Do we have to stretch our strings?

[ajbruggink]

Hey guys,

I'm still a newbie but I've been making endless strings for my bows for almost 2 years now after learning how from TBB vol. 2 but I've never stretched a B-55 Polyester (basically the same thing as B-50 Dacron) string after making one, I just put it on the bow and shot it. Is this wrong? Should I be stretching my strings to some percentage of their breaking strength before use? I heard about it first when I read up on how to make a bowstring out of silk, this particular source recommended stretching it to 90% of its breaking strength. I don't notice the brace height on my bows changing over time. The only attempt I ever made at stretching a string was when I tried to make a string out of Fastflight for one of my bows. I made it 68" long for a 72" long bow and it still gave my bow a brace height of 8 1/2". So I tried stretching it by hanging it from a hook on the rafter of my basement ceiling and zip-tying weight-lifting weights to the other loop. After a week of trial, the most I could get it to stretch was 3/4". If 90% of the strength of that Fastflight string was needed, I didn't have enough weights for it anyway because I used 8 strands, giving it a breaking strength of 400 lbs, this is taken from a belief that a strand of Fastflight has a breaking strength of 50 lbs, I say belief because I have never tested the breaking strength of a strand of Fastflight, only linen. If I should be stretching strings, how do you do it? Any info, advice, critiques, etc are greatly appreciated.

Thank you,

Aaron

[Del the cat]

If it's going to stretch, it will stretch, you can then adjust it (by twisting it up or re-tieing the knot.)
Some people will pre-stretch the string material or string, but I've never bothered... mind I now use a higher grade string with less stretch... generically called FastFlite, but the actual one I use is AstroFlite (a choice based on cost!)
Del

[DC]

If it's going to stretch, it will stretch, you can then adjust it (by twisting it up or re-tieing the knot.)
Some people will pre-stretch the string material or string, but I've never bothered... mind I now use a higher grade string with less stretch... generically called FastFlite, but the actual one I use is AstroFlite (a choice based on cost!)
Del

+1

[George Tsoukalas]

After I make the B 50 string, I set the brace height and measure it.  I leave the bow strung. Then I keep checking and give the Flemish string a few twists id needed. Then I string it and repeat and until the brace height stays constant.

Then I go ahead and and serve it.  The serving gets may get unraveled and look funky unlesste string is done stretching.

I used to tie continuous strings and I believe they were less prone to stretching. I don;t remember for sure.

Jawge

[osage outlaw]

I don't think endless loop strings stretch as much as twisted strings do.  If you are making a heavy duty endless loop string you probably won't see much stretch.  I used to make endless loop strings when I first started in bow making.  Once I learned how to make a flemish twist that is all I have made since.  I have a 2x4 with a couple heavy duty shelf brackets with bolt hooks that I can adjust up and down the board.  When I make a string I stretch it until I get the exact length I want from it.  That usually means I'm bending the shelf brackets due to all the tension.  It is much more than when the string is on the bow.  It squeezes out the extra wax.  I take a piece of leather and run it back and forth to heat in the wax. I leave it stretched over night.  When I put a new string on a bow there is zero stretch.   

[Mo_coon-catcher]

I always prestretch ther string. It's probably not truly needed but after I stretch it it never moves. I usually stretch by running a large dowel through each loop. I hold one and put the other under my feet and use my leg strength to stretch it. With a Flemish twist with D97 I usually get about 1" of stretch and with B50 I get about 2". With te dynema once the initial stretch is over I can barely budge it. With the Dacron I can usually get about 1" of rubbery stretch that goes back as soon as I relax. So I figure in that amount of stretch when I twist them up. The dynema is where it is with length and the Dacron stretches a little at brace. But at that point they are both consistent.

Kyle

[loon]

I'd hang a weight that's 80% of breaking strength from one end if it's Dacron? Also for rawhide and silk. Probably not needed for plant fibers and low stretch synthetics

[Stick Bender]

I just made a endless loop string 7 strand 2 ply it stretched after the first 100 arrows & readjusted it has stayed put since

[Pat B]

After I make a string I wax it well and hook a loop on a hook and stretch the string while rubbing it vigorously with a small piece of leather. This will heat up the string allowing the wax to sink into it plus it helps to stretch the string. When I brace the bow with a new string I'll lay the bow across my knees  and push down on the tips, also stretching the string. This is usually enough to get most of the stretch out. I do use a Flemish twist string and not an endless loop.

[ajbruggink]

Thanks for the replies, guys. So it seems the consensus is for endless strings it doesn't matter much but for Flemish twist it might. I make endless strings because I just don't get how to make Flemish twist strings, but I'm not going to make excuses, one day I will make a Flemish Twist string when I actually invest real time into it and accept the fact that I probably won't be successful at first.

[Pat B]

I believe there is lots of info about Flemish twist strings on YouTube. Check it out.

[loon]

Dacron is always going to creep... unless the strands are pre-stretched or something

[Lehtis]

Remember, if you are going to compete in IFAA“s historical bow class, Dacron is in principle the only material allowed and Fast Flight or other modern fibers are not allowed. Also, as funny as it sounds, all traditional fibers are excluded by IFAA rules. For hunting, back yard shooting etc., you can use any string material you like.

[Lumberman]

Thanks for the post and info!