By Paul Austin - Dallas, Texas - USA

The Least Boat: Part Two

To Part One

Last time I proposed a design with a flat bottom. While the sides were flared for rowing, still it was a squared pram style boat. Now let's look at lapstrake boats. Maybe we can find a way to simplify the building process. This will be hard to do. As I said before, these lapped boats must be attached along their sides from stem to stern. That takes fine planning for the shape of the plank. Unfortunately, to turn the hull from horizontal at the keel to vertical at the bow means the planks will have to change their exact shape.

The key to this shape is creating the sharpest turn of the bilge above the waterline. That saves so much fric-tion. It also enables the planks to draw the water back alongside the keel as the water proceeds aft. Below is the Herreshoff H-28, with the waterline in red:

Francis Herreshoff wanted to keep the water under the turn of the bilge. The two waterlines inside the red line are parallel waterlines, designed to encourage the waterflow back to the keel. When the waterpressure is on the keel, just the slightest touch of the tiller will turn the ship. Herreshoff designs are known for their perfect balance.

The problem is this style requires a keel-based building process, and that needs skill, tools, space, and time. The easiest boat to build in this keel-based style is probably the Atkin Pixie, at 14 feet.

In fact, you could put some curve into the stern and the frames for a perfectly nice lapstrake hull. These pro-portions are just right. It reminds me once again that shape, proportion and balance are more valuable than the building style.

Stitch and glue requires plenty of glue, ties, and tools. Clenched nails takes a ladder, lots of frames, being able to reach inside while you hammer outside, and plenty of hand strength to clip off the nail heads. Then the nails have to be completely covered on the outside of the hull. Glued lap takes many clamps, fasteners which have to be removed, their holes filled, and plenty of frames. So you can see what you're up against. For a better boat, more work; with less work you get less performance.

In this style, six panels is the least you can have and still have the boat behave like it should. But making the bottom flat means the bottom chine is in the water, creating all kinds of eddys. The only way to obviate this is for the bottom side panel to lay about 15 degrees above horizontal, softening the angle. The Nutshell Pram does this, but it requires all kinds of extra work to make the entire design work.

I haven't found a radical way to simplify the process of lapped sides. But maybe we can find some small ways to create simpler steps, at least in a few places.

The great advantage of a curved hull in a small boat is to create more room without settling for a fat slow wa-terline. Having the topsides hang over the waterline but not in the water gives us room without ruining the performance of the craft. The best example I've ever seen is the Warren Messer 9.5 Laura Bay. Two of its' hull panels are beautifully above the waterline.

However, Laura Bay needs eight panels and thousands of ties. This can't be avoided without altering the shape of the panels to the point of ruining the boat's performance.

Can we simplify construction any on a multi-panel boat of our own? Not entirely, although there are a few things we can do. First, the set up. Stitch and glue requires a flat surface, spacers, and the ability to align the sides squarely. It's similar to the old WAAM (see Least Boat Part 1), only you're wrapping the sides vertical-ly before you glue them into the shape you've created. Warren has done a great job of explaining stitch and glue in the six part article on Laura Bay. What he has to say cannot be improved upon. Plank on frame build-ing needs a support structure, braces, many frames, battens and a flat floor. The problem with plank on frame is that it is a big boat technique brought down to a small boat. Maybe we can make some adjustments to it, for small boats.

The first is the frame setup. Here you can see all the parts needed to adapt shipbuilding to a small boat. Re-ally, all of this may not be necessary--

You can see the frames have to be rigidly attached to the flat floor because the rocker of the keel is so great. This is a style which makes rowing and sailing possible. But in the past, round bilged boats were put together with a straight keel. That made it possible to build them right side up, putting less strain on the men who built them--

This is the 14 1/2 foot sterrnboat for the Revolutionary Baltimore Clipper, Lynx. It was built heavy, for sur-vival on the high seas, with a stout straight keel. I once saw a picture on the internet of four men standing around a table four feet high upon which they had built their skiff at 20 feet with a straight keel. The photo was taken back in the days of 5/8" planks as standard. You'll also notice very little sheer, probably to keep the ocean waves out of the boat when at sea, but it also makes the sheer panel strong.

The two other techniques for fastening frames is to nail them to a floor, or hold the keel down from above. Dory builders have been building their boats upside down, bracing their bottom panel from above for years. It gives the same result without the nails and without having to level the floor. You can make alterations if a mistake is realized without tearing the whole structure apart.

Now we come to the bow. The big ship technique is a curved bow in four parts, with two stopwaters. Plenty of work, and precision work, too. Here is a copy of the typical big ship bow, with a dory bow on the right--

I'll take the dory bow. Simpler with plenty of strength. The bottom panel can be attached to bevel the lead-ing edge before the outer stem is put on. Now with round-bilged hulls I like the bow to be flat for at least the first frame before the deadrise begins. I think this is quite compatible with a strong breasthook, holding the planks right where they should be.

This is the simplest system I've seen. It is designed to perfection in Warren Jordan's 10 foot lapstrake Dul-cibella,

A keel system with fewer pieces is below. It's not as strong and requires either through bolts or glue. It was used on plenty of deadrise sloops in the 1950s.

This style has plenty of advantages, one being it can be done without power tools, just patience and sandpa-per or a little plane. If your carpentry isn't just right, glue fills the bill. You can use clamps except where the frame sits; there nails or screws will do. The main thing to consider is the width of the outer keel. If you plan on adding a centerboard slot, the outer keel will need to be the width of that slot at least. I'd much rather put a centerboard slot on top of horizontal solid wood than angled plywood with epoxy. It's just the way I was raised.

With beveling the battens, I don't know of any better way than the tried and true method of using a straight-edge with sandpaper. Now with spiling, I don't do it the usual way. I go to the store and buy up all the 2x4 sheets of construction paper-all colors-- and tape them together on both sides. I lay them across the frames, tape them down at every frame and draw the lines along the battens on the inside. This has worked for me, although I never did it on a boat over 9 feet.

Here we can take a tip from the masters, the Herreshoff boat yard craftsmen. Where the panels lap, the men didn't just take off some of the edge at an angle, they took off a concave shape. This way, when the screws clamped down the lap, the wood could expand into the curved lap of the other plank. I've exaggerated it here, the concave is slight.

One of the tasks of lapstrake is the gain at the bow. With 5/8" cedar planks these gains were fairly easy to cut, and many a builder has shaved them by hand and eye. They can be eliminated by using a jagged edge at the stern--

But now the bow is a different matter. With plywood, shaving a gain would shred the plywood edge and weaken it. So what we do is like a gain, only along its vertical edge. The plank comes into the bow keel, which is fairly wide as I have shown.

The arrows represent a tiny nail, a long staple might do. Its' purpose is to hold the plank flush while the glue sets. Then I drop glue inside the joint, using gravity to fill it, and then I put a backing inside. I haven't shown the backing, but it is solid wood, a small piece which can be put on first. I stick it in firm enough for the pres-sure of the sides to keep it there until the glue dries. If it isn't a perfect fit, I'm not concerned; its' purpose is to take the pressure off the front of the panel. The front of the panel is not a perfect point since beveling the inside face will flake the point off somewhat, but that's all right. It gives me the opportunity to pour glue upon the front of the panel, protecting it from the bouncing of the water.

I have exaggerated the scale somewhat, to show it. It has taken me more time to draw it up here than it does to make it. I use sandpaper to hand sand the inside face of the plank, going back and forth with the grain. I don't try to get a perfect fit, the nail and glue will fill it in. If you have power tools you can cut an accurate angle, but the forward point will still flake off some. All of this doesn't take much time.

I fill the gap between the backing and the panel with sawdust and glue, letting it drip down. I'm actually more concerned with a flush bottom panel than this technique. With the overlapping style at the bow, this works best with three or four panels per side. The lowest panel should be the widest, the highest one the most narrow.

Now as to cutting the bevel for the garboard. Cutting a rabbet takes a machine or plenty of hand and eye la-bor. So this is what I have done. I use heavy wood for the keel instead of a keelson, but I don't rabbet it. I bevel the bottom surface.

The way I do this is to draw an arched line on the side of a 2 x 4 with a batten and then use a straight edge to bevel from the line to a straight line 1 inch in from the edge, gradually as the angle changes.

This is not to scale, I've enlarged to show you how I did it. This can be done with 1 x 4, it's just that there's less space in which to land a plank. If you use a metal fastener it will have to be inserted vertically, regardless of the angle of the plank, otherwise a tiny split might emerge from underneath the plank. The one limitation of this technique is that it works best with a double ender, in the Ian Oughtred manner. In some boats the keel width will narrow, so that the straight line on the bottom of the keel will curve in at the bow and stern, alt-hough not very much, maybe less than an inch.

Keep in mind that what looks like a big mistake in the garage isn't always noticeable when your great ship is in the water and cruising out. Gaps disappear in the presence of glue or paint, and if a plank isn't perfectly fair down to the last centimeter, remember Francis Herreshoff accidentally bent a waterline in for Araminta. And when your boat moves through the water, the ripples will sound like applause.

Finally, I use plywood cut in the shape of a boomerang with the angle inside to bevel. For instance, if the an-gle I want to bevel into a stem is 25 degrees on each side of the stem, I cut from 3/8" plywood a shape I can hold to sand the bevel like this--

With sandpaper on the inside, I slide it back and forth until I've got the right angle. I've used these boomer-angs on bows, stern transoms, chines, and to round off the bottom of frames to take a rocker. I stiffen the out-side with a 7/8 x 1 1/8 piece, glued, which serves as a handle, too.



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