Primitive Archer
Main Discussion Area => Bows => Topic started by: stuckinthemud on May 25, 2019, 11:19:05 am
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OK, so, I have never covered or backed a bow and I have never worked with bark in any form. Its Spring and time to harvest some birch bark, first question, is Silver Birch OK? Do I just go for a walk in the woods and pick off bark peeling naturally or do I have to cut out strips - presumably vertical strips so as not to girdle the tree??? Once I have the bark, does it need soaking before use? Then, I seperate the layers down to a single layer, but, is the bark cut into small rectangles, or long strips, and how exactly do you cover a bow, oh, and hide glue, is it OK for this task?
Sorry to be a helpless newbie about this but all advice is needed and welcome.
Thanks in advance,
Andrew
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I'll tell you what I know.
Yes, hide glue works best. Some bows are covered with one long strip, some are covered with little squares, some are covered with mosaics. That's up to the bow's design. Some cultures soak the birchbark in salt water, some just peel it and put it on. Birchbark should be peeled from the tree while it's attached. I don't think that peeling bark is usable, but I'm unsure on that point. Paper birch is the one I know works, but I'm betting silver birch will work.
If you get some bark that works, I should be interested.
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You only need the freely peeling stuff for a bow. No need to wait for spring since you shouldn't be stripping the bark down to the inner bark anyway. Trees which are dead and down actually provide the best bark since the bark seems to fuse together better and be more elastic. The elasticity of the bark varies widely from tree to tree. Some is very brittle and others may stretch like tape.
You can put it on in any number of ways. The easiest is probably in shorter sections slightly overlapped.
Hide glue is great since you can warm up the bark and glue and re-position and work out air bubbles easier.
Peeling it apart and leaving it a couple of layers thick is easier to lay it on. Settle for pieces which are well fused together so it doesn't separate later.
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Thanks for filling in the gaps in my knowledge Pat. The strokes leave me with holes in my recollection.
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It's removed around the circumference of the tree, not vertically. Peeling the outer bark won't hurt the tree as long as some inner bark and all cambium layer is intact.
I stripped bark from a pin cherry log at a sawmill two weeks ago. I had permission. I cut them 2-3" wide and then trimmed them nice and straight and 2" wide when I got home. I then removed much of the inner bark and layed heavy boards on them so they'd stay flat. There's a lot of waste due to how the bark grew in this one. I wish I'd have gotten more.
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If you were making bark containers or say a quiver you'd want to strip the bark deeper but for just a sinew covering using birch there's no need to take more than what's naturally separating as the tree grows.
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Found a downed stem not too far rotted, peeled this piece; is it what i should be looking for, its thinner than paper?
(https://stuckinthemudsite.files.wordpress.com/2019/06/20190610_1540307280257487678212386.jpg)
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http://www.atarn.org/chinese/making_chinese_bow/making_bow.htm
Dont use old bark, its not moisture resistant
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the easy way ;D
https://sagaan.de/birkenrinde/shop/birkenrinde-zum-verarbeiten/birkenrinde-in-platten/ (https://sagaan.de/birkenrinde/shop/birkenrinde-zum-verarbeiten/birkenrinde-in-platten/)
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Thanks simk but my house is a mile from a large birch wood and my place of work is surrounded by an even larger birch forest. Maitus, following your advice I tested the sample and ir is waterproof except for the pores but a coat of varnish/acrylic/oil paint would deal with that I should think?
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You want it more obviously looking like paper strips. Older bark is just fine and easily as water resistant unless it is actually almost rotted. That takes years. I've salvaged bark from trees down for three years.
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So is this too thin? I hadn't bothered to trim it to shape as I didnt have scissors with me? The bark was literally falling to pieces as i peeled it, this is the second layer as the first layer just flaked away,
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No, it's just not a good sample. The good stuff is clear and peels easily into layers. It should be almost like drywall tape and ideally slightly stretchy when pulled before it breaks in tension.
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I wouldn't use bark from a dead tree especially if you have access to live trees. As Pat says, some trees have elastic bark and others it is brittle. You should test before putting it on. The bark can be separated into very thin layers. I wouldn't use anything thicker than 1/32" thick
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Thanks Pat, this sample is transparent, slightly stretchy and about the same thickness as onion skiin or bamboo leaves. I think its Downy Birch (B Pubescens), which is brown barked. Its not pretty to look at but I'm going to paint it. If Pubescens isnt suitable I can keep looking for a fallen silver or paper birch, it wont take long to find something else.
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The paper varieties of birch produce better stuff. The thickness you use can often be dependent on how much the bark wants to separate. Ideally about three to four layers fused together as it often does is likely the best option.
I have used a single layer though and let it basically function about like a layer of paint with the cosmetic features inherent in birch.
I am embarrassed to admit I have so much of it kicking around that I'll grab some to start a fire.
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Thanks Pat, thats all really usefull, I think I'll spend a little while looking for something bit better.
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Couldn't find anything fallen and not rotted so I went with the new option; have cut plenty of 3-layer thick bark pieces, some larger pieces about 8" square, some smaller strips. So, what's next? Do they need to be dried and if so, do I need to soak them before applying to a bow, also, which way up and which way around are the strips placed and do you sand them smooth or leave the finish natural? Thanks again
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You can just shingle them on in strips however you like. Bows covered in bark use every possible configuration from across the limb through diagonal or perfectly straight. Using separate shorter pieces allows you a bit less stress in trying to get the whole piece stuck properly at once.
No real need to dry it because you add water based glue anyway and the bark itself is pretty water resistant.
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Thanks Pat, looks like I'm all set, just need my other half to go out for the day so I can crack on!
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So I got an hour in the workshop and covered the bow, sinew side only, with 2 inch wide strips slightly overlapping and gelatin glue. I tied them down to dry and most are on pretty tight but one has an air pocket, any advice on what to do, should I warm up the patch and tie it diwn or lift it and re glue it, or push some glue under and strap it down?
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Ive heard of this, but never understood it. Usually i peel the bark off when making a bow ;D What benefit does adding birchbark over sinew (or over any bows back) provide? Is it done for performance, protection from the elements, or simply aesthetic reasons? Would you ever want to back a self bow with birchbark?
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Birch bark has a high level of tar, which you can boil out of it under the right conditions, and so is waterproof but as it is stretchy it doesnt tear apart as the bow bends
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The best thing to do is make absolutely sure you are chasing out any bubbles as you go. If you kind of roll on the pieces you can generally eliminate the air as you proceed. You can poke a pin hole in any obvious pockets and press the bark down but the glue still needs to be damp and activated to do this.
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I lifted and re-glued a couple of strips I wasn't happy with and used the tip of a hot iron (sh! don't tell!! >:D) on an air bubble in a strip that was otherwise on really tight, it all seems OK now.(https://stuckinthemudsite.files.wordpress.com/2019/06/20190622_1558113088120452078620735.jpg)
Is it a good idea to bind the ends with thread or sinew?
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stuck-what are we seeing here...is this a very short bow with horn tips?
Obviously i can't comment to birchbark, but i am an "over-binder" of bows in general. This can be seen on my recent sinew backed horn and wood bows. Too much time and materials to take any chances, especially if there is an iffy spot here or there.
I really look forward to seeing some more pics of your bow when its done. You have kind of got me interested in trying this. :OK
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Its a little angry bow, you could say its quite cross!! >:D. Horn tips v-scarfed into yew and sinew bow, somewhere in the region of 110#11" draw, 29" ntn, 2" wide at centre, 1" at tips.
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Angry, cross, clever ;D ;D ;D ;D
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OH! I get it, i get it. Even more cool, cant wait to see her done up. :OK