Bow Build: Walnut Bamboo Longbow, Stage One

bow embryo
The two planks dominating the foreground comprise a bow in its embrionic form. You wouldn’t call them embrybows. But I would.

The darker piece is domestic walnut, black walnut. The lighter piece is bamboo. The walnut will be the belly, the bamboo the back. Bamboo makes good back.

Together, they’ll make a 68″ longbow or flatbow. Far as I know, unless you’re talking English longbow, flat and long are more or less swappable. As far as I know.

Now, let’s get to work on this thing.


The bow:
Type: Longbow or, more specifically, flatbow
Dimensions: 68″ long, 1.5″ wide
Materials: Domestic black walnut, bamboo
Handle Material: Yellowheart and zebrano (zebrawood)
String: Brownell Dacron B-50
Glues: Smooth On EA 40 and Titebond III

boo compareFirst I want to show you something about the bamboo piece. This bow will use the one on the left. See how it curves with nodes sticking up? All that needs to end up as flat as the guy on the right. On the left, the thinnest piece of bamboo in the order of ten planks. On the right, the thickest. The one on the right has almost no inside curve. Probably thick enough to pert near be a bow unto itself. That may be the plan, actually.

Anyway, your bamboo can come in different thicknesses. As long as you can sand it flat and still maintain the width you need, differences in thickness don’t matter — in my experience, which is limited to eight pieces of bamboo so far. I only feel experienced. However, from both my experience and advice of better bowyers, with bamboo, go thin. I’ve never broke the boo on a boo stick. But I’ve seen at least three bows ruined because the bellywood couldn’t stand up to the stout bamboo.

I ordered 10 boo planks from Frank’s Cane and Rush Supply in California. Eight feet long, two inches wide. Shipping cost more than the boo. How do I feel about that? I can hardly wait to place my next order with Frank’s. I’m not the only bowyer he sells to. He knows the score. He helped me save as much as I could. Each piece works out to about 8 bucks. One plank at my beloved 3Rivers is around 20 bucks, before shipping cost. You don’t even need to do the math.

boo tip compare
Compare the thickness of the one on the left and right. It’s even more dramatic than this photo depicts.

OK, so that’s the boo. Now for the walnut.

After I cut the the piece, I discovered this hidden gem:knot
Wormhole? Cigarette burn? Knot?

It’s actually not a problem (pun unavoidable). I hope. It’s above what I expect to be the top of the bow belly. In other words, that sucker’ll get shaved away along with all the surrounding wood at that level. You’ll get a better idea of that in a soon-to come pic.

The next step: cut the walnut to length. I zipped four inches off this 72″ piece. Its width is 1.5″ and it’s about 1 & 1/16th inch thick. Then I drew on it.

But not before I assessed its pristine straightness….

walnut crooked
Crooked as a dog’s hind leg.

Am I worried about this? Ha! I’m a bowyer. I never worry. The best way to approach bowmaking if you don’t know what you’re doing is to forge ahead and just figure the whole project will be a heartbreaking waste of time. That way, if you get an even half-decent bow, you’ll be thrilled.

But honestly, I’m not worried about this bend. It occurs along the back of the wood, which will be pressed flat on glue-up. If it were curved left to right, I’d toss it in the steamer for a few hours and straighten it. Like I’m going to have to do with the boo. More on that in a bit.

The next thing is: draw a center line.center line

This one is at the 34″ mark, because I’ve got a 68″ bow.

Then I draw lines to mark either end of my 6″ handle, so two lines on either side of and each three inches from center.handle lines
Note the precision with which I execute that center line.

I draw the lines around the bow, top, bottom, sides. And yeah, that center line doesn’t match up at the corner. The line on the side will be sanded off after the glue cook. So these lines are close enough for now. I’ll redraw if necessary.

Then I draw the lines for the fade, in this case, two and a half inches from either handle end.handle fade lines

So we have the center line, with the cross line marking the longitudinal center of the bow, the handle lines, and the fade lines. The fade is the part that slopes down from the handle to the limb. You’ll get a better picture of that later unless I screw up or forget.

Next I draw the limb line.limb line knot gooder

Not that you can see it all that well in this pic. But here’s the idea: at the fade, I marked a line a half inch up from the back of the walnut plank. At the other end of the plank, I marked roughly a quarter inch and a squidge. Then I take a metal yard stick and I draw a line from the mark at the fade the to mark at the end of the bow. What I end up with is a taper from about a half inch to a quarter inch (and a squidge!). And real important: I will cut away wood above that line. I try to make the limbs a bit thicker than I think I’ll need them. It’s easier to remove wood than put it back on.

If you didn’t follow that, don’t sweat it. It’s because it’s hard to describe this stuff. But I’ll show you later what I mean. Well, try to.

OK, now that the walnut is lined up, so to speak, I have some work to do on the bamboo.

First, I have to trim its 8-foot self to 68″. So, just knack off a couple feet and change, right?

Nope.

According to Sam Harper of Poor Folk Bows, you want the nodes on either end of the bow to be the same length from the tips. What?

Here’s one end of the boo plank. The line denotes where I’ll trim.boo trim right

Note the proximity of the line to the node. Now check out the other end.boo trim left

The line is about-ish the same distance from the node on this end. According to Sam, you want the first nodes at the end of the bow to be the same distance from the tips. Why do I feel like I’m making less sense than I want to? Well, again, I plan to illustrate that better with other pics. But why does this node distance matter?

Answer: I have no stinking clue whatsoever. I’m taking Sam at his well established word. But someday I’m either going to ask or try cutting the boo so one node is about at the end of one limb and at the other end, the node will be maybe 6 inches from the end. Just to see what could possibly go wrong.

Anyway, now that I’ve trimmed the ends, I need to flatten the boo. I do that on my beloved bench sander.boo unflat
This is what the boo looks like prior to flattening.

boo flat long
This is post-sander. Flat as a road-killed toad.

boo flattened
Close-up of flattened boo.

boo dust 2Not an early snowfall in the 4B. That’s bamboo sawdust. Well, sander dust. This photo shows the amount I did not inhale during the flattening process.

boo dust 1I had this other boo dust photo. I thought, why let it go to waste?

Important: The boo will be trimmed and sanded again once I get it lined up with the walnut plank. But that’s going to take some steaming and straightening. Here’s the boo showing off it’s plumbline figure:crooked booSee how it starts out curvy and gets worse?

The boo plank is about 2″ wide. The walnut, 1.5″. Once I straighten the boo, I’ll lay the walnut on it, align them both to center, then mark and trim the excess boo on the bandsaw.boo too wideWe’ve got about a quarter inch more boo than we need on either side of the walnut.boo trim linesAll steamed up and straightened. The walnut plank is clamped to the boo plank, it’s a simple matter of drawing the trim lines. I trim close to the lines with a bandsaw and finish up with the bench sander, which I love.

NOTE: Frankly, this is the first time I steamed the boo to straighten it. With all my other boo bows, I straightened the boo during glue-up. Kind of muscled it into place and clamped it. Worked fine.

So why did I steam this one? Because I can. With my new steamer, I needed to see how much better the boo would behave after a nuclear sauna. Not that much better actually.

Would I steam again or skip that step?boo steamer burn

See that dark spot? That’s steamer burn. Coat hanger wire inside the steamer holds the wood off the hull of the steamer tube. The wire got hot enough to singe the boo.

So, yeah, I’d steam again … if I wanted the burn effect, which with this bow I sorta like. Maybe. The steam job also drew a reddish brown tint in parts of the boo. I like that too. Character.

But for other than those aesthetic considerations, no, I probably would not steam if I didn’t think I needed to. Once I’ve thinned the boo to the point where it’s ready for glue up, it’s easy to straighten it on the form. Your results may differ.

Now we move to the glue-up, the cook, the trim, tillering and further agony. And that’s all in Part II

3 thoughts on “Bow Build: Walnut Bamboo Longbow, Stage One

  1. Pingback: Bow Build: Walnut Bamboo Longbow, Glue Up | BrokeStick

  2. Pingback: how to make a walnut bamboo longbow

  3. Pingback: longbow flatbow walnut bamboo build

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