Alright here is my first attempt at a blog. I will be building a wooden bow I will include pictures and step by step details as I go along.
Before I start I have to give credit where credit is due. Most of this info I learned from Dean Torges’s video “Hunting the bamboo-backed bow” I also learned a lot from the good folks at the “Leatherwall” traditional archery forum.
I highly recommend both sources if you want to make your own wooden bow.
First some materials.
I will be using Massaranduba for the bow (The reddish looking piece in the middle) It is sold locally as a 1×4 tongue and grove. This wood is a little oily and incredibly hard. 3190 on the Janka hardness scale (This test measures the force required to embed a .444-inch steel ball to half its diameter in wood.) I should also mention that this wood is one of those types of wood that may cause allergic reactions. Dust masks and dust collection are in order here. Also if you get a splinter you WILL know it by the next day (ouch).
I should be able to get 2 bows out of this piece. The bow will be backed with bamboo. This will help to keep the wood from breaking when we bend it. (some called it nature’s fiberglass)
On the left, sitting on some really nice ipe (for another bow project latter) is my pattern.
On the right is my piece of Bamboo just the way it comes when I order it. (not sold locally)
The first order of business is to prepare the bamboo. You will notice that I have evenly spaced lines on my pattern. This is to help align the nodes of the bamboo some what evenly on the bow. I line everything up to get me the best layout then mark the center and the ends of the bamboo. Then I cut it to length.
Next I need to flatten the back of the bamboo. For this I will use my brand new jointer! I just love this thing.
Here is what the bamboo looked like before and after I flattened it:
Now I need to trace the pattern onto the bamboo. I clamp everything down and use a string to ensure that everything is straight and that the pattern is centered on the “hump” of the bamboo.
I cut out the pattern with the band saw, staying to the outside of the line. I will use the belt sander to bring it to the line.
I use a belt sander to sand the edges smooth down to the line. As well as thin and flatten the bamboo to its final thickness. You can see here the difference before I thinned it and after. The bamboo needs to be thinned downed to about an 1/8” in the middle tapering to about 1/16” on the ends.
Now the bamboo is ready.
I ripped the 1×4 material in half so I could get 2 bows out of it. This is a little risky because there is just barely enough material and if the board bows significantly when cutting it I may not have enough material to keep the bow centered. So instead of 2 bows I get NONE! This piece has really straight grain so I am going to chance it.
Looks like it will work out fine. Very little curve
Just barely enough room! I need that 1/8” excess on each side otherwise the glue will “fall out” of the joint during glue up. You HAVE to leave some room around the joint for the glue to puddle up otherwise you will end up with an ugly glue line with holes in it.
After cutting to length, I tapered the massaranduba from the center (actually 6” out from the center) to the tips on the jointer. This will help the wood bend in the form and will be less material I will have to remove by hand later.
Time for glue up. Forgive me but I forgot to take some pictures during this process but basically here’s what went down:
I ran a toothing plane blade (actually it’s a regular plane blade that I ground “teeth” onto with my dremel tool) over both of the gluing surfaces. Then I mixed up some Urac 185 glue. This is a 2 part urea-formaldehyde glue. It works great for this application. After spreading the glue liberally on both surfaces I put the wood and bamboo on the form and clamped it down. In this case I am raising the ends to put some reflex in the bow, while trying to keep the handle section relatively flat.
You’ve heard it before: You can never have too many clamps!
You can’t quite see it but the glue squeeze out is puddling around the edges of the bamboo. This is critical for a good looking glue joint.
Well that’s all for now. This will have to sit for at least 24 hours before I take it off the form.