Primitive Archer
Main Discussion Area => Bows => Topic started by: BarredOwl on June 06, 2014, 07:03:31 pm
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Hello all. I am new to the site. Have been lurking a while and studying up to get started making bows.
I have been cutting wood like a mad beaver lately so I have a good supply to learn on. I have cut some hackberry to practice tillering before I tear into my pile of osage.
So I sealed the ends of my hackberry staves and split them and peeled the bark off one stave, which came off real easy. It was wetter than all get out under the bark and I was waiting for it to dry off on the surface so I could shellac it when I noticed a little fiber coming off of one end of the stave on what will be the back of the bow. I pulled on it and a thin strip of wood? or perhaps cambium started peeling off and ran all the way to the other end of the stave. My question is. If I peel the bark while it is green this time of year does the cambium layer come off with the bark or was this thin strip that I peeled off the cambium layer that will eventually need to come off?
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Looks like I got carried away with the photo attachment button.
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Looks like the cambium layer to me. I would use my drawknife, blade at almost 90 degrees on the last few inches on one end. Use it like you would a scraper and see if that doesn't peel right off. Don't go deep, just try to gently scrape it away and that should tell the story.
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Also, these photos were taken several days after the bark was taken off and the shellac was applied so it is dried on the surface anyways.
I don't know if it means anything or not but the strip that peeled off has remained white in color and is very tough and pliable even after it has dried.
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We'll I scraped a little on one end and it appears that the cambium is still on the stave. Can anyone confirm if that is most likely the case? And if so what is a good technique for removing it?
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If it's the cambium it should come right off with like a butter knife or something. I would be very very cautious messing with the back of the stave, I usually just very lightly sand the back of my hackberry staves (that look just like that and do NOT have the cambium layer still on, or at most tiny little pieces of it that sand off easily). I guess it's hard to tell when not in person, but MY guess would be that you are looking at wood in those pics. But at the same time it is hard to tell and cambium can look like that too. I can't make up my mind I guess, lol. How's that for some usless advice, ;D.
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My guess would be you have a growth ring there.
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Yeah I might just have to learn the old fashioned way on this one. I live in hackberry heaven here in southeast Kansas so supply is not a problem at all and I didn't cut the best ones I could find to start with. I might scrape a little more and take a close up photo. Another thought I had was is the tree still laying down early wood this time of year and it is porous enough it is throwing me off. I tend to think cambium wouldn't be as tough as the strip that came off. Or maybe the tree is just starting to lay down late wood and it's just a thin layer this time of year?
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That looks like your bow back, but it looks like you can avoid completely, so don't even worry
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Welcome on!
I don't know about the cambium. I cleaned up a few hackberry sapling last year but they were fresh and the bark and cambium came off easy.
I was born in Bourbon County Kansas. Fort Scott precisely. Where you at?
Marco
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I am near Eureka, KS. I am thinking the cambium came off and I am looking at the very beginning of the latewood growth.
Doesn't it make sense that for white woods where the bark just comes off to make the back that it would be best to cut a tree late in the growing season so that the late growth is as thick as it is going to be? It may not be critical but might tend to be a little better I might think. Just something I thought up the other day, might not be anything worth worrying about.
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Doesn't look like cambium layer but outermost growth ring. Luckily it's on the edge and you got plenty of width to still work with. Cambium layer will be brown on hackberry and other white woods.
Tracy
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First off, welcome aboard! What you have there is the very beginnings of the latewood ring over the early wood. It's about a month and a half too late to just peel the bark for your back on whitewoods in your area. It's not ruined, but you will need to chase a ring on it. You have a very short window in the spring to cut whitewoods and a longer window in the fall. I generally cut mine from the first of Aug til mid Sep. The SAP will still be flowing so the bark comes off easy and the latewood is mature enough that you'll have no worries about ending up with an early wood back. I hope that helps. Josh
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(...) the latewood is mature enough that you'll have no worries about ending up with an early wood back.
Why would you worry about an earlywood back? The back ring still consists of unbroken wood fibres within one ring. The strongest back possible.
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If I were to give a short answer, I would say that earlywood in ring porous wood is fluffed up junk. But that's not my way. Hackberry is ring porous. The earlywood is the part of the tree that draws the sap from the roots to the leaves. The biggest part of the trees circulatory system. As such it is mostly thin walled voids with the sole purpose of moving sap. The latewood on the other hand is the strength of the tree structurally speaking. Both are made up of continuous wood fibers, but fibers with two different structures and purposes. Since were talking the back of the potential bow or tension load. The structure of the latewood is made up of ALMOST solid wood fibers densely packed together so that they support one another and resist deformation and share the workload. The earlywood is consisted of thin walled straws loosely packed together to move the maximum amount of sap. More voids than solid wood. So the latewood is not only stronger fibers, but there are more of them to take the strain. Sort of like the difference between a 23 strand fastflight string and a 10 strand b-50 string. There really is no comparison in strength. Josh
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BTW-before anyone points out that the endgrain pic is coffetree and not hackberry, I'm well aware of it. It is the first ringporous pic I found that illustrates the difference in structure between the early wood and late wood. Also this opinion on the earlywood being fluffed up junk is not based on Google academics or just some repeated dogma. I came to this opinion the old fashioned way, by breaking bows. Josh
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I wondered about the timing of harvest on white wood. I just hadn't confirmed it with anyone but seemed to make sense to me that would be the case. Chasing the ring on this stuff may be real fun!!?!?
Now it sounds like the next thing to figure out is the tempering procedure I will need to use on this wood. Any pointers to a good source of info, perhaps a video on the subject?
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It sounded as though you had figured out the timing bit already. I was just confirming the notion. Chasing a ring on that will be pretty easy if you have a draw knife and maybe a scraper. You won't have to remove much material to get last years ring. Generally speaking, whitewoods are slightly more difficult to chase a ring on due to the hard to see rings. The best way to alleviate that problem is to work in natural sunlight instead of inside. Another little trick is to have a wet rag handy. When you can't see the rings just give it a swipe with the rag. The early wood fibers will fluff right up. Heat tempering the belly of hackberry is good practice. When you get it to floor tiller, then you can worry about heat tempering. There are several threads covering the process in good detail, but I can't think of which ones to direct you to. Josh