Primitive Archer
Main Discussion Area => Bows => Topic started by: Black Moshannon on November 20, 2019, 02:08:44 pm
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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?
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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.
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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.
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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.
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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.
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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.
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Lose the timber hitch and go with two loops.
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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
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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.
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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#
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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.
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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?
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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.
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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.
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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.
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All of the above! I don't have experience with linen, but if you keep it waxed and reenforce the loop/knot area it should fairly durable.
Hawkdancer
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I found getting them good and wet Pryor to stringing adds strength . Old flight trick they have been using for years. Arvin
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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.
That is a bummer about the linen thread breaking. The Barbour Pure Flax Sinew with “Soft” on the label is about 30-35% weaker than the standard linen thread. The soft version is made with shorter brushed fibers. A good roll of Barbour 5-cord will have a breaking strength of about 35 pounds. A exceptional roll will break at 40 pounds. The breaking strength also changes quite a bit depending on humidity levels. It becomes much more brittle in very low humidity.
Alan
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This is the loop I have been using for around 5 years now?...Very durable... It starts as a 16 continuous strand using 7 ply wrapped and soaked in hide glue at the loops...Then cut 8 strands away...See "strings" in Bowyers Bible for instructions...
Don
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That looks like a better string that the ones i'm making, which are standard Flemish twist.
Alan, the stuff I bought is five cord and broke at just over twenty pounds. Ill have to see where I can get Barbour linen that is not soft. Hopefully this company carries it. So far my strings have held up.
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Black Moshannon,
This string was also soaked in a very thin hide glue solution before stringing and then allowed to dry strung for a few hours in the AC...Water and a few crystals of hide glue mixed into a lite syrup, very lite...I usually get hundreds of shots and change out every hunting season to a new string...The bowyers knot that I tried early on would break quickly, seems it would cut itself or at least fail in that area...Once I went to a carefully made continuous string with proper even tension on each strand I had no problems...
Don
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Thanks for the tips, Don. Hoping mine will last at least one year. I may try the hide glue.