processing boo?

[MtDent]

So there's this pond in my neighborhood. Somebody thought it would be a good idea to plant some bamboo around it, and wouldn't ya know, its taken a good hold. There's definitely no shortage around here. My question is, how do I process this boo to get it flat and ready for backing? Most of this stuff is a good 4 or 5 inches in diameter, with at least 7 foot in length. Also, what glue do you guys prefer to use for this kind of thing? I know that's a stupid question because everyone is going to tell me its personal preference thanks in advance for your time.

[dmikeyj]

I have not prepared bamboo straight from the ground, so I can offer no advice on how proper drying is done.  But-
If you split the poles into 1/8ths, that will give you 1.5-2" wide pieces.  After its dry, you would flatten the inside however you want.  I prep bamboo slats with a sureform/hand plane, as the belt sander leaves undulations in the boo (If I had a 6 foot belt sander, it'd be no problem).
My guess would be to split it right away, then set aside to dry, not sure how long it'd take, but it should take alot less time than drying fresh cut staves.

Let me know how it goes, I have been thinking about making my own slats for a while now.  Am really interested in the splitting and drying success.

Mike

[DarkSoul]

This website seems to have a very solid list of tips and how-to's for drying bamboo. Looks like a well informed site. Also read this page.

I've got a few tips of my own I want to share with you:
- Dry the poles in the whole, and cut them to slats only after they've dried. I've heard of green bamboo slats 'curling up' as they dried, because the inside dried and shrinks faster than the outside.
- Cut poles as old and straight as possible. 4-5 inches diameter is perfect. One pole will easily yield enough material for six bows, so select the pole wisely as to not create too much loss. Old poles are a lot stronger than younger poles. It's hard to judge the age of a pole, but the harder and darker green, the older it is. Any brown leaves or bracts also indicate the pole is old.
- Do not over-dry the poles. When bamboo experiences rapid moisture loss, it will crack lengthwise. This can happen in one day, for instance when the temperature suddenly rises with a drop in humidity. Do that last bit of drying, to force out the last bit of moisture, after you've split/cut slats from the pole.
- Bamboo is an excellent backing for compression strong woods. Ash is not one of them; do not apply a bamboo backing to an ash board.
- Although is technically isn't, bamboo can be considered a wood. That means that any glue proven in wood-to-wood glueing applications in bows can be used. Titebond, Urac, resorcinol, G2 or other epoxies...

[MtDent]

Thanks a lot Dark! And Mike, I can post pictures of my adventures as I go and see if I can get any tips for you on what happens.

[Eric Krewson]

I have processed a bunch of raw bamboo.



Tried a lot of different ways, lost a lot of bamboo to cupping as it dried until I hit on a good drying method.

I cut my poles about 6' long, knock out the inner nodes with a hoe handle to get air flow through the poles(the nodes bust out really easily), seal the ends to reduce splitting(I use cheap super glue) and stack them in a corner for a couple of months. After a couple months of drying I pop a chalk line on them and run them through my band saw. I get inconsistent results with splitting.

I band saw most of the belly off the slats, and finish flattening them on my belt sander with a 36 grit belt. I have a jointer as well that speeds up the process a bit but do better work on my belt sander.

Here is the end result. I let the slats dry more before I use them on a bow and keep several in my drying box all the time in case the urge to make a BBO hits me.

[Badger]

  The way I flatten a slat is 3 basic steps that take about 15 min per slat. First I run over the belt sander just enough to knock off any bumbs that will interfere with my bandsaw guide. Then I run through a bandsaw inside edge facing guide. Lastly I finish flattening on my belt sander with 36 grit belt.

[Ian.]

When you finish the prep how much surface do you leave yourself with? The bamboo I can get from Garden centres tends to be pretty small and getting 1.25" flat surface is tricky, is there an easy-ish way to heat flatten it.

[MtDent]

Well I don't have a belt sander, band saw or anything like that... I have a circular saw (not effective for boo), a hand plane and a file.

[bushboy]

Having processed quite a few bb slats by hand tools only,my favorite tool is an old stainless ,half round file that I got from work,after removing the abrasive bits with a grinder ,lmaking a single bevel knife for lack of better words.clamp it down to a very stable work bench or table an start ripping at it.I also found that a bastard half round file does a good job of removing the node material to the desired depth.you can use the single bevel knife as a great scraper to get a uniform slat.be sure to wear good quality leather glove because bb will cut you to the bone!have found the that 3" bb will give 2 - 11/2" slats that not as likely to over power the belly of your bow.it's a lot of work but I've had good sucess using my method,regards bobbyjoe

[MtDent]

Well I do have a file. Very useful tool but I'll have to wait until this boo dries... its not as big as it has been in years past. How long should I let it dry for?

[Woodbender]

If you aren't into power tools, or don't want to pay for them, a toothing plane works very well for flattening bamboo. They aren't easy to find so mail order from a decent wood working catalog like Highland Woodworking Supply is your best bet. Buy the whole plane, or just the iron and make a body yourself. Dean Torges' video hunting the BBO is a great watch.

[MtDent]

How would I go about flattening this boo? And how long does it need to dry?

[DarkSoul]

I would highly recommend a belt sander for flattening bamboo. A cheap one costs only 30 dollars or so, and it will be usefull in other applications than flattening boo. If you insist on using hand tools, a drawknife will get you close. Then you can switch to a hand plane. Finish with a sanding block and 40 grit sandpaper.

We have already adviced you about the drying time. Eric, a very respectable bowyer, told you how long he puts his bamboo aside. The links I gave you on top also extensively comment on the drying process of bamboo. It dries equally fast as wood, so treat it like you're drying wood. How long does wood take to dry? We cannot give an inconclusive answer to that, that is not open for multiple interpretations. It depends on at least ten different factors.

[Eric Krewson]

Another thing; I live in N/W Alabama, hot summers and mild winters. My bamboo may dry quicker than in other parts of the country.

After your initial 2 month drying/stabilization period, you can cut out your slats, flatten them, cut and taper your final backing to shape to remove any excess material. Once thinned to 1/16" on all sides and kept in a dry place, your bamboo will be dry enough to use in a week or so.   

Here is an example of a bamboo pole drying without having the the nodes knocked out. The piece is too small in diameter to make any backing over an inch wide so I put it up in the dry as an experiment, nodes intact.

As you can see, it has dried in from the ends but the center section is still pretty green even after being cut for more than two years. I didn't seal the ends, they have developed multiple splits.

[bobnewboy]

When you finish the prep how much surface do you leave yourself with? The bamboo I can get from Garden centres tends to be pretty small and getting 1.25" flat surface is tricky, is there an easy-ish way to heat flatten it.

I have tried flattening bamboo with heat for the same reasons, but eventually I gave up as all I got was a lot of longitudinal splitting.  I bit the bullet and bought some which was far wider to start with. 

If you have a load of narrow bamboo already it might be possible, but rather time consuming, to follow Marc St Louis' recent article in PA where he made a bamboo slat from many edge-on bamboo pieces glued together.