Primitive Archer
Main Discussion Area => Bows => Topic started by: cool_98_555 on July 05, 2018, 09:07:59 pm
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I have a few long raw strips of moso bamboo, but they are curved and i need to flatten them to put them on bows. I don’t have a planer or a large belt sander, but i do have a table saw. However, using a table saw to flatten bamboo freaks me out. Seems too dangerous to me. Any ideas? What do youguys do?
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The best account of how to flatten bamboo comes from the late Dean Torges DVD Hunting the Bamboo Backed Bow. He used a jointer to rough it flat, then continued with a sharp block plane. There are a lot of subtle details that will help you avoid mistakes, and safety issues, but it would take too long to tell you, so I recommend buying a copy of the dvd.
As the saying goes "There is more than one way to skin a cat". A budget method would be to buy or borrow an electric handplane with TCT blades and rough it flat with that. TCT blades are very important as bamboo has a lot of abrasive silica that will quickly blunt your blades. You could use files or rasps, or spokeshave, or block plane, to bring it to its final shape and size. You also need to make a template for your backing or you will end up with uneven edges, too much thickness of the boo.
Like I said you could make a bow without seeing the dvd, but you are likely to waste more time and money with mistakes.
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I used a hand plane for my first one. When it starts to get thin put some shims between the nodes to stop it from flexing too much. You can also buy a 36 grit belt, cut it open and glue it to a piece of 2x4 with double sided tape. Clamp the boo to a bench and wear yourself out ;D ;D
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Japanese plane it down after splitting it into strips. Once it is more or less flat, what the other guy said. Get a block of wood, staple 40 grit sandpaper to it and get to work sanding. Not fun, but does the trick. A cabinet scraper is good toward the end to see if it is nice and flat.
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One of the nice things about getting it down to 1/8" or so is that the tube strips will bend it so it can conform to the bow. As long as you've got it smooth it doesn't have to be pool table flat to get a good glue joint.
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Power tools are a waste of time!
A good sharp plane takes it down very nicely.
If you clamp it to a length of 2x2 just if front of a node, that stops the plane pulling it away from the clamp. If you rasp a slight flat on the nodes it helps it stay clamped relatively flat.
A couple of pointers here.
https://bowyersdiary.blogspot.com/2014/11/bamboo-backing-build-along.html (https://bowyersdiary.blogspot.com/2014/11/bamboo-backing-build-along.html)
Del
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Well, I can take bamboo from thick to the finish taper ready to glue to the core on my belt sander with a 36 grit belt in around 10 minutes or less, time well spent.
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You can clamp it to a narrow chunk of wood and do bulk removal with a coarse rasp. Just be careful to not rip splinters off the opposite side as you work.
You work a stave to a flat belly this way so there's no need to think it's much different.
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Thanks for the replies guys. Ill have to try a few of these things you mentioned. Ive got quite a few thin strips of purpleheart and bloodwood that i want to use in the core as a quad lam, so if i can make this bamboo do what i want, I don’t have to buy the pre-planed stuff.
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Quad lam? Not that it couldn't work, but man that's a lot of gluing. I use about 5 ounces of glue on a tri lam.
10 minutes Eric!... I'm doing something wrong. I'm sending you a PM.
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Ive done it before 😃
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I went out an looked at my bamboo stash and realized I had my sequence off a little; It is bandsaw the edge at an angle to get rid of the bulk of the belly. I use the rind as a guide and cut at a slant down one edge then the other, I don't attempt to do a vertical cut as it is too risky. Next it is the jointer almost to a knife edge, then a trip to the belt sander to get rid of any chatter from the jointer, draw the pattern and cut it out and finish up on the belt sander. Except for the time spent drawing the pattern I would guess it is 15 minutes tops for all of the thinning. I do start with a 1 1/2 wide slat so I don't have much extra to fool with.
A sharp 36 grit blue zirconia belt will take off material at an alarming rate, including knuckles and finger tips, ask me how I know.
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I flatten the inside on the jointer so I can lay my pattern on there nicely, cut to front profile on bandsaw albeit a bit wide at the tips, a few more passes on the jointer or edge sander where it's obviously too thick, then always finish thinning with the toothing plane... the way, and for the reasons discussed in Dean's dvd. The glue joints are literally invisible and impossible to be starved of glue.
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I agree with Eric, I never spend more than 10 min prepping a piece of boo. I run it through my bandsaw at a slight angle following the edge on both sides and then sane with a 36 grit belt on the belt sander
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Get yourself a decent belt sander.
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They make a sanding disc for the table saw that probably would work I'm ordering one of these for doing precession scarf joints because of the large table surface for jigs ! https://www.woodcraft.com/products/woodriver-10-table-saw-sanding-disc-mounting-plate?gclid=EAIaIQobChMIj5WAgNKM3AIV3rrACh3hmgX_EAQYAyABEgI2r_D_BwE
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I can do it in 5 seconds with my light sabre.... takes longer with the heavy sabre ::)
Sorry... :-[
Del
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(lol) (lol) (lol) :OK -Funny Del !
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Which version of the light sabre is best for boo, original, or prequel.
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It is not really about speed, it is just that it doesn't take but a few minutes if you have a procedure and tools. I usually buy about a dozen strips at a time and process all of them at once. It doesn't take very long at all. If you don't use them right away you have to go back over them before using because they tend to arc toward the back after sitting for a few days or even less. This can cause cracks when you pull it down flat with the rubbers.
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Another thing I have found if you buy in trunk form or cut your own it is best to let it dry in trunk form until you plan to do the thinning. I cut a truckload one time and immediately cut it into slats but left it untrimmed or thinned. Every bit of it cupped into a U shape as it cured and was unusable. Any I cut green now I just knock out the internal nodes with a hoe handle and put it in the corner of my shop to dry.