Help with Bowstrings

[Tommy D]

Hi - I am making my first bow - a yew flatbow and am at the tillering stage. As I live in East Africa I cant get bowstring Dacron very easily but I do have 135 lb braid Dacron fishing line - will 6 strands of this twisted together work and be strong enough (60 lb bow)

Thanks

[Hillbilly]

If it actually tests at 135 lbs, two strands would theoretically be strong enough, but might not be big enough to shoot comfortably. 4 times the draw weight of the bow is usually a good safe string strength, but I always overbuild mine, partly for insurance, partly to get a fat enough string to fit the arrow nocks.

[Tommy D]

Thanks HillBilly,

So 4 strands would constitute "overbuilt" enough?

[adb]

Make the string so it's just under 1/8" diameter, then your arrow nocks will fit. More strands are better than less.

[markinengland]

More strands are not in my opinion better than less.
A bow sring needs to be strong enough, and four times bow weight is enough. Going up to 8 times bow strength surely is the reasonable limit if this ensures that each side of the loop is strong enough?
The string can be built up as necessary in the central serving or arrow nocking area and at the ends, but what possible advantage would there be in having a 16 strand string on a 60lb bow that is safe for a 540LB bow?
I think this is where the fallacy that fastflight breaks bows comes from. Yes, if you make one strong enough to pull an ocean liner it may shock the bow, but make it strong enough for the bow (and not a lot more) and there should be no problem.
Mark in England campaigning for skinny strings!

[adb]

Why run the risk of a broken string, and more than likely a broken bow, just for a smaller string... and perhaps 2 fps more arrow speed? For me, string diameter is more important than "overbulilt" strings. Does it matter that the string is rated way higher than the bow's weight? 
Skinny strings are uncomfortable to shoot.

[markinengland]

ADB,
I think of it this way.
If you jump of a four foot wall with bent knees your legs can absorb the gradual impact (like a realistic strength string).
Jump off a three foot wall with dead straight legs and you will break your legs, maybe your hips and possibly even your neck. The sudden impact is deadly.
I saw a kid do this once and he broke both femurs. Not nice!
Shooting a bow with a four times draw weight string is proven to be safe.
Way overbuilt strings, especially fron none stretch materials are just too strong and out of balance with the bow. The shock is not absorbed within the string, but within the bow.
Why risk the bow from a string that is too strong or too weak when you can make it safely just about right? if this means you build the serving area  up to fit the arrow nock this is not hard to do. If this means a string last one year instead of two so what? Make a new string!
Mark in England

[Tommy D]

I am watching this thread develop with interest - liking Marcs idea about skinny strings more - but only because I wont have to use more than 24 feet of my precious dacron fishing line!

Does everyone aggree 4 strands of 135 lb dacron wont break in a 60 lb bow?

Thanks for all your responses

[Hillbilly]

It shouldn't break, but it may saw the tips of your bow off.

[markinengland]

Has anyone actually seen a bow string saw the end off a bow?
I made a two strand string once that almost cut my fingers off but the bow seemed OK. It was a little 22 inch bamboo bow pulling a ridiculous weight at 6 inches that shot an little bamboo arrow over 100 yards. I was so thrilled I almost forgot my fingers (but remembered to pick them up before getting the arrow!)
If I make a skinny flemish twist string I build the ends up, and the nokcing point as well if I think it necessary. I used to do the same with endless loop strings. Partly this is because I am stingey and try to get value for money from my string material! I don't mind a loose fit on the string. I prefer a loose fit to a tight one. My primiitve arrows have a very open nock and loose fit and they work great.
Mark in England

[adb]

Good grief. String material is cheap, compared to a broken bow. Also, Mark, my point all along. Skinny strings are uncomfortable to shoot. 14, 16, or even 18 strands. Cheap. A large spool of B50 or FF is cheap.
No, I have not seen or heard of a string "sawing off" the end of a bow. But I have seen a few strings with broken bundles at the nocks. Thankfully, they weren't 2 strand strings, and didn't break. There's a lot better places to be "stingey" than with string material.
Hey, Tommy D... give me your address in Africa, and I'll mail you a spool of B50. No, really, I'm serious. Mark... you want some too? Then you can stop picking up your fingers.

[sailordad]

ok im getting close to needing a bow string or seven( really by end of summer itll be 7 ). to cheap to keep buying them. so where does a guy go to buy a large spool of this b50? i have already found  a couple of string build a longs so all i need is something to turn into bow strings.


thanks in advance.


                                                                              tim
         

[Hillbilly]

Sailordad, Three Rivers sells B-50-good price, good service. Mark, I've heard several people (including people who make bows commercially) say that they have damaged the tips of their bows with skinny FastFlight strings. Haven't experienced it myself because I don't use it, why take chances. If I'm using synthetic string, I like 14 strands of B50. Feels good, shoots good. Every time I have tried skinny B-50 strings, I also have had a problem with the timber hitch slipping.

[markinengland]

ADB,
In my opinion an bow can be broken by an overbuilt string. Here many bowyers have said that their longbows are not suited to fastflight strings. Why? Because overbuilt strings were  made to fit the arrow nock and just didn't stretch at all, strings were too strong, strings broke bows.
The point I am trying to make and maybe failing to make is that a string needs to be strong enough, it needs a reasonable safety factor but that a string can be TOO strong. If I aim to make as bow as good as I can. to perform as well as I can well within safety limits, if I do the same with my arrows, why not with the string also?
With modern string materials an 8 strand string can still be within safety limits or actually twice as strong as it needs to be if using the four times bow strength guideline. A 16 strand string may be too strong but if flemish twisted it may have enough give in it to avoid overstressing the bow.
The string can be built to be a good match for the bow. It needs thought or design as much as the bow does. Material used, form of construction, number of strands, how the ends are built up, how much twist is put in, how the knocking area is matched to the size of your nocks can all be intelligent choices. The choice of string should not, in my opinion be limited to how many strands is needed to fit your nocks. This seems somewhat crude. The string is an important and often overlooked element of the bow.
I have enjoyed the experiments I have carried out with string making. The only string I have broken was my first linen string where I didn't build the ends up enough. This broke on being strung. My second line string lasted almost two years of weekend shooting before being retired for a new lighter linen string. My two strand string was done for a laugh on a bow that was made for a laugh. Please note that the two strand string did not break! It sang a high note but is still going strong.
I don't much like B50 myself. A string made of this stretches so much when first strung it is hard to make them the right length. The string stretches on the bow so bracing is harder and stresses the bow more. The string stretches on the shot. I like linen and BYC450plus because they don't stretch so much.
I have made very skinny strings with a bowyers knot that don't slip. It took me a little while to get to grips with this knot and find a way that works for me. They really do "weld" themselves solid and don't move at all once bedded in.
Mark in England

[adb]

Mark,
RUBBISH!!! A bow will not break by an overbuilt string. I've not heard anything so ridiculous in a while. If your bows are breaking, it's not from the string being "overbuilt." Yes, the string needs to match the bow, and a 14-18 strand B50 string will be good for just about any bow. Fastflight is excellent non-stretch string material, so is B50. If your B50 strings are stretching that much, I believe it is probably the fault of the string maker. I have not had any problems with B50. It's excellent, also, and makes suitable strings for ANY bow.
Seems to me that you're making mountains out of mole hills. Skinny strings are uncomfortable to shoot. Period. The skinnier the string, the more it WILL stretch.