Main Discussion Area > HowTo's and Build-a-longs
Asiatic Composite Build-Along
tom sawyer:
All good suggestions.
I'm not too sure that scraping horn will have much of an effect, and I need to keep a certain thickness to protect the core. Same for thinning sinew. As far as reducing limb width, I could maybe do a little of that. To get from 75-80lb, down to 65 (upper end of my comfort zone) I'd need to reduce width by 19%. I think the limbs are 1.25" wide, so I'd need to bring them down to 1" wide. I might get away with that without losing my lateral stability. I may also taper it in from full width at the handle and siyahs, so it bends a little harder at midlimb. That'll take some of the pressure off the ends of the horn that are butted up against wood spacers.
I also need to do a little work on my nocks ASAP. I cut them straight in, but the string rides on the inner side and very close to the top at brace. I'm going to cut them at more of an angle so the string sllides down in there better. Probably line that area of the nock with some horn too, this walnut is light enough that it might get cut into or split. I'll probably make another string with slightly longer loops, this one's loops rub on the sides of the siyahs. I put duct tape on the area of the lops in contact with the nocks. I bet the bowyers-of-old would have done this if they'd had access to duct tape. They used leather, which is just duct tape with no stickum.
As for finishing touches, I was thinking of covering it in silk and wrapping some areas with thread. I have to deal with the tiller and weight problems first of course. Possibly painting some Chinese symbols on it, something like "Yankee Go Home" or "Communism Rocks". But nobody will know the difference. Actually its more of a Magyar (Czech) bow though, maybe something that says "I'd Rather Be Drinking A Good Pislner". Pilsen is a town in the Czech Republic, after all.
Then its on to the next one, I still have the other two quarters of the gemsbok horn for another attempt and they are the better pieces. I figured I'd practice on the second rate material first. This time, I'll know to make the core more like 3/16" and maybe tapered a bit. Although, you see a lot of these bows and they bend hard early, so I don't know that a tapered core is the right thing to do. Will have to research that one a bit more.
tom sawyer:
More pics on the photobucket website, braced, full draw and just unbraced.
OK I finished watching the Korean hornbow video and learned a lot from the part where he tillered his bows. Basically I had not tillered mine, so it was good that it had the poundage it did. I bevelled the edges of the horn and thinned it a bit towards the middle, also brought down the width of the limbs just a bit. I made the thinner towards the handle, since you ewant more bend near the handle on these bows. I sanded the siyahs and cut the nocks in so there was more of a ledge for the string to ride in.
When I strung the bow I knew it had lost some poundage. I was able to string it using the step-through method. I measured the poundage and found it to be in the 60's, much more comfortable. Also, the tiller was much closer to where I wanted it, the limbs were more even and bending reasonably well. I still need to thin the midlimb on the upper limb a bit, it is bending a bit too hard at the handle in my opinion. I took it out and shot a few arrows out of it. This is a really nice bow to shoot. When first unstrung it showed equal set in each limb, another indication that it is properly balanced.
Now for the bad news. There is always bad news isn't there. I inspected the bow and found that the limb that was bending hard near the handle, had a little of the sinew lifting right in the beginning of the handle. Also, there was a small crack in the spacer wood on one edge, probably from the compression stress of getting mashed by the horn. I heated both areas and got some 2-ton epoxy in both cracks, and it is curing now.
Why did this happen? I think I was just being in too big of a hurry. I should have wrapped those areas with sinew as soon as I saw that the bow had a good tiller and poundage. Instead, I had to take it out and shoot it. Ah well, I can't help myself. Also, I will thin the horn a bit more at midlimb and take a little of the stress off that area.
In any case, I am getting close to finishing this sucker in what I feel is record time. I have to wrap the fades with either sinew or thread and glue, I need to cover the bow with silk and do some decorative thread wraps. I need to put a finish on the siyahs. And then I'm going to call it a bow.
Roger:
Awesome bow Lennie! You quickly came up the learning curve with this one. I bet your next one will be even better. Did you see any problems with the horn splicing you were worried about? Which video did you purchase for the construction of the bow?
Great job bud!
Sparky
tom sawyer:
I got Duvernay's Korean Bow video on DVD from Horsefeathersranch. I only received it a few days ago, I'd already had this thing going just based on stuff I read on the ATARN site. The Korean hornbow is a different sort of animal, long and skinny and VERY flexible over nearly the entire bow. Lots of the techniques can be applied to other types of Asiatics and even backed longbows. It was worth the money.
The parallel splices have held up really well. One has a little more of a gap than the other but there's been no sign of anything coming loose. Im happy with that part of the project. Although, if I'd been more careful when I was flattening the gemsbok horn, I might not have had to split them in quarters in the first place. I'd have had enough horn to run over the handle in that case. That would have been better than the cut and paste approach I took, with the wooden handle piece on the belly side. But this way, I have enough horn for two of these bows. Its a cheap way to go, I got the gemsbok horn for $30.
I'm hopeful that with the glue, and a good solid wrap job, I'll have a shooter right out of the gate.
PatM:
Lennie, There are plenty of examples of composite bows made with multiple strips of horn.
I'm curious as to why you didn't reflex the bow more. According to Tim, the bow should only shoot as well as say a sinewed osage of the same profile. Unless of course you draw it much further than you normally draw to maximize the sinew /horn potential.
The drying time seemed a bit short. Have you beeen hanging out with Thimo lately ? :) Pat
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