I"ve decided to try my hand at string making. I bought  the dvd How to build a great bowstring. I made a flemish string jig with the dimensions from the dvd. The board is marked with actual string length. So far both strings i've made have come up two inches shorter than they were suppose to. Don't know if I'm doing it wrong or if they just need to be stretched.
I am using dacron B-50, 14 strand, two bundle. I did stretch one by hanging about 150 lbs. from it. And ironically it stretched to the length I wanted. Seems to be shooting fine and has not creeped back in length.  How much stretch is normal?

B50 does stretch, if you got it to the length you want it is all good.
Most boards give you an estimate of length that can be adjusted by the loop tails that you twist after you do the loop. Lets say you made a loop that is 3" s giving you a loop of 1.5". You used 8" as your start point and it Gives you 5" to play with. Say your bow pulls 50# you can make a test string add 75# of weights measure how much it stretches then make your real string by subtacting that much from the 8" you started with.

I know someone who uses a come along to stretch all the stretch out of his string overnight.

I use B 50 too. I like 1-2 twists per inch. I don't serve until it stops stretching. Jawge

i prefer endless loop strings.
i pre- stretch before i make up the string.
then i get the length just right.

I use B-50 and a Flemish twist with a bowyers knot on the bottom limb. I pre-stretch my strings while making them then again once they are on the bow. If they stretch too much I just re-tie the bowyers knot so the string fits right.

Thanks everyone, gonna play a little with loop size and length of where I start my braid
Besides I can always make a bow to match the string

Most Flemish twist strings I see (probably 95-98%) are twisted up in a counter-clockwise fashion. But the individual strands themselves have a clockwise twist. So guess what happens when you put some pressure on your new string? Yep, the strands have to unwind along with the stretching causing added length.

I use a clockwise twist for all my strings and only get an inch of stretch using B-50/55 material. And that's with a 12 strand string..........Art

Here we go again:) Art yer lucky ifin ya know what CW and CCW even are at your ripe age...    

haha anyone else get a kick out of the old guys hassling each other?

You and me are goin' to have to shoot bows&arrows at 20 paces one of these here days Ol' Boy!          :D

Yer on Ole Timer, yer on.. I'll even hold your cane for ya while ya shoot...  

       

That's alright Roy Bub, I have one on those canes that "stands alone". So take your best shot  

Well then kin ya hold my beer while I shoot? Don't wanna see it get knocked over ya know:) I'll pack a lunch for ya cause yer gonna need it ole timer:)

Pack a good on' Roy-Bob, cause I do like to eat. Oh, and bring a six-pack, and we'll forget about the shoot-off and just have a picnic!  

Grumpy old men.      
Dave.

I think maybe Roy and Art need some alone time  

Ya got a deal ole timer:)

Great! You got wine too!