Wood choices for Japanese bo

[Eric Schubert]

Hey, everyone! I have an interesting question that I'm, hopefully, posting in the correct place.

My karate class has been discussing the use of the traditional and primitive weapon called a bo. It's essentially just a long stick that's approximately 1" in diameter and 72" long (thickness and height can vary, give or take, depending on your height/size). The discussion turned to types of wood that might be useful for a bo, and so I thought I would pick the collective SMC brain for some ideas.

Some desirable properties would be:

Durability... this one's obvious. We'll be training with them and they'll take some abuse from hitting a training partner's bo, or perhaps another object. They need to be strong. I'm guessing some flexibility or shock-absorbing qualities would be very useful in creating a durable bo.
Weight: A bo should have some heft to it. You want a solid strike to hurt, not just bounce off an assailant. No balsa wood here!
Shape: A bo is round, so the chosen wood should be easily turned to the proper size. Not sure how much of a difference there is in this category, as I'm not a turner. But I'm guessing there's some variability.


There may be other properties that are important, but those are the ones that I could come up with.

My first ideas include:

Red or white oak. This is the most-traditional choice for a Japanese bo. Should be quite durable. Available, and probably fairly inexpensive.
Lignum vitae. Extremely hard. I assume it's also very durable..?
Purpleheart. Gorgeous. Fairly hard. Did I mention gorgeous..?


Any other suggestions or alternatives would be great! What types of wood do you think would work best for this type of application? As long as the wood is available, I'm not terribly concerned about price, as our sensei might be interested in something more-unique for himself.

[Andrew Hughes]

Nothing like a good piece of Hickory.Thats my vote!

[Maria Alvarado]

How about hickory?

[Maria Alvarado]

oops, you got to it first!

[Eric Schubert]

Thanks, Maria and Andrew! I'll add hickory to my list of possibilities. Any other ideas out there?

[Sam Murdoch]

I propose ASH as it is more flexible than hickory - will take a bit of "spring loading" and so provide a nice extra kick (theoretically at least, in my little head - or is that to my little head :D). In any case ASH is strong and straight grained and would look nice too. Lignum Vitae is a beauty but will certainly fall into the pricey category.

[rudy de haas]

I recently asked a friend with a lathe to make one as a presentation gift for a senior sensei moving to another city. It is a laminate made with real hickory (i.e. not pecan) on the outside and a thin strip of walnut in the center to add color, cohesion, and some compresibility. As it turned out his lathe isn't long enough so he hand carved (!) much of it, but it ended up near enough to right.

Two things to bear in mind:

1 - the standard bo lengths in imperial units work out to things like 72", but the original equiv for that would actually have been a bit more - say 73.25".so make yours a bit longer than the commercial ones that otherwise look right for you.

2 - the commercial (and/or competition) bo is typically fully round, and only marginally thicker toward the center with continuous tapering toward the ends.. The originals, however, tended to have somewhat more tapering on each end, and a 18 -24" or so piece in the middle that was both thicker (1.25-1.4") and of consistent thickness. (i.e. tapering starts about 10" off the center).

[Brian Holcombe]

Doubtful that you would even be able to find lignum vitae in that size range......and if you do please send to me so that I can buy out the stock :)

White oak or ash would probably be best. I'd stick to what's traditional, the Japanese are very good about choosing carefully.

[Eric Schubert]

Great ideas, everyone, thank you! Definitely leaning toward hickory, now. But, I'd love a bo made of purpleheart, too. Love that color!

I took a photo of a hardness chart for woods at a lumber yard. I'm seeing plenty of other hard woods, but I don't know enough about them to decide if they'd work for a long weapon that will sustain impacts, like a bo. Are there others near the top of the hardness list that might work?

For reference, here's the chart:
http://i163.photobucket.com/albums/t314/Mr_Spiffy/Woodshop/wood%20hardness_zpsacslhusw.jpg

[Justin Ludwig]

I'd use one of these three locally available woods: Hickory/Pecan, Black Locust, or Osage Orange (maclura pomifera).

I'm about to hand craft another walking stick out of some Osage I just got outta the shed. Cool thing about it, your grand children's grand children can still use it if no one loses it.

[ian maybury]

Be careful about hardness - it doesn't necessarily imply stiffness (but there's probably a decent correlation) and definitely not toughness/ability to withstand shock/absorb lots of energy without shattering. Technically toughness is the energy required to cause separation - not the force. A brittle wood or material fails/separates almost instantly once a particular force/loading is reached - with the result that no more energy is absorbed. A tough material will absorb a lot of energy to bend (there's a test for impact bending), and even as it fails it will only progressively tear apart abosrbing lots more energy all the way.

I don't have good information (seems it's not tested that much for woods) but judging by the limited list in 'The Encyclopaedia of Wood' it's not by accident that hickory was so widely used for tool handles - it's listed at more or less double the toughness of most other US hardwoods. The 'rest' (most oak, maple etc) tend to be grouped pretty closely together. Moisture content can be a significant influence too. Don't know, but it could be it's addressed in Hoadley's 'Understanding Wood'.

Chances are that most of these physical poperties (and probably internal damping/vibration absorbtion) would have quite a influence on the 'feel' of the item in use too. Perhaps there's a traditional wood used for them, and for a reason....

[Michael Kaplan]

I've made and own a couple of bokken out of domestic hickory- not quite as heavy as the Japanese oak ones I've purchased, but they seem to splinter less as they age. Though the hickory ones are a few years younger than the oak, so it's not quite a fair comparison.

[rudy de haas]

umm?

two things:

First, teak isn't that hard so the chart shown above is wrong; and,

second, you need to consider weight. Make the thing out of ironwood and it won't be useful as anything beyond wall ornamenation.

[Wes Ramsey]

One thing I would consider is that the bo would be stronger riven, not turned. Whatever wood you choose, make sure the grain is good and straight so you can rive the wood to minimize cross-grain cuts. And splinters.

[Eric Schubert]

I just looked up properties of teak, and I'm really surprised it was placed that high up on the chart. Thanks for pointing that out, Rudy. It's definitely a hard wood, but not as hard as that chart shows.

As far as weight goes, I want it to have a bit of heft to it. A competition or fighting bo will be heavier to ensure a good, solid blow. Plus, it'll help develop the muscles used during training. So, I'm okay if it's a bit on the heavy side. If I then pick up a lighter bo, it'll be a lot easier to use.

Wes, I'm not sure we'll have the option of riving the wood to the size we want. After some research, I understand the advantage of doing so, but it seems it would be hard to rive such a long and narrow piece of wood into a straight piece. I had considered making my own bo, but I have no experience with riving wood. And to get it round by hand (I don't have much for a workspace, yet), I'd still have to plane and sand it into a fairly round shape, which opens up some end grain along the length of the bo anywway.

Ian, when I was looking for woods that would be suitable, I used The Wood Database as a reference. One property that looked pertinent is the Modulus of Rupture, which shows strength of a particular wood as it's being flexed. This seems like it would apply fairly well to making a bo. I also compared the Janka Hardness values. I ended up looking for the highest values in both categories to find something both hard and strong as it flexes. Hopefully that was a logical way to choose a wood type?

[Kyle Iwamoto]

Rattan is what they were made of long ago. Light and very strong. Didn't see it on the chart for strength, I don't know how it would compare to say, oak or hickory. Flexibility is also a very important consideration. A bo needs to also flex.

[Andrew Hughes]

I was thinking the same thing about the Teak.I don't get to use it very often because it's so expensive.The pieces I have now in my shop are not harder than the hickory I have been Useing this year.
My small pieces of teak I have came from the area that was wiped out by the Tsunami.I have heard that Teak used to be very hard and not many woodworker have seen the old growth stuff.
Then there's always the chance some other species of wood has been called teak,Afrormosia come to mind.
We call cypress cedar so who knows what's whats anymore?

[Eric Schubert]

Andrew, I certainly agree. Common names can be very confusing. Someone had suggested ironwood, but when I looked that up I found that ironwood could be any one of a couple dozen species of tree.

EDIT: Also, just for full disclosure... I'm a total noob when it comes to choosing wood. I know a little about the most-common species, like oak, walnut, or maple, but I haven't really gotten in deep with studying the various species available for woodworking. Hence why I'm looking for advice on choosing a wood for my bo.

I believe rattan was a common choice, along with bamboo, for Chinese martial artists when making a bo. Certainly not a bad choice. Not sure if the lumberyard has it, though. I'd have to check.

[ian maybury]

Don't know if you guys get it, but there's bamboo flooring boards about which get sold for use in bathrooms and the like. Which may suggest that somebody is processing pretty hefty chunks of the stuff - which means it might be comemrcially available from the right timber merchant.

It might be tempting to glue of floor planks into a baulk, but i'd be very cautious based on personal poor experience making canoe paddles. (not bamboo) It's probably possible done right, but it's also possible to run into problem with premature breakage adjacent to glue lines. Maybe they cause a stress concentration or something...

[Rich Enders]

I'm going with Sam and Ash (Even if a woodchick can chuck wood). It seems to me that Ash baseball bats should be a good example of what you need.

[Brian Kent]

Most of the woods mentioned - White oak, red oak, ash, and hickory - are found on them from commercial sources.

I would narrow it down to my favorite 3 or 4 woods, and then spend a LONG time at your hardwood store to find one with the straightest grain possible, with the grain extending the length of the board. Next I would cut it to the desired dimensions and run it on a router table with a big Whiteside roundover bit. Then use sanding or scraping cards to get the grip you want.

I would use a Whiteside bit because my Whiteside bits do not burn the wood. I just used a brand new Rockler bit for simple rabbeting and had burn marks all the way around, even though I cut in several passes.

[Dipan Patel]

In my youth, we used to mess around with stick-fighting with short sticks, much shorter than you are talking about. These were made with Cocobolo commonly. It was tough and had a nice weight to it.

[John Gornall]

Grandson is 12 year old brown belt. At his age there is not a lot of contact but some of the older kids used his bo and it held up well. Made from hard maple. Too long for my lathe but I pushed it against a live center holding the end in one hand while sanding with the other. Center section has parallel sides and the end sections are tapered slightly - ends rounded. I ebonized it with an indian ink/shellac mix. He's grown and wants a longer one now. Considering adding red ends to the first bo for non contact cata and making another full length again in hard maple.

[Eric Schubert]

I checked around with local lumber yards, and it sounds like the only round stock available is oak (1-1/4") or maple (1-1/2"). I think for the sake of having a solid bo to start my training, I'll purchase oak, for now. But I have some 2"x2" stock that's somewhat short. I plan to see how difficult it will be to make it round using only hand tools (planes, spokeshave, sanding, etc.), as I do not have sufficient power tools to shape the wood. It'll be a bit more "rustic", but will certainly provide some satisfaction, if I can do it properly. But I can imagine some challenges with work-holding as it begins to take shape. (Especially with my primitive "bench"...)

My biggest concern with starting from rectangular stock is cutting a piece to a good size without internal stresses causing the board to curve as it is cut. Brian, I'll certainly take your advice and look hard to find the straightest grain possible to avoid that situation, should I try making one by hand.

Thanks again to everyone for the suggestions! If I decide to make one from scratch I'll post some photos of the process. :D

[Eric Schubert]

Last night I tested my abilities to convert a piece of wood into a round shape using only hand tools. The piece was approximately 2"x2" and nearly 2 feet long. I had laminated a pair of pieces together, I think they were pine of some sort.

I used only hand planes to accomplish this task. I started by thicknessing the stock, then planing it to width. Once the cross-section was approximately 1.25" x 1.25", I started planing down the corners to make an octagonal shape. All of this was pretty simple, but required frequent checking of the dimensions to ensure thickness stayed fairly uniform. Once I had all 8 sides to approximately the same dimension, I planed the 8 corners of the octagonal shape down a bit to get closer to round and sanded to a final finish.

It's obviously not perfectly round. But, I really like feeling the ridges and contours made by the plane. It gives me a better grip on it and it gives it some character.

Final conclusions: It's not nearly as difficult as I had expected, but this was only over a 2-foot length. Just keep checking the thickness with calipers, and also avoid creating dips and curves by checking with a straight edge. It'll be time-consuming, but it's totally doable.

[Sam Murdoch]

I hand shaped a 22' tapered flag pole once upon a time - made a lovely pile of curls.
I encourage you to get into the quiet and have a happy session making your handmade bo - allow the chi to flow :D.
You will become one with your bo Grasshopper.

[Eric Schubert]

LOL! Sam, I love it! Now, I just have to make a bo! Looking through wood choices, my main two options are hickory or jatoba. (really leaning toward jatoba...) Just making my short stick made a decent pile of shavings. I can't possibly imagine how large of a pile your 22' flag pole brought about! Probably more like a mountain of shavings.

While doing some research, I ran across someone's personal site (http://arakiryu.org/wp/?page_id=544) that describes all sorts of information about various woods and their uses in weapons. Looks like he's had quite a bit of experience with some of them.

[Curt Harms]

One thing I would consider is that the bo would be stronger riven, not turned. Whatever wood you choose, make sure the grain is good and straight so you can rive the wood to minimize cross-grain cuts. And splinters.

That was my thought. Windsor chair makers seem to prefer riven because it's stronger than sawn in small round cross sections regardless of species.

[Susumu Mori]

Hi Eric,

I don't know anything about bo but google search in Japanese sites say, "Kashiwa" and "Kashi" are the materials. There seem no identical trees in US, but the formal name of "Kashiwa" is "Quercus dentata" andthe latter also is a family of Quercus. The closest thing in English seem "Japanese Emperor Oak" for "Kashiwa" and "Japanese Oak", "Stone Oak", and "Live Oak" for "Kashi", but they are different from what we call "Oak" in US. Kashi is broad leaf ever green. In any case, they may not be very far from Oak. By the way, I believe Kashi is widely used for Japanese chisels.

[Eric Schubert]

Susumu, thank you for pointing that out. That's definitely not the same oak as what we have here in the US, and I'm not even sure if it's a related species. I'm guessing kashi has very different properties from red/white oak.

If I decide to make a bo by hand, I'll likely start with hickory, as it's readily available and a suitable material.

[John Gornall]

Of interest: http://kingfisherwoodworks.com/

I sometimes pick up a board at the lumberyard out of interest to take home and play. Recently I got a piece of Kashi and had not thought of using it for a Bo. Looks like a hard to work wood - I'll give it a try.

[Eric Schubert]

I did run across Kingfisher Woodworks. Unfortunately, they do not make a bo long enough for combat/training. (They're also pretty expensive.) But they look like their products are of high quality.

If you do make a bo from your piece of Kashi, I'd be curious how it turns out and what you think of how it handles.

[Bob Hoffmann]

I made mine out of hickory ... great weight without being too heavy. I started with a square piece that was as straight grain that I could find, then used a round over bit in a table router to get the piece rounded. From that I used a spokeshave to get it rond and tapered to the ends.

I also made one out of mahogany, laminated from several thinner pieces --- lighter and shows the dents a lot easier than the hickory does. Mine are both around 5' in length -- the smaller of the bo styles -- and easier to handle. For a finish, I used salad bowl oil ... stay away from a finish that seals the wood -- that will cause the bo to slip in your hands as you sweat ... an oil finish does not.

If you want to use a heavy one to work on strength, one in my dojo has a stainless steel rod that he uses (slow motion because of its weight) for working on strength. You really do not want a flexible bo unless that is the ones used in your style -- having one that flexes will use different strikes and handling than one that is still. I have seen ones that were longer that the 72" that had a lot of flex -- gives you lot of reach, but also harder to swing around -- and you need a lot more room height and space between the guy next to you -- for his and your protection.

Just some thoughts ...

[John K Jordan]

I don't think you can rely on a single chart.

Different trees of the same species, perhaps grown in different conditions and/or in different places, may have different properties such as weight, hardness, and strength. This is also true of even different parts of the same tree. For example years of slow growth in drier conditions may may make tighter grained and harder wood. Heartwood may be harder than sapwood. I have some 100+ year old walnut that is FAR harder than any other walnut I've ever worked with.

The numbers and rankings you see may vary depending on who made the list and what pieces they found to test or from where they copied the data. I've seen widely differing numbers in lists and experienced harder and softer pieces of the same species, sometimes in the same chunk of wood. And in any list of properties some are very close and could be functionally equivalent for your use.

JKJ

[Frederick Skelly]

One more vote for Hickory, then a second choice of Ash. I have a Hickory walking stick I cut live and let dry a few years ago. It's hefty and strong. Ash, as someone noted is baseball bat material - can't go wrong there.

Susumo Mori's post made me think of Live Oak. I was reading about it recently and it might be worth a look.

Fred