Making a horsebow from wood & bamboo

[Ade-The-Blade]

Hi, I'm from the UK, and have just stumbled upon your site. I'm thinking of trying to make a Mongol type bow, but instead of the traditional method of horn/sinew (which I will tackle at a later date), I'm wondering whether or not it would be possible to make one from just wood & bamboo.

I know that the limbs would be under an enormous strain at a full 32 inch draw, and on such a small bow, traditional methods of bow building with wood, would not work. What I am thinking about is making the belly from several veneers of Ipe, and the back of the bow from several veneers of bamboo, and using hide glue to hold it all together. These veneers would be pressed together in a form/mould in much the same way as modern recurve limbs are made. Each veneer would be about 1mm thick. My thinking is that this would enable the bow to bend far enough, without breaking, whilst still retaining power.

Has anybody ever tried doing something like this before, and if so, what were the results?

If not, can anybody suggest any problems that they know of, that I may encounter.

I would like to try this, as an experiment, but if it's been done before, and not worked, I would like to know about it before wasting any time or money on the project.

Thanks in advance for your help, guys.

[DarkSoul]

Welcome to the forum! Now, since you've "stumbled upon us", you're hooked for life

Wood and bamboo simply cannot take the strain as experienced in sinew/horn composite bows. That means the design of the bow will need to be adjusted as to lower the strain on the back and belly, so these materials CAN take the strain. Make the limbs wider, bow longer, lower drawweight...or all of the above.
Just wondering...how many (laminated) bows have you made before?

[bubby]

Lukasz Nawalny on here has made some bows simillar from hickory and sinew, check out his posts and videos on youtube, Bub

[bubby]

i think robustus made an all wood and boo, might have been all boo that won BOM last year, Bub

[half eye]

bubby hit it on the head.....also consider the Mosquito, it out flew all metal planes easily and had not any stress related failures. Laminated wood done correctly will take a great deal of force. ( G force, and bending force )Being from the UK perhaps there are some of the woodworkers from the 30's/40's era who could really enlighten you. I know that Britain's glue was a very guarded secret as well. I would believe your project is doable.
rich

[mullet]

I would bet that James Parker, "Robustus" has done more research and has a ton of records doing just that with Boo and wood. He has compiled a lot of information on wood tapers to hit specific draw weight with different bow lengths. I own some of his short bamboo backed wood bows and they shoot fast and flat.

[Bryce]

I'm not sure that you can substitute sinew for bamboo and ipe for horn. The values of those materials cannot be matched. (Correct me if I'm wrong). Composite bows store an enormous amount of energy. I heard a story where the string had snapped while trying to brace the bow and whipped around and broke the man's arm.

You can make a bow with lams in the same shape. But its going to be longer and maybe wider. So it wouldn't end up being a short horse bow. It would be like a long 5 curve or something with a much lower draw weight.

[Pat B]

James Parker(Robustus) won BOM in April of 2009 with a bamboo backed and bamboo belly Turkish style bow with ipe/maple lam core and Spanish cedar siyahs.  This bow pulls 54"t/t, 60#@30". I've seen and shot this bow. It is an incredable piece of work. 
  You can read the BOM article in Aug/Sept 2009 , Vol 17 iss. 4 of PA Magazine. It may be in the BOM archives too.

[mikekeswick]

This sort of question always raises the same answers.
1 - No it isn't possible to directly copy a horn/wood/sinew composite with just wood.
2 - It is possible if you modify the dimensions. If you want it to be short then you need to make the limbs wider and thinner and spread the bending areas along the limbs.
Where in the uk are you? I'm in County Durham
The closely garded secret glue is resourcinol - absolutely amazing glue and i've talked to the guy who developed it. Some of you from over the pond should try it.

[Ade-The-Blade]

This sort of question always raises the same answers.
1 - No it isn't possible to directly copy a horn/wood/sinew composite with just wood.
2 - It is possible if you modify the dimensions. If you want it to be short then you need to make the limbs wider and thinner and spread the bending areas along the limbs.
Where in the uk are you? I'm in County Durham
The closely garded secret glue is resourcinol - absolutely amazing glue and i've talked to the guy who developed it. Some of you from over the pond should try it.

Hi, I'm from London, so a long way from County Durham.  I had already decided upon making the limbs wider and trying for the thinnest limbs that I could get away with, this is why I was thinking about 1mm veneers instead of standard laminations. I was hoping to end up with limbs of 8mm thickness with 7cm width, tapering to approximately 35mm at the point where it joins the Siyahs. My thinking was that the lamination of such thin veneers would allow the bow to flex by the required amount without breaking. I am familiar with resorcinol, but really wanted to try and use all natural materials, so hide glue seemed to be the best prospect.

This is really just meant to be an experimental project, as I like to think "outside of the box". I was thinking of making a small test limb first approximately 18 inches long by 3 inches wide, and seeing if the bending & compression qualities can be achieved first. I'm a great believer in research, planning, design & intensive testing, long before starting an actual project.

In reference to James Parkers bamboo bow, this was what got me thinking about the idea of trying for something new. The fact that he could make a horsebow from natural materials without using horn and sinew, shows what can be done when people think 'outside the box', and apply good engineering design principles.

My intention isn't to just copy a mongol bow, but to come up with something new, using that basic design as a sort of 'starting point', template. The Mongol bow really is an amazing design in itself, but does require the original materials to fully realise its full potential. I am not trying to surpass it, but merely looking at ways to try and produce something close to it, using more readily accessible materials, and using a less labour intensive method of production. The challenge as I see it, would be to do it using only natural materials.

[JW_Halverson]

The Flying Karamozov Brothers used to do this incredible juggling routine in which they would proceed in order thru 5 Disciplines of Juggling, each becoming more complex and difficult.  Once they had completed the Disciplines they would then explain that upon mastering your discipline (learned the rules) you were allowed to break the rules. This was called JAZZ!  At that point the show became sheer organized chaos as each of the 5 jugglers would begin improvising on the Disciplines. 

The same applies to music, engineering, and even relationships.  Until you know the limits of known Disciplines any experimentation is likely to be flawed fatally before you start.  Like in this case, you have some working knowledge of the bow design, and the limitations of the materials  But are your bowmaking skills (your Disciplines) up to the task?  If your woodworking skills are up to the task, and your glue-up experience is there, go for it.  If not, maybe shelve the idea and work your way up to it. 

Either way, I want to see pictures and reports on a regular basis!!!  Given your ambition, the bows you build should be very interesting. Welcome to the Forum!

[DarkSoul]

Limbs 7 cm wide? Wow, that is a lot. But it will certainly lower strain the limbs, which is a good thing for the design you're after. With limbs that wide, you would have to cover the back with several slats of bamboo. Probably three slats, because with two slats, you will not end up with a nice backing near the tips, where the limbs are much narrower. Preparing multiples bamboo slats for glueing them down, won't be easy, I guess.

The number (and thickness) of laminations does not determine how far a bow will bend. It's not as simple as "the more lams, the less likely it is to break". Thinner lams are easier to bend, and will keep their shape better once the glue has dried. But it has drawbacks, as prepping the lams is a lot more difficult, and fitting all lams together before the glue starts to set, might take a lot of effort. I would advice you to use several lams of 3 mm thickness. That's thin enough to create sharp curves in a bow, yet requires only a few lams. Requires less glue as well. Furthermore, clamping lams of 7 cm wide will be a real challenge. How will you be clamping the whole set? A form and airhose? Or.....?

Just wondering. What is your bowyery and laminating experience? Have you made any bows before? A laminated composite bow with nice glued in recurves is a really advanced project. Ambition is great, but don't get ahead of yourself.

[Ade-The-Blade]

 
Until you know the limits of known Disciplines any experimentation is likely to be flawed fatally before you start.

Either way, I want to see pictures and reports on a regular basis!!!  Given your ambition, the bows you build should be very interesting. Welcome to the Forum!

Hi,
    I agree with you wholeheartedly. Part of the reason for this particular experimentation, is to find out just how far those limits really are.

My woodworking and gluing/laminating skills are quite well honed (in terms of skilled joinery), but i'm not experienced in bow-making. I've studied up on the subject(over the past few years), and made test pieces to test out pliability, energy storage & breaking forces (I've made enough test pieces to make a dozen bows & learnt a lot from the process), but making a straight-forward bow does not excite me as much as tackling a more complex task.

I'm already aware of the difficulties of the task, and the likelihood of getting it wrong, but the aim of this exercise is to learn through experimentation, not necessarily to end up with a working bow. If I do succeed, then it is a bonus, but not necessarily the goal. It is the experimentation that holds the fascination for me.

Whether or not I actually make a bow of this design is entirely dependent upon the results of the testing phases. I've made simple working test limb sections from thicker laminates (tapered & non-tapered),which would be fine for regular longbow use, but for the extreme bending forces that a Mongol bow requires, these would not even be close to suitable.

If testing proves to be successful enough, then the actual bow project will be undertaken. If after exhaustive testing I still cannot attain the required results, then any lessons learnt can always be applied to a less ambitious project.

Sometimes the journey is more interesting than the destination.

Thanks for all the input & advice so far, I welcome as much input as possible as it is food for thought.

[Ade-The-Blade]

With limbs that wide, you would have to cover the back with several slats of bamboo. Probably three slats, because with two slats, you will not end up with a nice backing near the tips, where the limbs are much narrower. Preparing multiples bamboo slats for glueing them down, won't be easy, I guess.

The number (and thickness) of laminations does not determine how far a bow will bend. It's not as simple as "the more lams, the less likely it is to break". Thinner lams are easier to bend, and will keep their shape better once the glue has dried. But it has drawbacks, as prepping the lams is a lot more difficult, and fitting all lams together before the glue starts to set, might take a lot of effort. I would advice you to use several lams of 3 mm thickness. That's thin enough to create sharp curves in a bow, yet requires only a few lams. Requires less glue as well. Furthermore, clamping lams of 7 cm wide will be a real challenge. How will you be clamping the whole set? A form and airhose? Or.....?

The method I was intending for the bamboo, was to stagger the laminations (Imagine a cross section as looking like brickwork), with 3 on the top face, as you suggest.

I have a design in mind, for a temperature controlled trough, so that all the laminations can soak in the glue, and then be put straight into the form in one go. The trough & form would be specially made for the task (i've already worked out the designs).

I'll try the 3mm laminations, as it seems like a good idea.

As I've stated in another post, I've done a lot of testing, and have a lot more testing to do before making the final decision as to whether the project actually goes ahead. I tend to do loads of research & testing, as this approach has always worked in the past for just about everything I do.

Thanks for the input.

[Pat B]

Contact James. He is a very open guy that shares info. James does lots of research and expermentation with each of his bows and has always been generous sharing info with me. 
  James is Huntwortyproductions