Linen Backed Bows

[durulz]

OK.
I've started making a yew bow.
Now, because finding a decent length of yew without any blemishes is quite hard, I've had to make a slightly shorter bow than normal - 5 feet.
So, to give it a bit of extra welly, I thought I'd put a linen back on it.
Has anyone else ever done this?
If so, how do you do it? Do you know of any good online step-by-step instructions? Also, can I use glues available from any DIY/hobby store, and if so, which ones?
All advice gratefully received.
Cheers.

 

[Everything Mac]

can't say I have heard of that but I suppose it could work. - I know you can put some fibreglass on there to ad a bit of spring to it. no guides from me unfortunately.

Why not just leave it thicker. - my bow isn't much over 5' and that includes a hefty knot. I just left it a bit thicker at the ends and it pulls at least 55lbs at 30" - probably more like 60lbs actually.
I'm looking forward to shooting it in the summer.

Can anyone suggest a supplier for a string with only one loop?

 

[caliban]

Hi Durulz! The redish coloured bow in this pic is around five feet long and is backed with a double layer of silk. It's easy to back, I just wet the silk and stuck it on with slightly diluted wood glue, the cheap white kind. Just keep smoothing it to keep out the wrinkles. Epoxy would be better. The silk stops a short bow from splintering on the back. It's my understanding that silk and linen will make a bow stronger, but it will NOT increase the poundage.

I think the only two things that will up the poundage of your bow would be fibreglass or sinew I've never tried either, but you can buy glass drywall tape from B&Q and just epoxy it on. I've processed sinew, and to be honest, it's not that difficult if you can get a butcher to give you some deer or beef sinew in the first place. I've heard that it works best on a short bow with a bit of reflex built in. You stick it on with gelatin, or hide glue. You can add a fair bit of poundage to some woods by heattreating the belly with a hot air gun, don't know of Yew is one of the woods that takes a heat treat though. Try paleoplanet archery forum mate.

"Can anyone suggest a supplier for a string with only one loop?"

Richard Head Longbows, £13.00. You can twist your own without a jig, but it's a right PITA, getting the single loop is the easy part believie it or not.

 

[Mahikan]

I am lucky and live in Canada where I hunt and trap so have a ready supply of rawhide and sinew to back the bows I make.
However when you find yourself short of an animal or two to harvest for these products what I teach my Bushcraft Courses is to use Rawhide chews for your pet dog.
Some of these chews are quite large and come in more or less a role of rawhide.
These I soak in water till they are soft, dry them in a cloth and cut them to fit the back of your bow.
Then put the cut strips into a bowl filled with white carpenters glue, I prefer 'Elmers Glue" though I am not too sure if you get that in the UK.
Once the Rawhide has soaked up a ton of this glue put them on the Bow and lightly bind them in place with twine. When nearly dry remove the twine it helps if the glue is still slightly tacky so you can remove the twine easily, once fully dry trim the Raw Hide. I have found I can add two to three pounds of pull to the Bow using this method.

In Canada the legal hunting pull weight for a Bow is 45 pounds at 28", with this weight I can down a deer or Elk or even Moose so long as I have the correct arrow weight, so don't be too keen to put too much pull weight when tillering your bow.
Hope that helps you out or even sets you in a new direction.

 

[Bardster]

can't say I have heard of that but I suppose it could work. - I know you can put some fibreglass on there to ad a bit of spring to it. no guides from me unfortunately.

Why not just leave it thicker. - my bow isn't much over 5' and that includes a hefty knot. I just left it a bit thicker at the ends and it pulls at least 55lbs at 30" - probably more like 60lbs actually.
I'm looking forward to shooting it in the summer.

Can anyone suggest a supplier for a string with only one loop?

Its easy to twist your own, just need a clamp/bulldog clip. The jig in this link is not entirely necessary but works well. (all it does is give you the right lengths)
http://www.stickbow.com/stickbow/features/flemishstring/flemishstring.html

 

[caliban]

Mahikan, got any pictures of your bows? They sound cool. Personally I'd just leave a stave like the one described a bit wider and flatter, maybe an eliptical cross section to retain maximum heartwood and increase the width, and up the oomph, but I'm by no means a bowyer LOL!

 

[Mahikan]

No I'm afraid not, taking pictures is ok but how the hell you get them on this computer thing is outside of my techno ability. I'll see if I can get some techno direction from my Wife!

I agree with making extra wide Bows, as you described, with the woods I get locally its sometimes the only thing I can do to make a decent bow.
My Bows are generally copies of local native bows, Cree, Blackfoot they tended to be quite short around 4-5ft and normally they were backed with sinew. Most often the Back strap sinew from large ungulates (deer family).

 

[Everything Mac]

I am amazed that there is a limit to power for hunting. I certainly wouldn't have thought it would be 45lbs at 28"

Bardster - cheers for the link mate but I would rather just buy a ready made string than faff about making my own (they both involve buying stuff and making a string is added hassle.)


andy

 

[caliban]

"I am amazed that there is a limit to power for hunting. I certainly wouldn't have thought it would be 45lbs at 28"

I think that's the minimum poundage for hunting. It's based on the power needed to take a deer at fifteen yards with a sharp broadhead. I think the hunting competence test consists of hitting a five inch paper plate five times at fifteen yards, with your chosen hunting bow. I think most hunters use higher poundage, between 45lb and 70lb. I'm sure that it was the great Howard Hill's opinion that a well tuned 40lb bow with matched arrows of the correct weight and tip, could kill any animal on the American continent, including the Grizzly.

 

[Bardster]

I am amazed that there is a limit to power for hunting. I certainly wouldn't have thought it would be 45lbs at 28"

Bardster - cheers for the link mate but I would rather just buy a ready made string than faff about making my own (they both involve buying stuff and making a string is added hassle.)


andy

Drop me a PM with the length you need and I'll make you one over the weekend if you like.

 

[Mahikan]

Yep you are correct thats the minimum limit.

My compound bow is 70 pound and my recurve crossbow is 175 pound!

Generally an arrow with a 100 grain broad head is used going up to 200 grains for bigger beasts.

 

[wattsy]

i reckon its probably a minimum rather than a maximum

 

[C_Claycomb]

As has been said, linen won't raise the poundage, but will protect the back from breaking. If you have followed a single ring (I think that with thin ringed yew this is not as critical as with ash) on the back, it should be fairly safe to start with. Linen backing, be it cloth or lots of parallel cords is at its best when you have to work with less than perfect board staves where the wood fibre runs out of the back surface.

Linen glues on just fine with the weatherproof version of Evostik wood glue.


For upping the poundage you need something that is going to do some work. Linen does not stretch, but silk and even nylon do. Have you considered doing a cable backing? The tiller might need to be tweaked (limb tips need to be stiffer than a normal bow to compensate for the strength of the cable pulling the bow into a different shape)
http://paleoplanet69529.yuku.com/topic/19738

Yew is one of the woods that responds well to a sinew backing, and that will definitely up the poundage. Its not something I have ever tried though. A shortage of sinew and a surfeit of long ash and hickory staves meant I never experimented that way.

 

[durulz]

Cheers so far guys.
I decided to put the linen on the back because I have made a big fluff whilst carving the stave:
I cut a chunk of the sap wood out!
Doh!
So I decided to make a yew flat bow. Fearing tha absence of the sap wood would weaken it I thought I'd put a back on it to give it strength, but thought it may also up the poundage.
I did read that nylon was good to use, since it does have some flex.
So that's what I'll do - use nylon cord.
Are you sure epoxy is OK? I would have thought it was too brittle and would splinter when bent.
Again, any and all advice is gratefully accepted.

 

[C_Claycomb]

Rather you than me trying to use epoxy to stick nylon cords to the back of a bow!

Complete glued down coverage of the back with cloth or many parallel cords = safety
Single cord, not glued = poundage

Cracking glue is also a function of the thickness of your glue line. If you used nylon cloth and had a thin glue line, it could well flex very well. Epoxy is used for laminated bows, after all. Globbed on epoxy used to hold down lots of wayward nylon strings...that would be more likely to crack. You need a long cure epoxy to give you time to work, and I would expect that you would need to take a lot of care on how thick it was.

Working time is why the PVA wood glues are so nice, they are water based and take plenty of time to dry.

Looking forward to seeing the finished result.

Oh, one other thing. You can make a yew bow from 100% heart wood. You don't absolutely need the sap wood. If the back is otherwise in good condition, but for the lack of sapwood, you may be fine as is.

 

[durulz]

Hmm...I didn't like the sound of epoxy.
Good old PVA is much easier to work with.
OK, so am I right in saying that if I back it with linen, glued on with PVA, that will make it safer and less likely to break?
Also, some some use linen thread, some say linen strips. Which is best? Is it just a case of gluing on strips of linen? And if so, how many?

To be honest, I'm treating this first bow as an experiment. I cut two lengths of yew - the first was slightly shorter (the one I'm using now) and the second was about 6 feet in length. I'm leaving that one until I've finished the first bow so I can learn from any mistakes. Therefore, I'm keen and happy to experiment and see how to do things before embarking on the second bow.

Once again, cheers for all advice.

 

[Mahikan]

Ok!!
I have reached for my Bowyers Bible to extract some information for you.
One thing I presume you are doing is using Linen Fibres twisted into fine yarn that will be laid on the back of the bow side by side until you cover the back of the bow.

If this is the case the Bowyers Bible recommends hide glue, here we can buy that commercially at shops that make products for traditional carpentry, sometimes I make it. However white carpenters glue should work.

Nylon of the same thickness used in Backpacks can also be used though is not as good as sinew or rawhide. White glue can be used here though the Bible says it is not too good for backs that have had a growth ring comprised/damaged in the tillering process.

Another option is for you take the back down to the next growth ring.

I am sitting at home most of the day so I can access any info you may need from my Bowyers Bible.

Dave
www.mahikan.ca

 

[Mahikan]

A follow up to my last piece of info.
Nylon; can be used in sheets so long as it is the same weight, as mentioned before, as the material used in a backpack. The white glue should be thinned to make it quite runny so it will penetrate the fabric. Be sure to spread some glue onto the back of the bow before you lay your fabric on it, this will prime the surface that generally I scrub lightly with soap and water first, to remove any grease build up that may be there.
Still cant fine any reference to linen cloth being used as a backing fabric, so presumably the only way to work with linen is to buy rolls of linen twine.
If you do have a fault or low point in the back of your Bow it is most import to bind the backing material quite tightly in this area while the glue is drying.

You could bind the area that has a fault in it completely, around the circumference, with the same material you use to back the bow. Then put the backing on the bow. This was done a lot by First Nations people over here, though of course they were using sinew or rawhide.

Dave
www.mahikan.ca

 

[C_Claycomb]

I read the Bowyer's Bibles and was inspired to try linen cloth on two rather questionable hickory board bows. Obviously the very best arrangement would be to use long staple raw flax fibres, they would all be arranged so that they carried load lengthways and would make a fairly smooth finish.

Linen fabric is less good because you have about half the weight/volume of fibres running across the back of the bow were they won't be doing any work at all. However, linen fabric was what I had and I have yet to find anywhere to get raw flax of decent length. I think Tim Baker probably grew his own

My fabric backed bows took some set (my bad, and the hickory probably wasn't as dry as it should have been) but they didn't break up which I suspect they would have if left nude