Primitive Archer
Main Discussion Area => Bows => Topic started by: Bernal on November 15, 2011, 10:31:16 pm
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Hello!
I've been reading the forum for months and visit several times a week for my fix of inspiration and tips. So I want to start with a big thank you to everyone.
I completed my first bow today. Hurray! I can't wait to get started on my next now. I made a lot of little mistakes here and there along the way, but I'm reasonably happy with the results.
The bow is 71" tip to tip, 69 1/2" nock to nock, 49# draw at 28". Made of red oak from the local hardware store and finished with Watco Danish Oil (dark walnut stain). Leather grip with a removable horn arrow rest.
(https://lh4.googleusercontent.com/-oTUUrptuJRM/TsMCn5TFM4I/AAAAAAAAA14/T5kn1XfAhFA/s800/IMAG0160.jpg)
(https://lh3.googleusercontent.com/-lMjc96G87pE/TsMCoZUS1GI/AAAAAAAAA1U/ql-O9dB_zwE/s1152/IMAG0162.jpg)
(https://lh3.googleusercontent.com/-AJj6Qpm9YkI/TsMCoj-lY1I/AAAAAAAAA1s/jMdnGTvphqU/s1152/IMAG0163.jpg)
(https://lh3.googleusercontent.com/-QxitTLfJrk0/TsMCow4IJCI/AAAAAAAAA10/78QxcGgQyOM/s1152/IMAG0168.jpg)
(https://lh6.googleusercontent.com/-j439dIU2poo/TsMCpbJBmqI/AAAAAAAAA04/J9m7AkJEPUg/s720/IMAG0176.jpg)
Here are the chrysals that appeared late in the tillering process and are on the belly of the slight hinge in the right limb. My limited understanding of chrysals is that they aren't an indication of imminent failure, but as long as they don't grow into full on cracks they just cause the bow to be a bit more sluggish than it would otherwise. If that's wrong, please correct me.
(https://lh3.googleusercontent.com/-65q7QpVSXSU/TsMCpPKzVKI/AAAAAAAAA00/EwlTfz8Hv3E/s720/IMAG0170.jpg)
I haven't gotten to shoot it yet, but will take it to the practice range tomorrow night and see how it shoots.
Now... I think I'd like to try hickory next! (yes, I'm hooked)
--Bernal
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Tiller looks good now. I don't see a hinge. Where was it? Did you fix it. Too bad you got some chrysals. The hinge probably caused. They can be fatal to a bow. The bow could eventually fold on itself. Not telling how long it would take. I assume you fixed the hinge. You might try gluing some rawhide over them. Congratulations on your bow. Jawge
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You will love hickory.
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Good looking bow, nice detail work.
Chrysals are supposed to be caused by either a bad design or imperfect tiller. I have had 4 red oak board
bows develop them after thousands of shots and they all cracked. Mind you the chrysals appeared and within a hundred arrows
it was all over.
After autopsy I think I found my mistake in tillering and it was common to all four bows.Hey I am a green bowyer . But, I also
believe that the wood has been treated in such a manner that it has become dry and brittle. For whatever reason it will
not rehydrate.
Built a ROB bow yesterday and before shooting it in I bathed it in linseed oil. The wood looks better but we'll see.
Lane
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A bow is under tremendous stress at full draw...and if the chrysals are in one spot. That is the weak link...I wouldn't call it a long lasting bow and it could hit u in the head in the future.
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Welcome, congratulations, and im sorry to hear about your chrysals...but on a bright side it is a first one done and the addiction has started >:D
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Around here we have a saying, "If you ain't breaking, you ain't making." Many of us believe you have better opportunities to learn from the bows that fail than you can from one that just magically appear. Welcome to the addiction, it's worse than the Hotel California where you can check out any time you want but you can never leave.
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A chrysal or compression fracture is where the wood fibers on the belly have basically been 'asked' to take more compression than they can take. Unfortunately they are permanent. They occur when a section is either just plain weaker than the rest of the limb or there is a stiff spot on the tipward side of where the chrysal is. Either way the area is just too stressed. If you get them evenly distributed everywhere on a bow then give yourself a pat on the back for good tiller but make the next one wider for the same draw weight or a couple of inches longer.
My advice would be to make the same design again for your next bow.
Can you see how the bend on the right hand limb is more concentrated in the inner third or so of the limb? Also the tips on both limbs are a little stiff for a pyramid bow - this will increase stress on the inner limbs. A pyramid bow should bend in more or less a perfect circle but slightly flatter out of the fades.
Good luck with your next one.
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Mike, you nailed it. The more concentrated bend in the right limb is where the hinge appeared as I tillered through the 20" draw region. I worked it out for the most part. The chrysals are lightly distributed over about 12 inches of that part of the belly. Getting the tips to move a bit more is a goal of mine for the next bow, for this one I didn't address their stiffness aggressively enough early on and hit my target draw before I got them to bend appropriately.
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Making a perfect first bow is the perverbial white whale, always talked about but rarely seen! That being said you did better than most by not having to make your first into a kids bow because of impatience and taking off too much wood. 49# is a perfect weight for a bow Imho. Add to that that you did get the tiller pretty good. now you just do the next one taking into account what you now know you did wrong. Btw very nice looking bow, hope it holds up awhile so you can shoot this one while you build your next.
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Oak is very sensitive, and in my experience forms chrysals easily. It makes a great, affordable bow but can be finicky. For what its worth I have an oak board bow from a long time ago that formed frets like a dog right off the bat, then it stopped and I just kept shooting it. It still shoots to this day with all kinds of fractures on the belly, both limbs have plenty of them! Apply that exact same tiller job to osage, hickory or elm and those fractures wouldnt be there.
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Just me, but I think those frets could be more from soft unseasoned wood more so than any tillering job. Your tiller does look good enough to distribute the stresses. Do you know the seasoning time on the wood?
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Its from a board Artsy. Kiln dried Im sure.
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I got to try out the bow tonight and was very happy with it. It shot accurately and felt comfortable to shoot. It was very cool to be able to shoot something that I made myself and to have it work better than the bows I've bought.
After a couple hundred arrows, the belly had more chrysals fairly evenly spread across the working part of the limbs, but they were all very tiny and don't seem to be much of a problem at this time. The bow gained another half inch of set for about 2 inches total set.
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A couple of years ago I went to a primitive bow shoot here in Germany. Nearly every white wood bow had some small chrysals. Its also worth mentioning that I had a tree of heaven bow develop them when shooting in very cold weather; -15c. They are not always the end of a bow either, yours look quite small. I sometimes think that you can make good bows from wood like ash, oak, hazel etc but the wood is always complaining, even when the tiller is to your eyes spot on - some little imperfection in the wood and a little to much pulling and you have problems. In my humble opinion new Bowyer's should use Osage or yew, very forgiving wood that just wants to be a bow in the first place.
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Oak is very sensitive, and in my experience forms chrysals easily. It makes a great, affordable bow but can be finicky. For what its worth I have an oak board bow from a long time ago that formed frets like a dog right off the bat, then it stopped and I just kept shooting it. It still shoots to this day with all kinds of fractures on the belly, both limbs have plenty of them! Apply that exact same tiller job to osage, hickory or elm and those fractures wouldnt be there.
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I think he should strive for perfect tiller before using a wood that will allow for a less than perfect tiller without chrysals . When you are starting out the first thing to really get your head around is how to distribute the stress throughout the limb by understanding the link between front veiw profile and correct tiller shape eg pyramid bow - arc of a circle tiller , parrallel limbs that then taper to tips - elliptical tiller. As wood gets thinner it can accept more bend. If you follow these principles you won't get chrysals bec ause the bending stress is properly distributed. Granted you could use osage with this tiller without chrysals but the wood wouldn't be strained properly - some bits would be loafing and some too stressed. If this bow didn't get chrysals in osage then it should be narrower....to the point where it did develop some!
I think the OP did a great job for a 1st bow but how can he learn if you just say 'make it out of osage and it would be fine'?? You learn by making mistakes in my opion ;)
If you intended to leave the tips stiff then they should be a little thicker than the working limb and taper more than a straight pyramid taper (narrower) the inner 'working limb' would then need to be a little wider and thinner to accept the extra bend without becoming overstrained.
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Great to get that first bow under your belt. :)
Once you have done a few more and really developed your 'eye', you will look at the first one and really pick out the faults.
With woods which aren't the best I'd suggest going for a more 'arc of a circle' tiller along each limb (assuming a stiff handle), as this spreads the bend (and thus the stress) more venly along the limb and gives you the maximum chance of success.
Gotta remember too, the problems that teach us as much (if not more) than the successes.
Del
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Mikekeswick is saying quite a bit in his post. This bow goes a long way toward showing what happens when a hinge jumps out at you. You can bet Bernal will be vigilant from here out on hinges.
Just skipping to a bow wood that will put up with a greater degree of error isn't learning the craft. I'm thinking I should have everyone learn bowmaking on a black locust stave...they are famous for having no patience for bad tillering!
Just get back in the saddle, Bernal, make another 'un. Stick with the board bows for now because they are cheaper to learn from then $70 osage staves. Besides, any osage dealer will tell you that good staves don't grow on trees! Well at least not on every tree. :-[
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The bow looks great. keep workin on them and things will get better.one questionable bow leads to making more . just have fun working the wood......Pete
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man awesome first bow dont let it be your last!!!!! if this is your first i can see some great bows to come.
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man awesome first bow dont let it be your last!!!!! if this is your first i can see some great bows to come.
Thanks... and no, it won't be my last. Just today I bought a couple nice boards from a hardwood store near me that will provide 3 hickory and 4 red oak bows. All have nice straight grain. The hickory is the right size for me to attempt a D section ELB.
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Once you work hickory boards for bows you wont grab another oak board off the rack. Hickory is superior for board bows in my opinion. George T. might get after me for saying that!
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That tiller looks pretty good, but if it had more of a hinge during construction which developed chrysals, unfortunately they don't just go away even after you get things cleaned up. If the chrysals were localized in one small spot, you could do a radiused belly patch. But these extend for a foot or so, which makes an actual repair more effort than grabbing another stave.
You could hang it on the wall or shoot it, keeping a close eye on those chrysals and the tiller shape, and an ear out for any telltail "ticks". If they seem to be growing at all or you start hearing faint "ticks", hang it up. Chrysals are a bit like a time bomb, prone to sudden death. >:D Sometimes they give a warning before cutting loose. Sometimes not. Those don't look "terribly" bad, but then again that's a flat (thin) belly with little meat to give slowly. Be careful if you decide to keep shooting it.
With that said, congrats on the first one. I'm sure you learned alot from it. I've always been a proponent of beginners using a good, clean stave of hickory or osage. I doubt either one of those woods would have developed chrysals, so even if the tillering wasn't perfect, you'd have a fine bow. I know they're expensive, but I believe having skins in the game encourages people to work carefully. :) The real bargain of cheap wood often is realized only later; that successful odds and satisfaction were traded away. I admit it's an alluring trap. I was excited when I bought a $19 Sawzall from Harbor Freight, once...Need I say more?