Primitive Archer

Main Discussion Area => Bows => Topic started by: jeffp51 on December 09, 2015, 11:05:57 pm

Title: spectra bowstrings
Post by: jeffp51 on December 09, 2015, 11:05:57 pm
Just made a bowstring from 65lb Powerpro (spectra) fishing line, as I was told it is the same as fast flight.  I definitely like the lack of stretch compared to B-50, but I am still working out thicknesses.  I used 12 strands and padded the loops with b-50.  However--after serving the middle it was still too thin for my arrow nocks.  Double serving the nock resulted in too much thickness--my arrows are now too snug.

Am I okay with 10 strands for a 55 lb bow? 
How many strands and how long should I make my loop padding?
The string Mike Roberts in England made for me for my trade bow is a work of art in itself.  Mine are serviceable at best.  What is the secret to clean, pretty bowstrings?
Title: Re: spectra bowstrings
Post by: BowEd on December 10, 2015, 12:25:38 am
Try a breaking test of one strand.
Title: Re: spectra bowstrings
Post by: PatM on December 10, 2015, 07:39:27 am
You are better off making this material into an endless string and using a thicker serving material.
Title: Re: spectra bowstrings
Post by: BowEd on December 10, 2015, 08:33:18 am
Also serving can come in different diameters too.Which you may know.I use .018 thickness.I triple serv the area where my arrow nock goes and my fingers touch.That fits my self nocks perfect,but not those plastic arrow nocks though which I never use anyway.The little round file I use for the nock in arrow shaft making is just right for that and matches the diameter of my serving.You will have to experiment with it to get it right.
Title: Re: spectra bowstrings
Post by: JoJoDapyro on December 10, 2015, 10:46:08 am
No Photos? What is the line strength?
Title: Re: spectra bowstrings
Post by: PEARL DRUMS on December 10, 2015, 10:56:42 am
Bee's wax is the secret. 
Title: Re: spectra bowstrings
Post by: BowEd on December 10, 2015, 11:16:44 am
To getting it to fit tight Pearly?Beeswax?
Title: Re: spectra bowstrings
Post by: PEARL DRUMS on December 10, 2015, 11:25:31 am
Yes sir. Its keeps the bundles nice and hard.
Title: Re: spectra bowstrings
Post by: TimothyR on December 10, 2015, 11:39:29 am
Use an endless loop method and serve it with the same stuff.
Title: Re: spectra bowstrings
Post by: PatM on December 10, 2015, 12:31:16 pm
No Photos? What is the line strength?
65lb
Title: Re: spectra bowstrings
Post by: PEARL DRUMS on December 10, 2015, 12:40:34 pm
I question the cost savings. I think a guy will spend more on fishing line than a Sale spool of D97. Most no stretch fishing lines go for $15-25 for 125 yards. An average string requires about 16-18 yards of line.
Title: Re: spectra bowstrings
Post by: Aries on December 10, 2015, 12:51:15 pm
I'm a little embarassed I have been making endless loop style strings with artificial sinew exclusively since I began making bows 12+years ago. Do yall think this type of low stretch material in an endless loop style would maje any notable improvement in performance?
Title: Re: spectra bowstrings
Post by: PatM on December 10, 2015, 01:05:40 pm
I question the cost savings. I think a guy will spend more on fishing line than a Sale spool of D97. Most no stretch fishing lines go for $15-25 for 125 yards. An average string requires about 16-18 yards of line.
It's the availability for some guys.   Ordering and shipping for some guys is more of a hassle than just going to a local store and grabbing some spectra, particularly for those from non-archery areas.
Title: Re: spectra bowstrings
Post by: PatM on December 10, 2015, 01:08:12 pm
I'm a little embarassed I have been making endless loop style strings with artificial sinew exclusively since I began making bows 12+years ago. Do yall think this type of low stretch material in an endless loop style would maje any notable improvement in performance?
It will although by making an endless string already you are eliminating some of the bungee cord characteristics of stretchy material.
Title: Re: spectra bowstrings
Post by: Badger on December 10, 2015, 01:43:16 pm
I question the cost savings. I think a guy will spend more on fishing line than a Sale spool of D97. Most no stretch fishing lines go for $15-25 for 125 yards. An average string requires about 16-18 yards of line.
It's the availability for some guys.   Ordering and shipping for some guys is more of a hassle than just going to a local store and grabbing some spectra, particularly for those from non-archery areas.

   I think most of the gains from fast flight come from using a skinnier lighter string. I think it works out to be a gain of about 1 fps per strand of string removed. A lot of the tests done using fast flight are done with 8 strand strings.
Title: Re: spectra bowstrings
Post by: jeffp51 on December 10, 2015, 01:44:35 pm
every how-to I have seen on endless loop strings require a funky jig.  Is there a way to do this that I am missing?

I did in fact buy the fishing line out of convenience--and to test the stuff out. If it is 65 lb test, how do you calculate how many strands you need for a give bow weight?  10x the test strength?  If a bow is 50lb, then theoretically one 65# line would hold it at brace, although would not be strong enough to withstand the tension of an arrow shot, right?  Is there a TBB chapter on this?
Title: Re: spectra bowstrings
Post by: PatM on December 10, 2015, 02:16:49 pm
Make a less funky jig. It's not that hard.   You just need to establish length and a means to  spread the larger  loop of string to give room to serve the end loops.
 Plenty of recommendations as to the safety margin needed for bowstrings relative to bow weight and material being used.
Title: Re: spectra bowstrings
Post by: jeffp51 on December 11, 2015, 03:19:55 am
I'm a little embarassed I have been making endless loop style strings with artificial sinew exclusively since I began making bows 12+years ago. Do yall think this type of low stretch material in an endless loop style would maje any notable improvement in performance?

that is kind of what I want to experiment with. The TBBII chapter on string making says that a 20 grain reduction in mass will result in about 1fps improvement in cast.  If that is true--the B-50 string I made is 1380 grain, but the 10-strand spectra line I just made is only 612 grain.  I am a little dubious, but it suggests that I should see an improvement of about 38 fps over the other string.  I have no chronograph, but does anyone have experience to back that up?
Title: Re: spectra bowstrings
Post by: Pappy on December 11, 2015, 06:46:48 am
Not sure how much ,but assure you the performance is better with fast flight, less stretch/less arm slap and quieter  for a bonus.  :)
 Pappy
Title: Re: spectra bowstrings
Post by: BowEd on December 11, 2015, 07:10:51 am
Ditto...I can see the speed difference with the naked eye practically.The difference for me between 12 strands of B50 and 9 strands of fast flight plus was around 8 feet per second.That's a fact.Even with my sometimes mobile anchor....lol.
I agree with you Chris but he has to get his initial thickness of his serving first.
Title: Re: spectra bowstrings
Post by: Badger on December 11, 2015, 09:13:22 am
 Jeffrey, are you sure you weighed your strings right? Thats about 10 times what I would expect.
Title: Re: spectra bowstrings
Post by: jeffp51 on December 11, 2015, 10:27:07 am
Jeffrey, are you sure you weighed your strings right? Thats about 10 times what I would expect.
it seemed heavy to me too. I even re-calibrated my grain scale and still got the same weight.  1382gn for a 12 or 14 strand B-50  flemish-twist string with about 7 inches of serving and a paper nock point. Am I just a really bad string maker?
Title: Re: spectra bowstrings
Post by: JoJoDapyro on December 11, 2015, 10:28:07 am
Jeffrey, are you sure you weighed your strings right? Thats about 10 times what I would expect.
Are you looking for grams Badger? It would be an 89 gram string.
Title: Re: spectra bowstrings
Post by: jeffp51 on December 11, 2015, 10:31:24 am
Wait, no--on second thought--I am probably just getting old and my eyes are giving out.  There is a little, tiny decimal point there-so Badger, you are right.  the string is exactly 10 times lighter at 138.2 grains.  I don't know if I feel better now or worse :-[
Title: Re: spectra bowstrings
Post by: JoJoDapyro on December 11, 2015, 10:33:15 am
Wait, no--on second thought--I am probably just getting old and my eyes are giving out.  There is a little, tiny decimal point there-so Badger, you are right.  the string is exactly 10 times lighter at 138.2 grains.  I don't know if I feel better now or worse :-[
Stupid decimals!  >:D
Title: Re: spectra bowstrings
Post by: lebhuntfish on December 11, 2015, 10:46:55 am
Jeff, I've made several strings out of the power pro 50 and 65 lb test line. 8 to 10 strands is enough for just about any bow I've ever made it for. I tend to use 12 strands which is normally over kill but I like the size after I pad the loops with b50. I've done a double serving using the spectra as the first layer then my normal serving as the top layer. I've had trouble with that, serving it by hand. But with a serving tool it comes out nicely. My new favorite serving material is halo serving. With that all I need to do is a single layer and I'm good, as long as I make at least a 12 strand string. It's a bit thicker and it says it's specifically designed for finger shooters. But you will want to have a serving tool for sure.

The string I made for my Fury trade bow was made with power pro. And it's on every bow I shoot. It's about 9 to 12 dollars for 350 yards, easy obtainable and if I need some I can just run to town and pick something up. I'm going to give monofilament fishing line a go for a serving to. I see clay hays do it in one of his YouTube videos.

Patrick
Title: Re: spectra bowstrings
Post by: lebhuntfish on December 11, 2015, 10:53:57 am
Bee's wax is the secret.

+1, that's the only way! Store bought string wax dosent work, trust me!
Patrick
Title: Re: spectra bowstrings
Post by: Badger on December 11, 2015, 12:15:46 pm
  I like the look of linen strings and the no stretch qualities they have. I use 4 strands of d97 and 6 strands of linen in my personnal strings now. It gives me a decent diameter and a good safety factor.
Title: Re: spectra bowstrings
Post by: PatM on December 11, 2015, 12:51:51 pm
I honestly prefer the fishing line over proper bowstring. It's designed to be more abrasion resistant and has a harder finish already on it.
Title: Re: spectra bowstrings
Post by: loon on December 18, 2015, 05:27:31 pm
Is there braided spectra or similar cord suitable for bowstrings? Seems like dyneema and spectra are polyethylene but dacron is polyester.

It would be much easier to just tie a knot in the end using relatively thick braided knot than to make a flemish twist or endless loop string. I got a nice looking pvc bow from Tommy Hard which came with such a string (dacron), with knots on the ends.