Primitive Archer

Main Discussion Area => Bows => Topic started by: DC on October 15, 2016, 03:40:56 pm

Title: Breaking string
Post by: DC on October 15, 2016, 03:40:56 pm
As far as damage to the bow is concerned is there any difference between a dry fire and a broken string? I'm thinking off making a gut string and wondering how brave I can be. ???
Title: Re: Breaking string
Post by: sleek on October 15, 2016, 05:32:53 pm
Every string I have broken was on release, the energy was already in the arrow when it broke. Id crap my pants if it broke at full draw.
Title: Re: Breaking string
Post by: RatherBinTheWoods on October 15, 2016, 07:16:35 pm
I'd try on a bow you don't mind losing first! I want to try a rawhide one someday but have the same worries.
Title: Re: Breaking string
Post by: Dakota Kid on October 15, 2016, 07:44:40 pm
Practice making cordage for a bit before you throw one on your bow. You can hang them from a branch and add weight to the end to test the strength. I never string a bow with a handmade string unless it will lift the (draw weight x 1.5) without breaking.  I typically leave the weight hanging from the string overnight too. It helps to pre-stretch them.
Title: Re: Breaking string
Post by: DC on October 15, 2016, 07:55:56 pm
One of the reasons I'm thinking of gut is because there is little or no "cordage" to them. The strands are one piece and you just put 3 or 4 together and twist them up and stretch them out. You don't have to worry about introducing short lengths while you're twisting. I haven't sorted the loops yet, that may take a little cordage knowledge. If you do a google on "gut bowstrings" you'll see the video I'm following so far. It seems to be the only one there is, strange.
Title: Re: Breaking string
Post by: Pat B on October 15, 2016, 08:18:32 pm
There may be a difference because a dry fire goes to brace height and a broken string goes past unbraced but both could e devistating to a bow.
Title: Re: Breaking string
Post by: PatM on October 15, 2016, 08:42:56 pm
In the past yew bows were known for breaking on the belly side when a string broke.

  Remember that all gut is not created equal. The gut that tennis strings are made with is a very specific sinew like portion of the gut. It's not just strips of sausage casing.
Title: Re: Breaking string
Post by: Marc St Louis on October 15, 2016, 08:53:17 pm
I picked up a couple rolls of tennis racket gut a few years ago, never got around to trying it.  I did make some gut strings from sausage casing gut a long time ago, they weren't too bad
Title: Re: Breaking string
Post by: sleek on October 15, 2016, 08:59:54 pm
Dakota Kid, your strings should be at least 6 times the poundage of the bow. I make them 8.
Title: Re: Breaking string
Post by: DC on October 15, 2016, 09:10:33 pm
So far I'm just playing with pork sausage casings. I've twisted some and they are drying. I'll figure a way to do some strength testing without breaking my scale.
Title: Re: Breaking string
Post by: mullet on October 15, 2016, 11:12:08 pm
Rattlesnake skins and squirrel skins are very tough.
Title: Re: Breaking string
Post by: loon on October 15, 2016, 11:17:40 pm
In the past yew bows were known for breaking on the belly side when a string broke.
I think my horn bow acquired a crack perpendicular to the limbs when this happened. So far I put loctite 480 on it and it's held up...
https://www.youtube.com/watch?v=tLFEU139Sms
Title: Re: Breaking string
Post by: mikekeswick on October 16, 2016, 04:11:01 am
3 or 4 times the strength of the bow for string strength is plenty.
don't just make your actual string. Make plenty of test pieces, get a scale and break them. Only one way to know that it is strong enough and you are doing your job. I second making lots of cordage of all types to get a proper grasp of what you are doing.
Title: Re: Breaking string
Post by: BowEd on October 16, 2016, 07:24:10 pm
loon..were you using fast flight string?
Title: Re: Breaking string
Post by: Dakota Kid on October 16, 2016, 08:38:12 pm
Dakota Kid, your strings should be at least 6 times the poundage of the bow. I make them 8.

Unfortunately I have no way to hang 300+ lbs from my strings.  :laugh: The bucket I use only holds 4 bags of lead shot.

I suppose I knew that it should be heavier from using store bought string of a known poundage. I've only made a couple natural material strings, 1 sinew and 1 retted tulip poplar bark. It's quite a time consuming process. I just basically wanted to know how to do it if the need ever arose.
Title: Re: Breaking string
Post by: loon on October 17, 2016, 01:07:12 pm
loon..were you using fast flight string?
yes, something like that..
Maybe I should make a dacron string now that I think about it, although I glued the notch back on and filed the notches deeper so the force actually goes through the wood
Title: Re: Breaking string
Post by: loon on October 23, 2016, 04:48:25 am
So far I'm just playing with pork sausage casings. I've twisted some and they are drying. I'll figure a way to do some strength testing without breaking my scale.
Very interested in this! Apparently Magyars might have used gut strings for their hornbows?... ...
Title: Re: Breaking string
Post by: Marc St Louis on October 23, 2016, 08:12:47 pm
You should look into tennis racket gut, it is quite strong for its diameter.  The stuff I picked up was from a source south of the border and I think the shipping cost as much as the gut