Author Topic: Another elm bow in the making, sisal backed (from 30# to 52#)  (Read 4850 times)

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Offline joachimM

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Hi folks,
There's a bit of field elm in my garden in a broad hedge. Dutch elm disease is still quite a disaster here, so very few trees get past a stem diameter of 15 cm. Last summer I noticed that one of the trunks started to die off, and it had been attacked by the elm borer which carries with it the fungus-causing disease. So I cut it and got a 1 m x 10 cm diam billet, split it in four (the other 2 quarters on the pic) and seasoned it.
There was already a bit of borer damage under the bark, so I decrowned it, joined the billets with a Z-splice (not perfect but it holds just fine) and reduced the length to 147 cm (58"). Upper limb 1" longer than lower.

Out of the fades it's only 3.5 cm wide (1 3/8"). Tillered it out to 30# at 28", with belly tempering and mid-limb reflex (which stood its ground just fine after >100 shots), then steamed in some mild recurves and retillered it to 30# at 26".
It's now ready for a fiber backing, as I fear this decrowned stave won't hold up with the recurves.
Will try to get to 40# and see where it goes from there.

Elm is starting to become my favorite wood  :)

thanks for watching

« Last Edit: April 17, 2016, 04:02:33 pm by joachimM »

Offline Stixnstones

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Re: Another elm bow in the making
« Reply #1 on: April 06, 2016, 10:14:43 am »
good lookin splice you got goin there.
DevilsBeachSelfbows

Offline Springbuck

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Re: Another elm bow in the making
« Reply #2 on: April 07, 2016, 07:19:57 pm »
 Boy, you sure ain't letting wood go to waste with them staves!  Looks like a lot of the stuff I work with.  But, those are pretty darn good splices for the shape and cross section of wood you have to work with, so looks like you have it in hand.

Offline joachimM

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Re: Another elm bow in the making
« Reply #3 on: April 08, 2016, 07:03:20 am »
Boy, you sure ain't letting wood go to waste with them staves!  Looks like a lot of the stuff I work with.  But, those are pretty darn good splices for the shape and cross section of wood you have to work with, so looks like you have it in hand.

Thanks for the compliment both of you. The splice was sawn with a crude arborist saw (Silky sugoi 420; a superb saw for having in the car when seeing unexpectedly a pipe-straight knot-free sapling/tree up to 8" wide you cannot resist!), steamed an clamped to make the parts fit, and then glued.

Actually I have a barn attic with 70+ seasoned staves of at least 16 different species (BL, yew, Eur maple, ash, black cherry, sweet cherry, field elm, sweet plum, blackthorn, hawthorn, bird cherry, red oak, pedunculate oak,  hazel, elder, hornbeam... plus some tropical wood boards), most of which is way better lookin than this, but when it comes from trees you planted yourself it has better medicine, you know. Waste not want not. 

Cheers
Joachim

Offline Hrothgar

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Re: Another elm bow in the making
« Reply #4 on: April 08, 2016, 07:59:39 am »
" but when it comes from trees you planted yourself it has better medicine, you know" ....So true.
" To be, or not to be"...decisions, decisions, decisions.

Offline joachimM

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Re: Another elm bow in the making
« Reply #5 on: April 11, 2016, 06:26:36 am »
Started the backing of the bow with sisal fibers.
Here are a few pics.
Took four hay bale cords, that should be enough for this bow. First washed the rope with dishwashing liquid, rinsed it and cut it up into 25-30 cm pieces, and untwisted to get individual fibers. Longer pieces are difficult to untwist and to lay out on the bow and to soak in hide glue.
I take bundles of 1/3 of a ply, soak them in tacky hide glue, squeeze out the excess and put it on the back. I use the handle of a knife to press it flat against the bow's back.

Usually I put it all on in a single go, but only went 2/3 yesterday afternoon because I was in a rush to get some other work done.
wrapped it in bike tubing, heat gun on the tubing to reliquify and squeeze out the excess glue, let it gel for an hour and removed the tubing.
The entire process (washing the cordage to wrapping of the bow) took just over 1 h.

Will give it a second layer in a day or two.



Offline joachimM

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Re: Another elm bow in the making
« Reply #6 on: April 17, 2016, 04:01:29 pm »
After a few days of curing, I shot the bow yesterday and today, has had some 200 shots through it so far.
Sisal still amazes me as a backing material.
Physical mass of the bow plus backing is only 370 g (13 oz), but it draws 52# at 28" (or 49 at my more typical 27")
So a mere 28 g of backing material added 22 pounds to the bow. Projected bow mass for the mass principle for these dimensions (assuming it's bamboo backed) is c 500 g (17.7 oz)
Flight shot it with 250 gr arrows, and got some 250-256 m distance yesterday. Not bad for such a crude bow with less than thin tips and lower limbs (2 cm at 20 cm from nocks, 1.1 cm at nocks)

A FD pic right after backing, no additional tillering done yet. I scraped the lower limb after this to make it a bit less strong compared to the upper.
Yes I know, need to get the elbow down...



Online willie

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Re: Another elm bow in the making, sisal backed (from 30# to 52#)
« Reply #7 on: May 04, 2018, 12:55:15 pm »
Hi Joachim,

I missed this back in 2016, just curious how the bow worked out for you, and if you have done any more with sisal and hide glue? or similar

Offline Carl Galvin

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Re: Another elm bow in the making, sisal backed (from 30# to 52#)
« Reply #8 on: May 05, 2018, 07:35:32 am »
Nice looking bow man

Offline joachimM

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Re: Another elm bow in the making, sisal backed (from 30# to 52#)
« Reply #9 on: May 17, 2018, 03:55:23 am »
Hi Joachim,

I missed this back in 2016, just curious how the bow worked out for you, and if you have done any more with sisal and hide glue? or similar

This  bow worked out great, it was my fastest bow for a long time, but it broke at the recurve. There was a fault on the wood back under the sisal backing, and it split the belly from the back in a weird way.

I've made a few extra sisal-backed bows since then. Still like it a lot, except that it's a bit stiff and coarse material, difficult to finish in a perfectly smooth way. It might benefit from an extra aesthetic finish like fish or snake skin.

Offline Mo_coon-catcher

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Re: Another elm bow in the making, sisal backed (from 30# to 52#)
« Reply #10 on: May 17, 2018, 04:56:43 am »
I bet that rough look would make for a great camo and sheen dulling for a hunting bow. Where do you get your sisal at?

Kyle

Offline druid

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Re: Another elm bow in the making, sisal backed (from 30# to 52#)
« Reply #11 on: May 17, 2018, 05:02:50 am »
Nice bow. And good story. :)

Offline Bob Barnes

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Re: Another elm bow in the making, sisal backed (from 30# to 52#)
« Reply #12 on: May 17, 2018, 07:09:34 pm »
it looks like the baling twine that we use on round bales around here...one roll would last you a lifetime.  :)
Seems like common sense isn't very common any more...