Primitive Archer
Main Discussion Area => Horn Bows => Topic started by: MattZA on October 10, 2019, 01:15:25 am
-
Hi all,
I've started playing with a Turkish shaped horn bow build. Not having Adam's book, I've been working with information from various places across the internet and TBB series.
Being limited to very few materials and experience, I'm treating this as a learning curve and an experiment. I'm fully accepting that it may fail due to incorrect materials and mostly my building technique, but as I say, it's a learning curve for my next attempt.
I'm aiming for a Turkish shape bow, pulling anything up to 50# at 29". I've chosen to use vertical bamboo as the core, with Gemsbok horn on the belly. I'm waiting on a butcher I know to finish removing the sinews from three South African antelope. Two wildebeest (slightly smaller than an elk) and a single blesbok (about 25% bigger than a whitetail deer).
I'm sure I've broken every rule in the book so far, but here are a couple of photos. I've made a bit of progress since then, and have the horn glued on the entire belly. Next I'm going to glue my handle onto the back, shape the bow a little bit, and then start preparing the back for sinewing.
If you have any advice or questions please feel free to voice them. I'd very much like to get more discussion going on the building of these magnificent machines.
Matt
-
Here's a photo of the siyah being glued in. I opted to use Garapa wood. Despite it being a tropical wood, I've found it to bend well enough and to glue very well. It's very stiff, and slightly lighter than Osage.
I hand spliced the Vs, used self-made hide glue (and a little gelatin). There's a bit of a gap at the end, but the belly side of the splice will be covered in horn, and the back side will have a second strip of wood laminated over it to provide enough thickness and enough wood for me to shape the outer limbs.
-
Here's a quick picture of the core pre horn and sinew.
I'm assuming your first thought is that it's too thin at 3/8". I agree and am going to add a cut-to-shape laminate on the back from the beginning of the kasan.
The handle (white ash) is going to be glued on the back as well.
I'd love the thoughts/ideas of experienced horn bow makers here. Is it doable to build it like this?
-
The horn is another area I'd like to have a discussion about. Being the first time I used Gemsbok horn, I wasted an awful amount of it, but decided to use what I have. That way if it fails, I can see how and why it failed.
I had to use 3 pieces. The short piece is obviously at the handle, and the same length. The longer pieces have since been glued on and will reach the far end of the kasan by the time I finish feathering them out.
My major concern is width and thickness. There is a very slight taper in width of the strips, and they start about an inch wide. Also, instead of leaving the visible side of the horn in its natural crowned shape, I opted to sand a small flat section across the top of the crown to try and spread the load of force. This means my horn is probably only 3mm thick along the "de-crowned" crown.
Any advice here would be very much appreciated.
-
Possibly! But I suspect the core will fail. I use that boo in glass bows all the time and have seen how poor the glue joints are sometimes, they also don't use a great glue in the first place as the stuff is only meant to sit on the floor haha.
Good luck with your build.
-
And finally, this is just a photo of the wrapping that I used to put the horn on the belly. My experience with this is fascinating. Initially I thought it might not be as tight as traditional C-clamps, but boy did I learn a lesson there.
It's a good thing I've left the core 1 3/8" wide, because the wraps had no trouble crushing the edges of the core, leaving waves along the outer limbs that I'll shape off when I begin carving it.
-
It isn't that the hoen will fail more that gemsbok tend to be too narrow and thin. In a way it is better to cut them into narrow strips and then glue the strips in parallel on the belly. This way you waste a lot less and get better thickness to work with.
If you are going to use a section in the middle to 'lengthen' the strips then max length should be 3 inches. Any longer and the joint will be in a bending section. Any joint in a bending section will fail.
the horn only needs to go about half the length of the kasan.
-
Hi bownarra,
My immediate thought was the same as yours - the glue used is likely to fail - especially in the areas that have been steam bent.
Thus far though it's surprised me. The glue holding the pieces together still seems absolutely rock solid. I boiled an offcut for an hour to test the glue. I then bent it to see where it would break, and interestingly it survived a similar amount of force to an un-boiled sample (approximately the same force as maple). Interestingly, it also didn't show any signs of failing at the glue. It broke in tension like any other wood would.
Assuming I use a normal maple core next time, what kind of dimensions would you recommend I start with? By that I mean when it's still nothing more than a block of wood.
-
Hi Matt, good to see your post. One of the things that has surprised me about these bows is how thin they are. The jury is still out on how much DW mine will have but I was down to 6-7-8mm thick for both the horn and the wood. They are about 3mm each. At one point I got out my other set of horns thinking that I might be able to split then on the bandsaw and double my stash. I don't think they are quite thick enough. On the Fletchers Corner forum one of the guys uses Ostrich tendons. You might be able to find them there.
-
Hi Don,
You're right about the thinness of them. I keep feeling like I'm just holding a backing strip or something ;D
Finding horn the right thickness and length and width is frustratingly tough. I've got another Gemsbok horn which is actually considerably larger than the one I used initially. Once I'm done with this bow one way or another I'll try and use that horn. The only issue is that it's a little bit twisted, which creates another issue altogether.
I was pondering something about horn strips. As bownarra said above, bends in joints tend to cause it to fail, so gluing my horn on in strips could be a slight issue. However, will it fail if it's applied in staggered strips? Think the brick-laying pattern of sinew, but with horn on the belly. I wonder...
In fact I've only ever used ostrich sinews. This bow will be the first time I use anything else. The only problem with ostrich sinew is that it's used everywhere as a dog treat - therefore can be very expensive. My butcher is taking forever to process the sinew he promised me, so I'm considering just biting the bullet and heading to the local pet store.
-
Ostrict sinew is greasy I wouldn't recommend it for hornbows.
I got some a year or two back and didn't like it. It also isn't as strong as leg sinew from heavier animals.
-
I was pondering something about horn strips. As bownarra said above, bends in joints tend to cause it to fail, so gluing my horn on in strips could be a slight issue. However, will it fail if it's applied in staggered strips? Think the brick-laying pattern of sinew, but with horn on the belly. I wonder...
I'm going to go out on limb here but I think bownarra was talking about butt joints in the horn in a bending area. I think it's Persian(maybe) bows that have two narrow strips of horn on each limb. Maybe they only had Gemsbok horn and it kept splitting on them ;D ;D ;D Piecing together a belly like bricks(if I'm following your thinking) would put butt joints in the bending area. I'm thinking it's like cracks in a self bow. Cracks along the length are not a big problem but cracks across are. If you are using two lengthwise strips you may be OK unless the bow is too narrow or the belly is even slightly crowned. Either may tend to separate the horn strips when you bend it. Remember, I'm speculating here, I don't have any more experience with these things than you do.
-
Yea I think it was the Persians. I presume they used Ibex, which is essentially the same thing. As you say, they probably got frustrated with the damn things splitting ;D
As for the butt joints, that why I suggested them in a staggered pattern. That way when there's a joint between two strips lengthways down the bow, there's another strip alongside the joint that is a single piece. Therefore you'd perhaps have enough strength from the other strips to offset the weakness of the one joint. I'm picturing maybe four rows of horn. Each strip is a different length to the next to it.
-
I don't think I'd trust it but what the hey. If you're willing to risk all the work. That may be the reason why everyone kind of slavishly follows the old ways. They're proven and no one wants to risk throwing all that work away trying new stuff.
-
Just get some water buffalo horn! There are millions of water buffalo :)
No your butting strips idea won't work. Only full length side by side strips will work. This was done because it is easy to get full length strips this way and the bow design was too wide for the available width on normal horns.
Any horn joint in the bending section WILL fail. A butt joint will last the longest but it will fail. The compression these bows take is incredible but that is with a solid horn :)
-
Heh, bownarra. I just did a Google search.
Water buffalo horns go for between $80 and $100 for a pair. For my Gemsbok horn I pay $8. ;D
It's for that reason that I'm willing to ask experimental questions and try different ways. Sure, 99.9% chance they'll fail. But at least I can say I've learned something for my next attempt.
I hope that doesn't come across the wrong way, by the way. I still very much appreciate your input, and obviously accept your patient answers to what must seem like ridiculous questions.
It's just when you're making one of these things for the first time, it's all-consuming. I'm always looking at it and asking a million questions in my head ;D
-
theres sheep horn
h ttps://www.worldwidewildlifeproducts.com/store/pc/32-inches-Good-Quality-Large-Ram-Horn-for-Sale-Sheep-Horn-You-are-buying-this-one-for-33-99-66p4140.htm
h ttps://www.worldwidewildlifeproducts.com/store/pc/31-inches-Large-Nice-Quality-Ram-Horn-for-Sale-Sheep-Horn-You-are-buying-this-one-for-32-99-66p4141.htm
Theyre different links
-
Here's an update photo. This was taken quickly at 4:30 this morning before going to work, so it's not exactly professional quality.
Nonetheless it gives an idea of the shape. Note, the back of the bow is covered in shadow, hence the dark line - it's not a horn backing, ha ha. I'll post more photos when I've cleaned it up, etc.
-
There is a guy in vietnam i buy my horns from and so does a lot of better, quite credited bowyers. You can get a readily cut and sanded horn strip for ~16 dollars. Shipping to Finland was something like 15 dollars + some extra for weight. Really cheap anyway. But most importantly top quality.
You can give me a private message if you or anyone else is interested.
Your bow shape looks ok, pretty mild so you will succeed for sure if you don't run into problems with your horns.
-
Hi JNystrom,
I'll definitely keep that in mind if I'm looking.
I saw someone said somewhere that people tend to make their first horn bows with very mild reflex/recurves. It must be because the self bow maker in us tends to look at it and think there's no way it'll survive.
I imagine I'll get a decent bit more reflex when I place the sinew on the back.
-
Question:
How should I build up the back ridge that gives the transition from a flat cross section to a triangular cross section to the tip cross section?
I'm thinking I have two options. I can either glue a narrow, thin piece on the back to kind of give the basic shape and then get the final shape with the sinew. OR I could leave the back flat and then use the sinew alone to build up that ridge on the back. Obviously the second option will use more sinew, but will it make any difference?
-
Well its surely really wise to start easy, no need to rush it with too complicated profiles. There is enough of problems with the materials and glue up anyway. You can still get a turkish boat-like shape with sinew curing and reflexin the bow. This reflex is easier to manipulate to your liking in the tiller process than some overly done wood core kasan bends as some beginners end up with.
For a 50-60 pound bow you would like to have about 7-8mm core thickness in the bending parts (sal) and 9-11mm thickness in the less bending parts (kasan ridge). So about 8mm next to handle, 10mm in the outer limbs. Nocks maybe 17mm.
These bending parts will get sinew and will beef up to 10mm in sal, 12mm in kasan. If you can do this without gluing any wood strips, i would suggest that. Its not that hard to build the ridge to the kasan even with sinew.
I would prefer the sinew over gluing extra pieces of wood.
I recommend to do some copycat work on DC:s measurements.
-
Yes but you will waste a lot of 8 dollars.....don't try to reinvent the wheel :) all this has been done many times before and the consensus has been reached!
Water buffalo horn is not anywhere near that expensive. As Jere said there are lots of other suppliers that a standard google search will not bring up.
The kasan ridge should be shaped from the core wood. That is why the core is left 17mm thick or so at the start. Now your only option is to glue a strip of wood on here and then shape that.
Building it up with sinew is no good. Sinew has little resistance to stretch and so you would need to use a lot of it. Then there is the density, cured sinew/glue is about 1.3 s.g. You would be adding a load of weight right where you don't want it.