bottom edges of the ballast keel are laid out and faired through.

Sides are hewn straight down between the perimeters laid out for the top and the bottom of the ballast keel.

Templates trom the loft plan are tried along the station marks in spots cut by chisel to light-tight fit.

Areas between the station spots are hewn off and planed to fairness. Trying batten is applied along the pattern to check for high spots.

Templates trom the loft plan are tried along the station marks in spots cut by chisel to light-tight fit.

Areas between the station spots are hewn off and planed to fairness. Trying batten is applied along the pattern to check for high spots.

cut it to the profile you laid down on the floor. Taper the pattern for draft by running it through a single-surface planer, with a batten tacked along its lower edge. Double the thickness of the batten, of course, when you turn the pattern over to do the other side. (Or lacking a surface planer, you can do this tapering by hand plane. A taper of V* inch to the foot is enough.)

Taper the ends of the pattern as necessary, and shape the entering edge as shown in the lines drawing. If your designer has been paying attention to the findings of the tank-research men, he will be very fussy about this, probably demanding a curve like a snubbed parabola, rather than the flat-with-rounded-corners, full half-round, or blunt knife-edge that were considered proper by various designers at various limes during the past hundred years. Laminar flow, width and location of maximum chord, acceleration of water particles, minimization of the areas of turbulence—these are all sud-

figure 3-3a

The "lift model" method

Wooden Boat Building Drawings Plans

The "lift model" method

Strip of building paper is laid parallel to the top of the ballast keel in the loft drawing profile.

Ends of the casting and the station lines are projected squarely to it from the top of the ballast keel in the profile.

Where the marked lift lines cross the centerline at 5 in the loft body plan, their half-breadths for 5 may be taken directly with and applied to 5 on the paper strip.

At 6, 4, and 3 the heights of lift lines crossings must be projected back to the centerline before the half-breadths of the lifts can be taken in the body plan.

Lift thicknesses are marked into the loft profile of the ballast keel.

Wooden Ship Ballast

denly very much to be considered, and you can be sure that your designer had them in mind when he shaped those lowermost waterlines.

For the moment, let's ignore the problem of core prints, lifting eyes, and surface finish, and discuss instead the building of a more compli cated pattern—for instance, the one required for our example.

There are at least three ways to do this job. The first and most primitive (and by far the most difficult, in my opinion) is to start with an enormous baulk of timber and whittle it to

Lifts sawn out and fastened together figure 3-3e figure 3-3d

Ship Keel Ballast

Lipped adze for smoothing

Gouge adze for roughing

Smoothed to the bottoms of the valleys, and faired fore and aft with plane figure 3-3e

Smoothed to the bottoms of the valleys, and faired fore and aft with plane

Lipped adze for smoothing

Lifts sawn out and fastened together

Gouge adze for roughing shape, using templates lifted from the section lines in the body plan as guides. (Figure 3-2 illustrates this method step by step.) An old-time sparrnaker, good with broadaxe and adze, could possibly do an acceptable job by this method. So could Michelangelo.

The lift model method

Instead, suppose we build this pattern as if it were a lift model—using layers of 2-inch plank, sawn to shape, pinned together, and faired off with adze and plane, as shown in

Sailboat Lofting

Figure 3-3. This makes much more sense. This method will eat up a lot of good pine plank, and will require some additional lofting and much hand planing, but it's simple, foolproof, and entire satisfactory (and the molders in the foundry can ram the pattern to their hearts' content and never dent it a bit).

Back to the lines on the floor, then. Tack down a fresh piece of building paper—longer than the pattern you're going to make, clear of the casting in the body plan, and parallel to the keel. Draw a centerline on this strip, exactly

Figure 3-3. This makes much more sense. This method will eat up a lot of good pine plank, and will require some additional lofting and much hand planing, but it's simple, foolproof, and entire satisfactory (and the molders in the foundry can ram the pattern to their hearts' content and never dent it a bit).

Back to the lines on the floor, then. Tack down a fresh piece of building paper—longer than the pattern you're going to make, clear of the casting in the body plan, and parallel to the keel. Draw a centerline on this strip, exactly parallel to the top of the casting (Figure 3-3a). Mark this line where each station ordinate crosses it, and at each end. Draw a line square across at each mark. Now lay off and pencil in the half-siding of the rabbet line in the plan view, and extend it all the way to the after face of the sternpost. You will not use this rabbet line in shaping the pattern, but it will serve as a guide to the lines you are about to develop inside it. Each one of these lines will represent the top surface of one of the lifts that will make up the pattern.

Go back to the body plan; intersect each ion line 1V2 inches below the rabbet height that station; take these widths out from the terline; then lay down this line in plan . as you just laid down the rabbet line, is line you have just drawn, of course, repre-ts the top of the casting, and the top of such J wood as maybe used to continue the shape the casting all the way aft. Now go through 5 process again to get the shape of the top of second slice down from the first exactly the ckness of the stock you are using. (This 1 ckness is purely arbitrary and depends solely what you can get. Probably 1 '/8-inch thick-arss is the likeliest.)

You will, of course, note that the forward after ends of each lift are determined by their intersections with the profile, except at e top of the forward end of the pat tern, where

• lifts are cut off square to butt against a

• ~;all fairing piece. All lifts will have the same

- -.If-siding at the line of the rudder stock, even . • their points of intersection move progres-

ely forward (Figure 3-3b). Continue this laying down, then, until the tnth, tenth, or whatever slice appears as a

• iort little pad at the toe of the profile, and

• pare to reproduce all these flats, double, in >od. You can use the nailhead walk-about

- .stem for printing the half-width and center-ne, and develop the other half with measurements and a batten on the other side of the interline. Be sure that the centerlines are

-vactly right, and mark at least one station on ach lift so that you can locate them in their roper fore-and-aft positions.

Saw the lifts out right to the line. Pile them :p, upside down, holding each lift to the one below i t with glue and plenty of 3-inch number . 2 screws. The pattern should now look like Figure 3-3c—corrugated, but showing promise. All that remains to be done is to work the pattern down to the lines until it is perfectly fair and smooth, when it will be ready for core prints and three coats of shellac.

Right now, with this rough thing confronting you, you need a shipwright's lipped adze and some confidence in the use of it. If you ^an't find an old adze, complete with handle, order a new one from your ship chandler and fit a handle yourself. (I know of one book on boatbuilding that discourages any amateur's hopes of mastering this tool; but the text's accompanying drawing, depicting this strange and wonderful instrument, shows the handle in backward. If the author attempted to use it like that, he comes by his pessimism naturally.) Actually, a good adze is one of the easiest of all tools to use; it is precise, powerful, fast, and far safer to use than a hammer. So get one—or three or four assorted sizes and shapes, if you can; Figure 3-3d shows how a gouge adze is used for roughing, and a lipped adze for smoothing— and practice with it for a few minutes. Sit down, holding the end of the handle so it is anchored in your left hand against your tummy. Lift the handle with your right hand and chop clown gently. Cut across the grain, seldom with it. Slide your left hand down your front as the cut moves down the timber.

But shun the broadaxe, my son, because that is a tool that's hard to master. I can still recall the dismay I felt, at the age of six years, when my father gave me my first real chopping axe and told me that you have to start really young if you're ever going to be a good axeman. A fine thing to spring on me at that late date! There I was, practically grown up, and just starting to learn. And I was right. I never did become a good axeman, but I can cut out wooden gears for an alarm clock with an adze. So can you, by the time you've got that pattern roughed off to the hand-plane stage.

The frame-and-plank method

I promised three ways to make this pattern. The third way is to build it like a boat—framed and planked, as in Figure 3-4.

The top of the pattern should be cut from 2-inch pine plank, just as you laid out and cut the first lift in the above process. Mark the centerline and stations on its under face, and lay it upside down on at least three horses. This represents your keel, so be sure it's straight. Clamp the plank to the horses so it will stay that way from now on.

Go to the body plan, and there lay out the shapes of the stations in way of the ballast. From these you will make up solid bulkheads, cut to shape from heavy pine boards. Each one will be 2 inches short at the top and bottom, and 7/8 inch scant in width on each side. The top edge of each will be cut to the angle of the drag (downward slope aft) of the keel. Set these upon the upside-down top so they are centered exactly, toe-nailed in place, and braced at the correct angle.

Now fit, brace, and fasten a false nose, as shown in Figure 3-4a, so it is roughly parallel with the forward profile of the ballast casting and about 6 inches aft of it. You must cut off the

Core print—upper face of the ballast keel casting

These produce IV2" depressions in the top face of the sand mold to receive the pipe cores extending upward from the lower part of the sand mold during the casting process.

number 3 bulkhead to allow the passage of this false nose from the underside of the plank top to the straight line determined by the bottoms of the bulkheads on stations number 4 and number 5. ("Bottom" here means, of course, the true lower ends, which are at the moment facing upward as this pattern is being assembled.) This false nosepiece will be straight sided, and its taper determined by widths at its intersections with the number 3 bulkhead and the plank that forms the inverted backbone. Allowance must be made, of course, for the beveling of that plank, as shown on station number 2 of the body plan, and for the '/s-inch boards that will be bent around, outside the frames and the nosepiece, to constitute the side planking of this pattern (Figure 3-4b).

Before planking, however, you must fit intermediate frames a foot apart, between the station frames already in place (Figure 3-4b).

These either can stand plumb to the backbone, or be raked to match the station frames. To get their shapes, you will, of course, work to two curves, determined by battens bent around the station frames, top and bottom. When you fasten them in place, align their center marks exactly to a straightedge tacked to the lower ends of the station bulkheads.

Now to plank the sides of this pattern: Start with a straightedged board, about 10 inches wide and 16 feet long, and clamp it to the number 4 bulkhead, with its lower edge up 3 to 4 inches from the backbone. Do the same on the other side with an identical board. Pull the forward ends together until you can clamp across and squeeze the false nose between them, with their lower forward corners almost touching the backbone. Go aft, and pull the after ends together. The lower after corners should be just clear of the backbone, if your guess at

Sail Boat Keel Building

Core print—on the lower face of the ballast keel pattern

These produce depressions In the lower part of the sand mold to accommodate the square head of the sand core, which aligns the pipe core within the sand mold.

number 4 was right. This is, of course, too much to expect; so loosen the clamps at number 4, and move the clamped-together after c-nds up or down as may be necessary.

The purpose of all this double-action bending is to maintain equal pressure on both sides of the bulkheads, and thereby avoid pushing anything out of place. Now set your dividers as wide as they will go, and scribe lines on these two boards exactly equidistant, at all points, from their final resting place on the backbone. Reverse the clamping-on process, and saw one out. Theoretically, the other one should be an identical twin; if a great discrepancy appears, try to find out where you went wrong.

Bevel the edges of the boards to fit against the backbone; reclamp; mark for alterations in the fit, and for the cuts to be made flush with the forward face of the false nose and in the same plane as the bottom ends of the bulk heads; take it all apart again, and alter and cut; reclamp, and fasten the boards to the bulkheads with 2-inch number 12 screws. The second boards, which will cover the remainder of the sides, go on next. Dress off the edges so they are exactly straight, right to the nosepiece, and fit to them the 2-inch plank, which will eventually be rounded off as the underside of the pattern. Cut its forward end flush and in line with the forward face of the nosepiece (Figure 3-4c).

Now build up the laminations of 2-inch plank, against the line of the false nosepiece, until you have enough material to make the shaped entering edge and toe of the pattern. When fastening these one to another, bear in mind the shaping that is to be done, and try to keep the screws clear of the danger areas. Use a drawknife, planes, and Stanley "Surform" wood rasps for this final shaping, getting the contours from plywood templates taken off the figure 3-7a

Loose holes reamed with galvanized 20d spike

Scored centerline 1" auger hole

Loose holes reamed with galvanized 20d spike

Scored centerline 1" auger hole

20d spikes, shanks (bright) driven flush into tight holes figure 3-7b

One-half of the finished core box

One-half of the finished core box

lines on the floor. Cut the after end to the exact line of the rudder stock, leaving the jog at the bottom as shown in the construction plan.

We still have to fit core prints and lifting-eyes, make a core box for the bolt heads, and apply the final finish.

Core prints and the core box

The core prints, of course, leave their marks in the two parts ("drag" and "cope") of the sand mold that will be packed and rammed around this pattern at the foundry. (This explains the use of heavy scantlings for patterns. Foundrymen will not accept a pattern made of thin plywood, which will bulge inward under the pressure of the ramming.) These prints must match exactly the cores they are to accommodate—in this case, standard 1-inch iron pipe, which measures 1 V>e inches outside diameter. For the top prints, therefore, plant-out a 2-foot length of round stock, of this diameter, and cut it into 2-inch lengths.

Turn the monster right-side up, and lay out the locations of the bolts, as shown on the construction plan. (In this design, all bolts are on the centerline, and all but the aftermost one are square with the line of the keel.) Bore a shallow hole, about V2 inch deep and 1 Vi6 inches diameter, at each mark; tap one of your round pegs into each pit, and fasten the peg with one 3-inch number 12 screw right down

Sand core made with the combined halves of the core box

Sand core made with the combined halves of the core box

Lifting eye, "bolted through pattern the middle (see Figure 3-5). There's a good chance that the foundrymen will want these top prints out of the way during the first half of the molding, and the screw fastenings can be removed and later replaced without tearing anything up.

Now turn the pattern over and fit the bottom prints (Figure 3-6). These are blocks 2 inches square, to take the square cores which will form the pockets for the bolt heads, and, of course, center the lower ends of the pipes. They must stand up straight on the hillside—that is, their sides must be precisely parallel to the line of the bolts—and they must be carefully located, on the centerline, directly under the top prints. If you start with stock 1 'A inches thick, you will have enough wood left after fitting to the slopes.

Now for the core box. Cut two pieces of pine exactly 1 by 2 inches, and about 8 inches long. Cut a groove about Vi6 inch deep by Ve inch wide lengthwise down the center of one face of each piece. The easiest way to do this is on a table saw. Clamp the two pieces firmly together, groove to groove, with their edges matching exactly. Start the worm of a sharp) 1-inch wood auger in the double groove, and bore lengthwise (with the worm following the groove) a distance of 2 inches. Without disturbing the figure 3-9

Table Saw Clamp

1" pipe core

Sand core from the core box

Lower core print impression

Upper core print impression

1" pipe core

Sand core from the core box

Lower core print impression

Upper core print impression

Cross section of the founder's sand mold clamps, drill four s/i6-inch holes squarely through the two pieces to take slip-fit pins. Remove the clamps and spin a headless 20-penny galvanized spike through the pin holes in one of the two pieces. Cut lengths of plain 20-penny spikes for the pins, 1 V'2 inches long, and drive them through the tight holes in the other piece (Figure 3-7a). Clamp the two pieces together and build a wall 4 inches high around the bored end, made up in two parts that separate on the same plane as the first two pieces. (See Figure 3-7b.) Take the core box apart, smooth all the inside surfaces, shellac, smooth some more, fill any crevices with beeswax, shellac again, and it's done.

The foundryman will very likely snort and tell you he has a much better core box in the core room, but don't let that bother you. If you hadn't brought this one, you would have been treated to a demonstration of shocked pity for your ignorance. Quite seriously, though, if you don't know much about this business, make friends with the foundry boss and watch the molders at work. Theirs is a fascinating art, and they'll teach you some things you'll need to know hereafter about patternmaking.

And, although they won't expect it, they'll be happy to see the pair of lifting, eyes you are about to install in the top of your pattern. Remember, however, that if one of these eyes pulls out, after the crane has lifted the pattern clear, and the heavy end drops down and ruins a day's work, you will wish you were not around to hear the comments. So install the eyes this way: Bore a 7/i6-inch hole all the way through the pattern, from top to bottom; countersink at the bottom to take a washer and 3/s-inch nuts; countersink at the top so that, with the top of a Vs-inch threaded bolt just flush, there'll be room to drop over it an upset shackle

Keel Lead Bolted

Open female ballast keel mold for lead made of Vs- by s/4-inch flat stock, with a hole drilled through its crown, and a full nut to hold it on (or buy a pair of Vs-inch eye nuts). This assembly is pictured in Figure 3-8.

Female mold

A female mold, shaped, rounded, and flared, into which you can ladle your own bathtub lead, is built by the same contour system as described in the second method above, but reversed, with wooden walls, well-bolted top and bottom, surrounding the grand canyon, whose sides you will pare smooth with an adze, gouges, round-faced planes, and a disc sander. Make the mold in two halves, split vertically, so you can lay each on its side and really get at it for shaping—and so you can get it off the casting without breaking it to bits. Set the mold level, on a base that will support all those tons without subsiding or leaning. Use dry hardwood dowels for bolt-hole cores. Set the dowels in shallow holes at the lower end, held by well-fastened cleats around the mold at Lhe top (see Figure 3-10). Remember that the dowels will try very hard to float when the lead is poured. Paint the cores and the interior with something that will prevent charring of the wood. We once used ordinary waterglass, on somebody's recommendation, and it certainly didn'tdoany harm.

If I were doing the job, I'd pile and pack sand all around that mold, so that if it sprang a big leak, or a lot of small ones, I wouldn't lose the whole damned shooting match.

Right now (never mind what I said at the beginning of this chapter), I'm beginning to think fondly of a good sailing dory with beach stones under the middle thwart. I heard somewhere that the pink ones are the heaviest.

Catboat Eith Jib

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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.

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Responses

  • subhan
    Can a wooden boat have two keels?
    6 years ago
  • lucille
    What is best material to make a mold for pouring lead for a sailboat keel?
    3 years ago
  • KAIDEN
    How to lay down the keel for a wooden boat?
    5 months ago
  • esa
    Where is the sailboat keel weight located lengthwise?
    3 months ago
  • sabina
    Can you have a full keel without a ballast?
    1 month ago

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