Birch for bows?

[Big John]

Hi all,

Has anyone tried birch for a basic bow - is it any good?

Also, someone recommended a bowyers book a while back and now I can't find the thread, I'm not looking for the bible trilogy, something a bit more 'affordable' - any recommendations?

Thanks guys,

 

[torjusg]

Of literature, you can find whatever you need on the net. Just google bowbuilding or making bows or similar and you will probably get several hits.

I have made several bows of birch, some very good some not as good. I find birch nearly as good as ash. And sometimes better.

Torjus Gaaren

 

[stovie]

Hi all,

Has anyone tried birch for a basic bow - is it any good?

Also, someone recommended a bowyers book a while back and now I can't find the thread, I'm not looking for the bible trilogy, something a bit more 'affordable' - any recommendations?

Thanks guys,

This article by John Jeffer on this site is a good starting point...just substitute Birch for Ash.

As for books the badminton book of archery is available online here

Also it is worth perusing paleoplanet as this forum has many threads on bowmaking.

Hope this helps

 

[jdlenton]

The bowyers bibles are now a reasonable price in papaer back from amazon i think mine were £12 for the first two and £16 for the third I got one a month for thee months a didn't feel any pinching of the wallet.

James

 

[Bardster]

A good beginners book is "the traditional archers handbook" by Hilary Greenland.

 

[Swampy Matt]

'Bows and Arrows of the Native Americans' by Jim Hamm is a good book and cost me around £5 from Quicks Archery - http://www.quicks.com/

Although the focus is (obviously!) American Indian Bows, the principles in it can be used for all bow styles.

It also covers stringmaking, quivers, bowcases and a bit about shooting.

 

[Tor helge]

I have an unfinished birch bow in my fathers cellar. Obviously I don`t know how it works, but I believe the saami must have made their bows of birch and possibly pine, as most their bows were glued togheter from 2 types of wood.

Tor

 

[Big John]

Thanks all for the advise, I'll give it a go and let you know how I get on.

 

[Robbo]

According to the chapter on 'Other Bowwoods' in the bowyers bible vol 1 Birch makes good bows. Though it depends on the design, the bowyers bibles recomend 2 designs for a first bow.

The first one is for bow weights of upto 50lbs draw weight (though this depends on the species of wood, the denser the the wood the better) and is 1.5" wide from mid limb to mid limb narrowing to 1/2 tips and about 72" long for a 28" draw, bending throughout its length i.e. the handle bends very slightly, (I've built one using this design, dont ask me what kind of wood it is, I dont know, I salvaged it from an old hardwood unit but it shoots fine for being my first wooden bow, its the third bow in this post of mine http://www.bushcraftuk.com/community/showthread.php?t=9970 . )

The second design is suitable for draw weights over 50lbs, it has a non bending narrow rigid handle which flairs to limbs around 2" wide until midlimb, narrowing to 1/2" tips again its around 72 " long for a 28" draw length.

Both designs have flat bellies.

This is from memory as best as I can remember.

Also I'll second stovies recommendation of Paleoplanets archery section, there is a LOT of knowledge on bowmaking there, (and lots of pretty pictures of bows to drool over)

Andy

 

[stovie]

Over the weekend I started on my first self bow. Aquired a piece of Oak (not the best bow wood in the world; can take a bit too much set) but it is fine grained and runs true (I hope ).

2"x2"x8' to produce a longbow style D shape, with a length of 6', draw weight of around 45lbs @ 28".

Have it 80% tillered, the handle needs a bit more spoke-shaving, but it's looking good. Need to make a tiller stick tonite and stand back and take a good hard look...I'm at that stage where I'm nervous about taking more off than I need to

 

[Big John]

I've got an ash sapling which I have split and roughed to 2" wide by 1.5" thick. It's now tied to a large beam in the garage whilst it dries out before doing any more work on it.

There are a couple of small knots on the belly side - are these likely to cause me problems?

Unfortunately it's a bit short at 63" and as I'm quite a large chap I was looking for approx 32" draw - am I going to snap it or should I settle for a lesser draw length? I'm not too bothered about weight, just want something that works for a first effort! A couple of the references I've read say the bow needs to be twice the draw length, in which case I should be ok, but people here have mentioned much longer bows.

I should be able to get a birch sapling next month so I'll make sure I get something longer!

 

[stovie]

I'm no expert, but I think you will be pushing it to get a 32" draw from a bow that size. You might comfortably get 26-28" if the tillering goes okay.

The knot on the belly should be alright, assuming it is not very big. The thing to do is give it a try by tillering to 28", but shoot it at 26"

Being a new venture, the thing is learn your mistakes on this one and produce a great bow second time around...

Not much use, I know, but I'm sure others will guide with more detail...

 

[Grooveski]

32" draw? gulp.

I'm no expert either but I'm inclined to agree with Stovie.

Left straight then even at a 31" drawlength it will be getting very close to a 90 degree angle between the string and the limb even with a fully working handle.
This causes "stack" - where the draw weight is rising disproportionaly to the draw length. As well as making the bow uncomfortable to draw and hold, stack makes it harder to final tiller as you're not getting a real indication of the way the wood is bending.

The usual cure is to steam a slight recurve to the tips. Below is a scale sketch showing two 63" bows drawn to 31" to show the idea.

Having only one bow to my name(which was neither short nor a recurve) I haven't a clue if it's do-able or not. With that kind of bending going on I'd be tempted to back it in case it blows up in your face .

Have fun, good luck!

[Edit - There's nothing magical about 19 degrees, that's just what that model ended up with. 19 degrees should be replaced with "less than it was before you bent it." ]

 

[Big John]

Thanks for the advise guys. I'll definately play it safe and get/make some shorter arrows - as long as they end up going more than 2 meters I'll be happy even if it doesn't 'fit' me properly! I can always give it to my lad, although he's only 4 at the moment so that might be a bit ambitious!

There is a bit of natural recurve in the wood at the moment, but I guess anything could change whilst it's drying out.

Nice diagrams Groovski, is that straightforward CAD or some fancy bow design software?

 

[Grooveski]

Straightforward CAD. You got me curious and I messed around at lunchtime. It's all accurate though, even if it's overly simplified.

Are you sure you draw 32"? Gotta give folk some leeway when they're called "Big John", I mean, you don't want to argue with them, but 32" King Kong only drew 38!
How big are you?

 

[nickg]

Birch will make a good bow - just dont expect it to last forever. The wood follows the string quite readily and will set into a permanant curve quite quickly. The only one i personally made bent through the handle (which isnt anything like as bad as certain eminent authors would have you believe) and braced at around 50lb shot well (before exploding about a year or so later) and with a fairly sharp cast.

Give it a go anyway - its good for experience - and in a bushcraft scenario you will anyway use whatever wood you can find to work.

Nick

 

[Robbo]

Just a thought but if you really want to get a 31 inch draw from a 63 in bow you could sinew back it. The plains indians in america did this with their 40" short bows (though they were only drawing around 25" at most). It would help stop the back breaking in tension and permit a longer drawlength than an unbacked wooden back.

Get some sinew (deer/ cow it doesn't matter) dry it out the pound it until the outer sheath comes off then pound it some more until it breaks down into fibres, comb these into straight bundles then glue 2 or more courses of them on the back of the bow using hide glue made from boiled and reduced sinew/rawhide/gelatin, and as it dries, it will shrink giving the bow some reflex.

This is a very condensed summary of sinew backing (I've never done it myself).

One draw back is that the hide glue is water soluable so don't get it wet.

If you recurved the bow and sinew backed it it would fling arrows like rockets.

Andy

 

[Robbo]

Nick, I'm interested to hear that your birch bow only lasted a year before exploding, one of the authors of the Bowyers Bibles, Paul Comstock uses 'second string' woods almost exclusively and speaks quite highly of birch as a bow wood, though it maybe that American species of birch are stronger and more elastic in compression.

Did you find out what caused the bow to fail? where there any defects in the wood like knots, swirls in the grain etc?

What was the design ? From what you've written I'm guessing that it was a bend in the handle longbow type? I've read that 50lbs is around the limit for this design in a white wood, also was the belly of the bow round or flat?

Andy

 

[nickg]

Robbo

The bow failed about a third of the way up the upper limb. It had taken a set at that point after about a year of use (maybe once or twice a month). This is a fail point that ive seen on quite a few bows (even yew on one occasion). The interesting thing is that two old and experienced longbowmen both independantly cautioned me that it would possibly happen shortly after it was made.

The style of bow was conventional longbow D section and to the dimensions from the quicks archery booklet (some years back). I know that a lot depends on the individual piece of wood as to how and where it may fail.

I think that the issue with birch for bows is that there is (possibly) a much higher likelyhood of finding an invisible fail point that some other apparenty similar woods, like ash and elm which really are great bow woods.

Thinking back the bow failed on draw, which implies a tension fracture, I wonder if the wood would benefit from a good tension laminate on the back- maybe a few millimeters of hickory.

Nick

 

[Robbo]

Nick, if you ever make a birch bow again try it with a rectangular cross section, i.e. keep the belly flat, I've read this is a better design for second string woods as it spreads the work out more evenly across the width of the limb. the 'D' section design concentrates all of the compressive load in the very centre of the rounded belly causing more stress and higher set.

Even easier than adding a hickory laminate would be to glue on a layer of silk or linen fabric, I did this with my longbow as the grain ran off badly on one limb, I used Titebond 3 wood glue for the job, but epoxy resin, hide glue, and possible a good quality water resistant construction grade PVA glue would work also

Andy