Primitive Archer
Main Discussion Area => Bows => Topic started by: ekalavya on October 31, 2015, 06:09:25 am
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i heard and read several times that cherry needs a backing , because cherry
should be good in pressure but weak in draw.
i thought why not use another suitable wood for the backing ... maybe cut or
taken from another tree with intact back and then glueing it on with normal
wood glue or so.
However , I got no clue, which wood would be suitable and how thick it should be.
Would 3/16" and any wood good in draw do it ?
All I read until now concerning the topic was a russian text "igonina i v izgotovlenie ostyatskogo luka"
which was a pain to translate for me --- and some parts still remain a mystery for me.
There birch is used and its just half as thick as the pressure wood - taken from some kind of pine or
spruce.
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Not sure how using a sawn stave would work because of the crown, unless it was a very large tree? Never tried it,but rock maple would be my first choice for cherry.i did one with white oak slat that worked well.think pat m made note of that method in the past.
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The late and great Jimmy Taylor made thousands of hickory backed cherry bows so I guess hickory would be a good choice.
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Any "good" tension wood will match up well with Cherry. A single growth ring backing is fine. Crown doesn't matter and in fact might be preferable.
I don't like knots in my bows so if I run into a grown over knot that's going to be in the finished bow I'll just keep reducing until it's gone and turn the bow into a backing strip instead.
I only cut wood that has no visible knots externally although no tree is not going to have grown over knots deep in the stave.
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Thanks for the answers.
Rock maple is what is called sugar maple (Acer saccharum) with saccharum
meaning sugar. However , it does not grow where I live, although other kinds
of maple are there like Acer platanoides and Acer pseudoplatanus.
Is there a test I can/should make to test the qualities of the backing wood?
(probably something like take a 32" long and 1/2" thick and wide piece out of the stave
and then bent it until it shows 1 or 2 " of set)
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I've never been impressed with those two types of Maples judging by the way they snap every time we get a strong wind here where they are planted as ornamentals.
I think you get Maple more similar to our Rock Maple where you are.
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I did a hickory backed black cherry leaving the hickory to thick at 1/4" or less thick it shot ok but not exceptional.it developed chrysals after a couple hundred shots.i like maple because of a lower s.g and less bend resistance than hickory imho, although opinions may differ.
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I've had success with thin quartersawn hickory backing strips on black cherry. As thin as 1/16". The thicker the backing, the greater the chance of it crushing the belly surface wood.
For these bows, I decrowned the cherry staves, brought the working limbs to about 5/8" thick at the dips, tapering to 1/2" at the tips, and then glued in a nice gentle overall reflex. Titebond type wood glue will work well if the gluing surfaces are relatively smooth, and a good epoxy like Smooth On or Unibond works great if the surfaces are rougher due to grinding or toothing plane work.
These cherry bows are lively of cast and feather light to carry.
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How difficult was it too decrown ?
The germans i asked , all say ... maybe one out of twenty will work ... the rest is lost ,
so better forget about decrowning.
-http://bogensportwiki.info/index.php?title=Datei:Decrownen.jpg
they even put a picture in their wiki for explanation. Don't know why they almost ever mess up
with decrowning.
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I like maple backers, why not just use rawhide
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raw hide ... i heard rumours that there is suitable raw hide in dog toys ... dog chewing toys ...
what is your prefered source of raw hide ?
is the raw hide of chickens and geese suitable/useful for backing ?
are there any side effects , like shrinking with sinew backing ?
after all those questions ... just going to the woods once again and getting a suitable tree
at least seems easier ... although this "decrowning" seems to be such a problem ....
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The chew toys aren't the best source of rawhide you should be able to get it at a leather supplier in two inch wide strips or from echo archery or three rivers maybe even eBay
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Sinew backed cherry makes a damn fine bow. For lumber white oak, and hickory are my top choices
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I thought about it. Until the cherry is dry there is plenty of time deciding for the backing.
Some guy, mentioned different forms/cross sections for tension strong wood and for compression
strong/tension weak wood.
-https://primitivebows.wordpress.com/articles/tension-and-compression-some-theory/
There are even paper, burlap and bark backings , which have the advantage of easier
available backing material. (don't know how good they are or said to be)
Usually when splitting a stave into two halves , then flatting them at the splitted site and then
glueing them together should be no problem ... into making it a bow. So why not replace one
splitted half with another wood good in tension. Seems worth an experiment with a small bushman
style bow for it does not require real bow wood , but just ell long branches.
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I once made a nice ash backed cherry, where the ash was 1/8 th thick,
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just noticed your name 'ekalavya' wasnt he the guy that got his thumb chopped off by Drona???? for sewing arjunas dogs mouth shut with arrows!!!
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well, he chopped the thumb off by himself ... because Drona demanded a payment , because
he claimed to be his disciple or apprentice ... at least so far , as i can remember the story ....
as for all the question , the answer must be in trying it out ...
i once again read Tim Bakers chapter in the TBB 1 ... I guess he used 18" and 1/2" x 1/2" inch
for testing , because he wanted to have a quarter of a bow ... he further writes that the finished
bow should have 66" , so my best guess is he calculated 10" for nocks and handle and that
in fact he tested only 14" out of the 18" sample wood and so giving his measures or test samples
one could use them for building a 58" bow with no real handle.
The deeper i get into bow building the more i want at least do the tests or experiments correctly.
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Ek, it is a lot of work, but very possible to make a backing from an ash tool handle, like a shovel handle, or an ax or pick handle that is hickory. You have to look at a lot of them, maybe go to two stores, but when you find one with straight grain, both rings and radial grain, it works great.
If you get an ax handle, saw it in half along the widest part the whole length, then plane or saw off the excess from each half.
If you get a shovel handle or rake handle, look for one that has thick growth rings. and chase off the rings that stand high one after the other, until the part that will be the back is wide enough and most of the roundness is gone except on the edges. So, it is more like a fat rectangle cross section, not a circle. Then saw that into two halves and work the sawn side flat and even thickness.
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Also, again it is a lot of work, but little elm trees grow EVERYWHERE. If you find a small thicket of elms and cut a 10 cm tree with no knots on one side, you can take a backing off that. lots of sawing, lots of sanding, but you can do it with hand tools.
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Today in the library I reread the chapter on TBB 2 from Paul Comstock about the early
bows of europe. Therein he mentions the lost Stellmoor bows , which were made from
some kind of pine compression wood without any sapwood at all.
... and there came the interesting part ... they had no backing at all , and the back was
the splitted side or what's usually called "the wrong side as the back".
However they had the right "cross section" (D-shape) for a bow wood strong in compression
and the perfectly flat back perfectly fitted in.
And i thought that's it ... this way one can make a bow probably easily from 2.5" in diameter
branches of pine or 2.5" in diameter saplings of black locust.
(i measured a 5cm black locust stave i have at home ... and it has 3 cm of core wood)
The core wood is easily recognized by colour .... just the mark channel ( the ring or channel
in the center of the sapling) to be removed and voilà! the rest is done very easily without
any kind of decrowning or chasing a growth ring.
Sounds good , if this true and what he intended to say in this chapter.
@Springbuck
I never seen Hickory ... so how could i be sure a axe handle and so on is hickory ...
suppose that is what you meant ... usually they do not write or mention the wood the
handle is made out of ...
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Sorry , for mentioning the chapter in TBB 2 by Paul Comstock ...
I could find out it's "Ancient European Bows" which got translated to "Bögen der europäischen
Vorgeschichte" (which would be "bows of european prehistory" or so) and the wood mentioned
also is wrong in the translation, because there is no "Schottische Kiefer" but a common central
european pine ... usually named "pinus sylvestris"
Although it's mentioned in TBB 2 i could not find any picture of a reconstruction or replica
until now. And it is getting worse , some books ( for example Das Bogenbauerbuch (~ the bowyers book) )
even saying politely Comstock completly messed up on this.
Comstock himself in this Chapter mentions a walnut reconstruction by Tim Baker of a so called
"bow with reversed back" "backward bow" "Rückwärtsbogen" .... (could not find the original)
So i guess it's somehow working ... but even bowstring out of paper worked and yes , i shot
a miserable 15 lb hazelnut bow with it.
It's a pity but translating does not mean "making up words of your own". well, Luther did this
with the bible , but that was centuries ago and he had no wiki to help him out.