Linen string break

[Black Moshannon]

I had a new linen string break today at release. It broke at the timber hitch knot on the bottom nock. The bow is a 66" 58 pound black locust D bow with 1 inch of string follow. This is my first time using linen for bowstrings, previously I used Dacron B-50... I always made a flemish twist string with the loop on the top nock and just used a timber hitch on the bottom, which is what I did with the linen. The linen is 7 strand from pyrosupplies and had six plies in the string. The string lasted a few shooting sessions. I'm thinking I will have to make a regular flemish twist loop at the bottom nock as well, and perhaps use 8 plies in the string. The string is listed as having a strength of 48 pounds. I ordered some 38 pound six strand string from Pyrosuppies which is supposed to be higher quality, according to the website. I am also going to try to find a source of Barbour linen thread, which I heard is best quality. Anyone have any thoughts on the timber hitch knot and flax thread?

[Eric Garza]

String from Pyrosupplies used to be good. Not so much anymore. The last batch I bought from them was too inconsistent to use to make bow strings.

[Black Moshannon]

I found out that Coats now makes Barbour linen string. So far the only places Ive found are big shoe or leather supply companies that do not give a price online but will give a quote.

[Black Moshannon]

Cambell-Randall Machinery in Texas sells Coats/Barbours linen thread in many different strand counts. I ordered a one pound spool of five strand. Hopefully it’s the answer.

[Badger]

  You will find the actual strength is exactly 1/2 of what they show it as. This is because they test it as a single loop as are actually testing two strands. I have to use 8 strands on my 50# flight bows and that won't give me too many shots.

[Black Moshannon]

Is that 8 strands of the 7 strand stuff? That means my strings going to be thicker. I’ll make a Flemish twist loop on both ends of the better quality for my #50 bow and wait for the Irish stuff to arrive for my 58 and 60 pound bows.

[PatM]

 Lose the timber hitch and go with two loops.

[Marc St Louis]

I don't bother using pyro linen for anything but kids bows.  I picked up a # of high quality linen through ebay a few years ago.  A 300# string is not much more than 1/8" thick

[Black Moshannon]

Thanks for the suggestions. I'll wait for the Coats/Barbour linen to come in, then break test it and make a regular flemish twist string with the right number of plies. I'll leave a review here. This linen came to $61 with shipping... expensive but worth it if it's going to work.

[bownarra]

And (it is very important!) add a few strands extra at the knot to counter the weakening effect of the knot. At least then it won't be the knots fault Pretty much any knot weakens cordage by 30% - factor that in and the knot won't be a problem.
Of course you should test your linens breaking strain before making a string and use 5/6 times safety margin. 58# bow x 6 = 348#

[redhillwoods]

I've made about 80 linen bowstrings all with the Irish shoemakers' weave. I get the spools from a company that makes it primarily for the funeral home industry (tying orifices closed). I've stress tested the strands at about 6lbs. each and just overshoot the draw weight a bit for insurance. So for a 40lb bow I would use 8 strands. I make the endless loop style and I've never had an issue with breakage.

[Marc St Louis]

I've made about 80 linen bowstrings all with the Irish shoemakers' weave. I get the spools from a company that makes it primarily for the funeral home industry (tying orifices closed). I've stress tested the strands at about 6lbs. each and just overshoot the draw weight a bit for insurance. So for a 40lb bow I would use 8 strands. I make the endless loop style and I've never had an issue with breakage.

?.  Are you saying that you make a 48# string for a 40# bow?

[Badger]

I've made about 80 linen bowstrings all with the Irish shoemakers' weave. I get the spools from a company that makes it primarily for the funeral home industry (tying orifices closed). I've stress tested the strands at about 6lbs. each and just overshoot the draw weight a bit for insurance. So for a 40lb bow I would use 8 strands. I make the endless loop style and I've never had an issue with breakage.

   You would need a minimum of 160# for a 40# bow or it would break just after a few shots. A 48# string would not survive being braced?? I would rethink your formula.  I make hundreds of linen strings so I know a little about it.

[Black Moshannon]

The linen arrived, it’s packaged with the Barbours red hand trademark box saying “This brand the best and the best now”. Its 5 cord and soft, and broke at just over twenty pounds. I made a Flemish twist string with ten plies for a fifty pound red elm D bow. So far it looks and shoots great. With the serving, the string just comfortably fits the self nocks of my 11/32 diameter arrows. My serving is Brownells nylon. In order to make a 12 ply string for my sixty pound bows, I am getting some thinner sewing thread for use as serving.

[Black Moshannon]

Iv'e made several strings from the Barbour linen and have been shooting for a few weeks and no problems. Anyone know how long to expect these strings to last? I used to shoot the B-50 for like eight years without any failures although I shouldn't have. I know these strings take more care and need replaced more often but not sure how often. I am using straight beeswax on them. Also wondering if I should count my shots to see how much wear I'm putting on them.