Making Horn and Sinew Prods?

First topic message reminder :

After having read about them I would really like to build one. I was wondering if anyone had any plans/ experience with making horn and sinew prods. About the only thing I know about them are that they are made from horn and sinew (Capt. Obvious strikes again )

If I can get the process down (and its not too time consuming) I may make a few more to sell for those looking for that extra touch of authenticity to their period crossbow.

Been browsing some old Primitive archer Magazines this evening and this is what I learned.
1 Try buffalo horn, cut in a spiral for long, stiff strips. needs to be heated gently and flattened, then cooled.
2 Ipe looks like a great core choice. Its high density gives more potential for storing energy.
3. deer leg sinew is a less desirable sinew. It has shorter fibers and is a little harder to work with. Back sinew is good stuff but some writers think it should be used for other things. Chose an expert with an opinion you like?

Swotavator,

That's a lot of questions! I am going to hit a couple of high points and make a few suggestions.

Have you got a copy of Holger Richter's "Die Horbogenarmbrust? It is really a "must have" even if you don't read German.

I am not familiar with the properties of ipe wood. As far as I can tell, when wood is used at all in crossbow prods it is oak. It is usually rather thin, and I get the impression that is it is there more as a "scaffold" for the construction than as a working component of the bow.

As 8F suggested, buffalo horn is thought to be the best horn for bows. On the other hand, cow horn is better than no horn.

I don't know why there is a layer of leather in that diagram.. I know of no other examples where leather appears in a sectioned, published prod. I would leave it out.

The traditional waterproofing material is birch bark. paper and Tite Bond III is a novel departure. It might work fine!

Have you made up full sized sketches of the prod in plan and elevation, along with cross sections at all the important points? I highly recommend full sized sketches for all projects. It's a cheep way to work out problems.

I hope you will keep us posted on this project!

Mac

As far as the recurve is concerned. I think that it would be better to think in terms of building it in rather than hoping that the shrinking of the sinew will do the trick. I think that these bows are just too thick to expect much recurve to result from shrinkage.

Indeed, I'm not at all sure that shrinkage induced recurve is what you want. In a thick mass of sinew, the tension on the outermost layer is very great when the bow is drawn. If the recurve is archived by shrinkage of subsequent layers, the lower layers will be partly in compression when the bow is unbraced. This would create a situation in which they could not contribute much when the bow is drawn. At the same time, the fibers at the extreme back of the bow may be stressed to failure.

It seems to me that in an ideal situation, the subsequent layers of sinew would be in progressively less tension in the unstrung condition. This would let all of the sinew fibers experience a more equal level of tension when the bow is drawn.

Mac

Thanks Mac!

Yes, i have sketched it multiple times. Ipe is an unbelievable wood. heavier than water, and very hard. I want to say almost as hard as horn, and it will serve as my nut as well as in the prod. It is very stiff, but also bends pretty far without breaking. It is traditionally used in laminate warbows, and i understand that it has similar properties as yew heartwood. It is also much better than oak in compression (which is what the belly needs to take) so if oak was used, i will be ok.

Since you say the wood is mostly a skeleton, I will have to scale back the ipe thickness. perhaps 3/8 tapering to 3/16. I intended on grooving it but i don't know if this will weaken its back. it might be better to glue the horns straight on. Maybe i will just roughen the surface.

That is a very good hint on the recurve. The idea of progressive layers of sinew taking different amounts of strain makes sense. I think i will glue in the recurve in steps. perhaps 1" at the horn, 2", 3" at different parts of the sinewing.

Already bought the cowhorn, so no going back on that. Though i thought i heard of people using that, historically. Also were there water buffalo in medieval france?

Wondering if I really need the rawhide wrapper. It is very thick. perhaps i can get away with a linen wrapping between the paper and sinew?

Progress is good. I am almost done with the roller nut (4.8cm by 3.6cm ipe with horn reinforced prongs), and have all the pieces of the stock (walnut, ipe, wenge, maple). The ipe is such a bitch to work, I had to make a macguyver lathe with a drill, rat tail file, and sand paper.

Hi Swotavator.

Let me share a couple of thoughts on your prod:

Ipe is an excellent bow wood. I do not, however, think it to be the best core wood; it is too heavy and can be difficult to glue. The best core woods are relatively light and glue well. Examples include maple and yew. I can find literature that confirms that yew was used as a core.

If you want to use Ipe, is the horn needed anyway? Sinew backed Ipe would make a formidible high weight prod.

As far as sinew goes, there is nothing wrong with deer leg sinew. It is my preference for my sinew backed hunting bows. Other bowyers use deer sinew in the construction of Turkish flight bows, so it is definately up to the task.

Tradition composite prods often had no wooden core and were made from ibex or ram horn. Recurves were usually static and spliced into the end of the limbs- a bit like the siyah on a Turkish bow.

check out this link:

http://redhawk55.wordpress.com/category/crossbow/

This guy, while being a bit rough, certainly has some good ideas on how to put a composite prod together. There is also a great picture of a static recurve composite.

Regards

James

Geezer here: mouthing off about horn/'sinew composite bows about which I know precious little.
So here's the benefit of my ignorance. It is apparent to me, having perused some of the available literature on this subject, that the making of horn'/sinew composite crossbow prods (note composite recurves, like Turkish bows are substantially different) that this is a very tricky craft that was developed over a thousand years of trial and error. IF I was going to try my hand... which I am not, I would start by doing research concerning what was done in period, followed by tracing the footsteps of modern craftsmen who can report some success in this endeavor. I would NOT strike out on my own, with untried materials and unknown adhesives, assuming I know better than those old guys. If you do that, you're gonna induce a whole new stack of unknowns. So when the first effort fails, whatcha gonna blame it on? I say keep the variables to an absolute minimum. If it looks like medieval horn/sinew laths were based on Kabingi-wood from Faroffistan, I would start with Kabingi-wood. If the masters suggest only the back-sinew from left-handed Simpson's gazell, I'd make an effort to get that. As tempting as it is to use an exotic wood or off-the-wall modern glue, I think you should stick as close as possible to original materials. Not because I think those are better, but because they have a better chance of producing a successful product.
Does this make sense, or am I just talking outa my armpit again? Geezer

Geezer,

I understand what you are saying, but I would still encourage this craftsman to go ahead. Albeit in stages. Sinew backing and binding does and will overcome many errors. If he succeeds or fails, I look foward to his feedback.

I would make the suggestion to do away with the horn belly for the first attempt. Sinew backed ipe, while not historic, should preform very well, look good and does not involve the added (steep) learning curve of dealing with horn. I have wrecked lots of good horn trying to make a decent horn bow.

Regards

James

Swatovator,

Geezer and Kiwijim have some good points. A composite prod is a thing with a lot of technological problems which have to be addressed. Sometimes it is better to address them one at a time if you can. Likewise, it is best to begin with things that others have already demonstrated to work, rather than to reinvent. That is to say, it is better to *rediscover* before trying to *reinvent* the technology.

Specifically; if you have not worked with sinew before, it would be an excellent exercise to make a sinew backed prod or two to work out the basic problems of handling and gluing up the sinew. I personally have built a number of such bows with an eye toward getting ready to make horn and sinew composites. I have to admit, that that is where the project stalled, and I have not moved on to the horn part. On the other hand, I gained a lot of valuable experience which will serve me well when I finally get back to the project.

Mac

swotavator wrote:
Yes, i have sketched it multiple times.

Excellent.

swotavator wrote:I intended on grooving it but i don't know if this will weaken its back. it might be better to glue the horns straight on. Maybe i will just roughen the surface.

It is clear from the pictures of sectioned bows that grooving is universal. The horn plates are grooved. The wood (if any) is grooved. The surface which will take the sinew is grooved. What is not clear, is how much the grooves ae intended to serve are "finger joints" and how much they are intended to give the surfaces "tooth" or perhaps ease the transition from one material to the other. Usually, the sections show the ridges and vallys fitting pretty neatly into one another but sometimes there is a mismatch, and the pieces are fitting "tooth to tooth". My current guess is that the intention was to make the pieces interdigitate, but at the ends of the horn plates, things get a bit haphazard. That is to say, I think the plates were all grooved an uniformly and as straight as possible, but at the tapered ends of the plates, things don't always match up. In the final analysis, though, a certain amount of mismatch must be permissible.

swotavator wrote:That is a very good hint on the recurve. The idea of progressive layers of sinew taking different amounts of strain makes sense. I think i will glue in the recurve in steps. perhaps 1" at the horn, 2", 3" at different parts of the sinewing.

If I understand what you are saying, you intend to *increase* the recurve at each sinew layer. To achieve the effect I was thinking of, you would need to *decrease* the recurve somewhat for subsequent layers of sinew.

swotavator wrote:Already bought the cowhorn, so no going back on that. Though i thought i heard of people using that, historically. Also were there water buffalo in medieval france?

I suspect that buffalo horn was an expensive import commodity from the East. My understanding is that it was the horn of choice for Asian and Middle-Eastern bows.

We have documentary evidence for goat horn being supplied to a crossbow maker (Peter the Saracen) in 12th C (?) England. We also have modern descriptions of bows that suggest the use of whalebone (baleen).

I have read modern accounts that suggest that cow horn is somewhat brittle, when compared to buffalo horn. On the other hand, I bet it will work better than nothing, and you can use what you have to learn a lot about working with horn.

swotavator wrote:Wondering if I really need the rawhide wrapper. It is very thick. perhaps i can get away with a linen wrapping between the paper and sinew?

I think some sort of circumferential constraint is probably necessary to keep the plates of the horn core from buckling and becoming unglued.

I don't think linen is going to do it for you: it has very little elasticity. Here, again, it is probably best to go with the traditional material. This hedges your bets on the success of the project.

swotavator wrote:Progress is good. I am almost done with the roller nut (4.8cm by 3.6cm ipe with horn reinforced prongs), and have all the pieces of the stock (walnut, ipe, wenge, maple).

I, personally would use iron for the reinforcing pins, if I thought they were necessary at all. Have you got the grain of the wood oriented vertically? I don't think that horn has the shear strength you want for this. Historical nuts typically made of antler, and the ones for the biggest bows have iron pins through the "teeth" or "fingers".

swotavator wrote:The ipe is such a bitch to work, I had to make a macguyver lathe with a drill, rat tail file, and sand paper.

We didn't have MacGiver when I was a kid....I call that the "poor man's lathe".

You can make an adequate nut using a "hole saw" and a drill press. If you take the pilot drill of the saw, and grind it down to about 5/32", you can make a nut with a concentric hole in one go.

Mac

Mac

I too wish to one day (when I am ready) tackle an authentic composite prod.

Two good general how-to resources I have and would recommend deal with composite bow making, which I realize is not the same as the crossbow prod, but any knowledge is a good thing. They are "How to Construct the Asiatic Composite Bow" by Jeffery Schmidt and John McPherson. In particular is Jeff's method of grooving the wood slate and horn, which is very simple and produces what appears to be excellent results. The other is a four hour long DVD / tape called "The Way of the Bow, The Korean Horn Bow." This one is a slog to get though, as it is basically four hours of observing a bowyer make a bow from start to finish, with little if any English dialog, but there is a wealth of info there if you have the patience to get through it.

My biggest question at this point is the nock ends. How were they reenforced?

Ah, one more thing. Are there available fiberglass prods that appear to be medieval composite prods? I seem to recall this from somewhere on the site, but does anyone know if these are available and vendors who sell them?

Thanks for all the advice guys.
The roller nut is done, starting work on the stock. The nut is definitely oriented vertically, and only the string prongs are horn. I did drill in a piece of steel for the tickler.
I have not yet cut out the ipe belly. I picked ipe because i had some (and not yew) and i knew it was tough. However, if maple was used historically, i would much rather make an attempt with that. sooooo much easier to work. I will groove it, too.
I am not married to making this high draw weight, so using maple will help. THinking of doing 5/8 thick tapering to 3/8. Also keeping it low weight will give me some lee way with the more brittle horn.
I have been playing aroudn with the cow horn, however, and it is pretty supple. I think it will work.

I was told spiral cutting the horn is the most easy way, but I am thinking that perhaps this will create grain run-off problems? probably not an issue, however, with so many slats glued together.

Stoneagebowyer,

Thanks for the info on the videos!

Here are some links I found.

To buy the video outright.... http://www.amazon.com/How-Construct-Asiatic-Composite-Bow/dp/B000EE062Y

To download it from Amazon...http://www.amazon.com/quot-How-Construct-Asiatic-Composite/dp/B000YE3LLW

To watch a pirated upload on youtube...https://www.youtube.com/watch?v=cISUlV895xA

Here are a youtube link for a group of videos about Korean bows. Some of them, I have vewed before, and some are new to me.
https://www.youtube.com/watch?v=1t_31Bxn7vQ&feature=results_main&playnext=1&list=PL8D331C2E7B1A5075

Is the long video about making Korean bows available? I have not found it yet.

Mac

swotavator wrote:

I am not married to making this high draw weight, so using maple will help. THinking of doing 5/8 thick tapering to 3/8. Also keeping it low weight will give me some lee way with the more brittle horn.

If you are falling back to the idea of making a sinew backed wood bow (without horn) for practice, any wood that is good in compression will work. If you are still thinking about the whole composite enchilada, I would recommend oak; like the surviving examples.

swotavator wrote:
I was told spiral cutting the horn is the most easy way, but I am thinking that perhaps this will create grain run-off problems? probably not an issue, however, with so many slats glued together.

The pieces of horn in the surviving bows that Richter illustrates are not all that long. That's one of the surprising things about the horn core. I wish I could say I knew whether the grain direction of the horn is important, but I just don't know. I would personally go with the grain where possible, even if it means shorter pieces of horn; but that's just a hunch.

Mac

No problem, Mac. You can get both videos at 3 Rivers Archery. http://www.3riversarchery.com/Books+DVD%27s+Bow+Building+Korean+Horn+Bow%2C+DVD_c42_s33_p287_i7821_product.html

Great company, fast service, and lots of other stuff crossbow makers can use, such as B-50, bolt heads, etc.

However you handle making one of these prods, sw, I am guessing you will have a very long process aheady of you. Probably at least six months. An Asiatic bow takes many months to let each layer of sinew cure, and with this mass of sinew, I would not be surprised if it takes over a year to initially cure. One of the most valuable things in the Korean video is the outer covering he uses for his bows. If I recollect correctly, he uses birch bark that has been cured in salt water. Also, the glue making process is covered. This guy uses fish bladder glue, and it is supposed to be a very stinky process to cook down the bladders. I bet regular hide glue or even Knox unflavoured gelitan would be sufficient, and less oderous.

Thank you, Stoneage.

Back when I was more active in archery, I used to get a lot of stuff from Three Rivers. That was back when all they had was a paper catalog. I'll have a look at their site.

Mac

No problem Mac.

Here is a link for a guy who build a bamboo and sinew bow without horn as a practice run before tackling horn. There may be some construction insites arbalist builders can gleen. He did a beatuful job, and the Korean bows use bamboo cores, too.

http://www.atarn.org/FAQ/bamboo_composite.htm

Here is a link to the specific video where the horn and wood are grooved.

https://www.youtube.com/watch?v=BZ9Y2H45ipI&feature=related

I will certainly buy the whole video. "If you like it then you should'a put a ring on it"

Mac

This is from the first video I recommended. It is a great investment, just in knowledge even if you never build a composite bow or prod.

Dane

I would just like to repeat Stoneage's question : does anyone know of someone making functional composite prod look-a-likes in a more modern material? I ultimately want a composite bow, but while I wait it woild be nice to get the crossbow finished. cheers Jokum

The only one that I know of that has done something like this is leo Tod http://www.todsstuff.co.uk/crossbows/14thc-composite-crossbow.htm



He covered a steel prod to give it the look of a tradtional composite prod. I believe it is wood that gives the prod its bulkly look. I think the details are listed on Myarmoury somewhere. He might sell just the prod, not sure.

jokum wrote:I would just like to repeat Stoneage's question : does anyone know of someone making functional composite prod look-a-likes in a more modern material? I ultimately want a composite bow, but while I wait it woild be nice to get the crossbow finished. cheers Jokum

Jokum,

I suppose you could take a steel or aluminum prod and glue a thick piece of foam, or other lightweight material onto it. You could then shape it up to look like a composite, and cover it with some light weight skin. You would have to do something more substantial in the middle, however, so that the binding does not crush the foam.

Mac

Thanks for the reply guys, I have looked at Tod's already, but i think ill try to make one myself, teh foam idea was good i thought, or maybe bambo or balsa....do you know of any good, cheap alu or steel prod retailer?
J

You would have to do something more substantial in the middle, however, so that the binding does not crush the foam.

...and the tips as well.

Aluminum prods can be purchase from guys at Darkwood Armory for around $40 I think. The link to their site can be found in the New Member & Useful Links panel under Supplies & Accessories on the right of the forum.

Good Luck

Ivo