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By Rob Rohde-Szudy - Madison, Wisconsin - USA



Do you have… Edge Tool Envy? - Pt 1

To Part Two

To Part Three

Among the Instant Boat crowd, there seems to be a feeling that edge tool use is reserved for taciturn bearded dudes from Maine. You know…them reeeeeeal “craftsmen”. The rest of us must content ourselves with substituting the screaming noise and choking dust of power tools, even when a sharp hand tool is better suited to the job.

I don’t think we can afford for these edge tool skills to fade into oblivion. A little edge tool skill can go a long way in opening up the mysteries of traditional woodworking. Best of all, it makes you better at using the power tools because you think more about what is really happening. After all, even power tools are a bunch of little edge tools moving really fast.

But how to get started?

A couple of tools

I’m going to buck tradition here. Everyone seems to start off talking about planes, since they are the darlings of the traditional wooden boat crowd. But planes are complicated and we need to gain some more basic knowledge first. So let’s start with the two basic blades – the knife and the chisel. Since the plane is just a chisel with a jig, we can better understand what’s going on by figuring it out with the chisel.

These are also cheap. A decent hardware store can furnish a passable chisel for under $10. Get a narrow blade for now. Maybe 3/8” to 1/2”. You probably have one already, but get a sharp one. For the knife, a common utility knife and some blades will do for now. You probably already have one of those too.

Safety

I shouldn’t need to say this, but I guess I do since I still manage to cut myself. Think before every cut. What will get cut if you slip? Eventually, you will slip. Gloves don’t help with really sharp tools, so treat these things like the weapons they can easily be. Above all, clamp the work firmly and use both hands on the tool! No, actually above all, don’t try to do this stuff when you’re tired. That’s when I always end up getting yelled at because my wife thought I should get stitches. Now don’t blame me when you’re bleeding and cursing. Enough said.

Cutting technique

The first step is to get a bit of feel for how these edge tools work. Without some appreciation for their capabilities, it is hard to imagine someone going to the trouble of learning to properly sharpen them.

So find some scrap wood. Let’s use softwood for now. I used a 1x4.

First, strike a line on your scrap wood and saw close to it. Use a handsaw or jigsaw so you have saw marks to remove. Don’t obliterate the line, though.

Now let’s try to smooth this edge down to the line. This will probably be easiest by making “paring” cuts across the grain. Cutting with the grain, the blade tries to follow the grain rather than where you want it to go. This is why there’s less tearout when planing diagonally.

If you try cutting with the grain, you’ll probably find that one direction cuts OK, and the other direction pulls the blade down into the wood. This would be tearout with a plane, and can be a deep gouge with a chisel. Avoid cutting in that direction. You might find yourself sliding one forefinger of your fingers along the surface of the wood to help maintain the correct cutting angle. Take note of this, because you have just turned your hands into a kind of plane! The main difference is that the alignment is not so rigid with your hands, so you will probably take shorter strokes. (We’ll get to the other differences in another article.) If the wood is wide, you’ll probably cut to the line first on the side where the line is drawn, then finish the smoothing with the aid of a square.

Cutting a Rabbet

Use a soup can as a stencil and trace a concave curve onto the wide surface of your scrap. Now mark a line at half the thickness of your scrap. We’re going to cut along the curved line, down to half the thickness. Most folks would be reaching for the router about now, but that’s only easier when it’s a uniform depth. If that bottom surface were slanted it would probably be easier by hand. If you can’t do it by hand, you’re stuck building jigs to make a router do it, which is probably a waste of time for a one-off part.

Curved lines

Note that an adjustable combination square can be used as a depth gauge for marking this.

Depth gauge

First use the knife to cut lightly along all the lines to avoid grain tearout. This shouldn’t be necessary if you never make mistakes but…well…we do. Then we’ll cut a little deeper on the “depth line”, which allows us to cut/split out the first slice of wood. Actually, we want to stay a little above the depth line, since it’s easier to take more wood off than add it.

Now with the chisel we’ll make a shallow cut along the curved line, then “scoop” to continue the cut across and remove waste.

Again, one direction will tend to make the blade follow the grain and dive, and in the other direction it will cut well. I like to make a notch on the diving side. That way if the cut coming from the opposite direction turns into a split, it can’t split all the way into the stock I want to keep.

Anti-split notch

We repeat this process until our cavity is rough cut.

Cavity rough cut

For final shaping we can measure our depth by running a straightedge across the top and measuring down. I find it most convenient to use a barbecue skewer and mark where it intersects the straightedge, then measure. A tape measure isn’t terribly accurate for direct measuring this kind of thing.

Paring cuts with the chisel are the easiest way to finish to the line.

Paring bottom cut

Congratulations! With what you’ve just done you can make this fancy(ish) banjo neck joint. The whole neck was made exactly this way, with only the addition of a bandsaw and a spokeshave, which is comparatively easy to use.

Banjo neck

Yeah, I know it’s not part of a boat, but it gives you an idea what you can do with a sharp chisel when you put your mind to it.

Rolling bevel

Now let’s add something a little more boat-like. At one end of a 1x4, mark the top edge 1” in from the edge. At the other end, mark the top 1/8” in from the edge. Now flip it over. Mark each end 1/8” from that same edge. Connect these marks with a straightedge. You should have a parallel line on one side and a crooked line on the other. We’re going to create a flat plane between them.

Bevel marked

First we’re going to chisel some “notches” down to the correct plane. Begin by using the knife to cut through the outer grain. This keeps from splitting out the grain. In fact, it is not bad to saw down close to the final line.

Outer grain cut

Then we “pare” across the grain with the chisel. Leave about 1/16” of wood outside the lines. We’ll trim that last bit a little later. Don’t try to cut straight toward the line on the other side. Instead leave a lump of wood to be removed. With the line established on both sides, it’s not hard to pare off the lump in between. Here are the finished notches.

Notches

Once you’ve done this at both ends and at several points between, you can start “planing” down to the pared notches. Don’t try to use the utility knife like a drawknife. It is a poorly controlled cut and likely to slip and cut you. Both hands should always control the cut. Most of the time I find that the right hand is positioning the knife, and the left is resting on the work with its thumb propelling the blade. There the back of the blade meets the left thumb helps control cutting angle. This makes for short cuts, but that’s OK.

Waste lump

Here is a view of the work with part of the waste cut away. You can see that the next section is cut to (near) the line on both sides and the “lump” in the middle is waste. It is easy to cut this out accurately. The shaving should come from the middle. When it just barely touches both edges at once, your cut is level. (I had to crank up the contrast on that photo to let you see the lump.)

Lump shaving

When the notches disappear, sight the surface to see that it’s in plane.

Bevel planed rough
Bevel planed rough 2

The last 1/16” of wood is used to get it smooth and in plane. This is best done with a plane, but we’re well within range for sandpaper. For that matter we’re well within range for epoxy. Here it is smoothed a bit.

Bevel planed smooth

Congratulations, you’re ready for traditional lapstrake, if you have the time. You just cut the “rolling bevel” that so mystifies the instant boat crowd. Curves are the only difference between our rolling bevel and those on boats. We used a straightedge where a batten would be used in boat work.

Your tools are probably starting to get dull now. Next time we’ll look at sharpening.

Rob Rohde-Szudy
Madison, Wisconsin, USA
robrohdeszudy@yahoo.com

Click Here for a List of Articles and Columns by Rob Rohde-Szudy

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