Author Topic: Sinew Bowstring Technique  (Read 28780 times)

0 Members and 1 Guest are viewing this topic.

Offline JackCrafty

  • Global Moderator
  • Member
  • Posts: 5445
  • Sorry Officer, I was just gathering "materials".
Sinew Bowstring Technique
« on: January 26, 2008, 11:56:56 am »
THE FOLLOWING HAS BEEN MODIFIED SINCE THIS WAS FIRST POSTED BACK IN JANUARY.
PICTURES HAVE BEEN ADDED, ETC.

First, I pound and separate the DRY sinew into strands.
It doesn't matter too much if you pull apart the sinew from the middle or the ends, especially if the pieces are on the short side.
The strands are about 1/16 of an inch wide (or less) with no hard spots.  I do not "comb" the sinew.
(This is how much sinew I used for the string...plus a little more: I like to finish off with longer strands)

I try to get the strands as consistent as possible.  This makes it easier to splice in the correct amount.

Once I have a good pile, I sit down with my dry sinew and a sharp knife and cutting board.

I trim any bulky ends (of the stands) off with the knife.


I grab some strands, dip my fingers in the water and moisten them a bit.
I twist the strands HARD and add strands based on experience and the desired strength of the string.
If you do this when the strands are soaking wet, you can't get a good grip and you'll end up with a loose twist and a lumpy string.


The harder the twisting force, the more accurate I can be with the string diameter.
As I'm reverse wrapping the string, I try to remember that at this initial stage, thicker is better.
I've started may times with too narrow a string and had to start over (no fun).

From my experience, I find that a two-ply string is easiest and fastest...although a three-ply looks better.

Here is a video of someone using the same technique that I use for twisting the strands together.
The difference, of course, is that I add splices....and I can't make the string nearly as fast.
(It takes me 1 to 2 hours to make the string, depending on the strength of the string)
http://www.youtube.com/watch?v=9o2qhN1qCdg

As I add strands, I moisten my fingers in the bowl of water and apply water sparingly to the sinew.
(It was drizzly and humid today.....so I didn't need to dip my fingers in the water)







The loop is the most difficult part of the string.
Here I've added quite a few splices to maintain the thickness of the string at the base of the loop.
Sometimes I cut away strands so that this area isn't so thick, but it's easier to just add lots of splices and then taper the thickness down slowly.

Here is the string laid down next to a completed bow (for size reference).

I tie off the end with an overhand knot and admire my new "shaggy" bowstring...
I DO NOT TRIM OFF THE LOOSE ENDS AT THIS POINT.


I roll up the string, dip it briefly in the bowl of water, and then remove the excess water.




I place the string inside a towel and apply pressure with my foot


I then place the loop over something high,

twist the string down the whole length,


and clamp a weight to the end of the string (about 4lbs in this case).

The string's original length was 58" before the twisting.

And about 57" after the twisting and clamping the weight to the bottom.

I then pull the loose ends of the strands away from the string so that it will dry faster.
I DO NOT TRIM THE LOOSE ENDS AT THIS POINT.
If the loose ends are trimmed off, the string might unravel as it stretches and dries.

The string is a little over 3/16" wide now....

The string after a couple hours of drying...it's about 1/8" in diameter,

and about 61" long (it stretched about 7%)

Once dry (overnight), I take down the string and clip off the loose ends with fingernail clippers.
Some of the strands may be stuck to the string: so I just rub the string until they pop up.
I use a lighter or candle to CAREFULLY burn off any remaining "hair" (Note: I don't burn off the "hairs" anymore).
Here's the completed string. ;D

About 3/16" just below the loop.


About 1/8" wide.  This will work for bows up to 60# draw weight with no problem.


That's it.  Now I test it.  I recommend shooting a new string on a sunny day (for starters) and at half draw.  After a few shots, I gradually increase the draw until I've reached full draw and shot the bow about 50 times.  This process is what I call "stressing" the string.  After the string has been stressed, moisture will not affect it so much and shooting on humid days is not a problem.  However, if you accidentally get water on the string, unstring the bow immediately and LET IT DRY COMPLETELY before shooting again.

The string can be oiled (to make it softer) or it can dipped in hide glue (to make it stiffer) but I don't recommend either of these things.  You could probably add a coat of beeswax to the string, but I'm not sure that this will make it waterproof....and it will certainly add weight to the string.  I've never used beeswax or any other coating on my strings.

Sinew strings wear out more quickly that any other artificial strings I've used (nylon, Dacron, polyester) but there is a special feel in these strings.  They are easier to grip with your fingers, they become soft in the area where you nock the arrow, and they are very light in weight.
« Last Edit: October 18, 2008, 01:15:46 pm by jackcrafty »
Any critter tastes good with enough butter on it. :::.

Patrick Blank
Midland, Texas
JackCrafty (youtube)

Where's the Rock?  Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How Do I Cook It?  Light Colors:  200  for 24hrs, 400  for 4hrs, Cool for 12hrs.

Offline Justin Snyder

  • Administrator
  • Member
  • Posts: 13794
Re: Sinew Bowstring Technique
« Reply #1 on: January 26, 2008, 04:10:17 pm »
Thanks for sharing... Sure could use some pictures along with this.
I have never heard of anyone that doesn't soak the sinew before they wrap. I can see that it may be easier to work with, but I wonder how it might effect the strength of the string.  Justin
Everything happens for a reason, sometimes the reason is you made a bad decision.


SW Utah

Offline JackCrafty

  • Global Moderator
  • Member
  • Posts: 5445
  • Sorry Officer, I was just gathering "materials".
Re: Sinew Bowstring Technique
« Reply #2 on: January 28, 2008, 02:16:25 am »
Justin,

I've never had a string break on a bow, although I have broken a string or two during the drying under tension process because I added too much weight.  And yeah, I've got to post some pictures...and maybe make a video.

I've tried soaking the sinew but I ended up with a very irregular string each time.
« Last Edit: October 15, 2008, 02:31:54 pm by jackcrafty »
Any critter tastes good with enough butter on it. :::.

Patrick Blank
Midland, Texas
JackCrafty (youtube)

Where's the Rock?  Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How Do I Cook It?  Light Colors:  200  for 24hrs, 400  for 4hrs, Cool for 12hrs.

Offline JackCrafty

  • Global Moderator
  • Member
  • Posts: 5445
  • Sorry Officer, I was just gathering "materials".
Re: Sinew Bowstring Technique
« Reply #3 on: January 28, 2008, 12:37:28 pm »
I'm adding an addendum to this post because I left out a few quirky things about sinew strings:

-They stretch.  Sinew string works fine on short bows, but long sinew strings amplify the drawbacks of a flexible string.

-They expand and contract with changes in humidity.

-They are food for various critters.

-They look funny.  They are off-white in color...and they look like clothesline from far away.

-They also get "shaggy" with constant use.  If you're a neat freak, stay away from sinew.
« Last Edit: October 15, 2008, 02:40:12 pm by jackcrafty »
Any critter tastes good with enough butter on it. :::.

Patrick Blank
Midland, Texas
JackCrafty (youtube)

Where's the Rock?  Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How Do I Cook It?  Light Colors:  200  for 24hrs, 400  for 4hrs, Cool for 12hrs.

Offline nugget

  • Member
  • Posts: 1995
  • I see, I hunt, I shoot, I eat
Re: Sinew Bowstring Technique
« Reply #4 on: February 02, 2008, 06:03:14 pm »
I am not familiar with the reverse twist. I always make flemish strings. What is the reverse twist?
Nugget
Life is not a journey to the grave with the intentions of arriving safely in a pretty and well preserved body. But rather to slide in sideways, thoroughly used up, totally worn out and loudly proclaiming....WOW WHAT A RIDE!!

Offline DanaM

  • Member
  • Posts: 9211
Re: Sinew Bowstring Technique
« Reply #5 on: February 02, 2008, 06:05:23 pm »
If yer making flemish strings, guess what your reverse twisting 8)
"Prosperity is a way of living and thinking, and not just money or things. Poverty is a way of living and thinking, and not just a lack of money or things."

Manistique, MI

Offline nugget

  • Member
  • Posts: 1995
  • I see, I hunt, I shoot, I eat
Re: Sinew Bowstring Technique
« Reply #6 on: February 02, 2008, 06:13:27 pm »
Ok, Then I just twist up two strands of sinew then make a flemish string?
Life is not a journey to the grave with the intentions of arriving safely in a pretty and well preserved body. But rather to slide in sideways, thoroughly used up, totally worn out and loudly proclaiming....WOW WHAT A RIDE!!

Offline 1/2primitive

  • Member
  • Posts: 1026
  • Bible believing Christian
Re: Sinew Bowstring Technique
« Reply #7 on: February 05, 2008, 06:55:13 pm »
Nugget, nope, the sinew isn't long enough. (Unless you have elephant sinew.  :))
Just keep twisting in the way that you twist the loop. It takes a while.
   Sean
Dallas/Fort Worth Tx.

PK

  • Guest
Re: Sinew Bowstring Technique
« Reply #8 on: February 14, 2008, 11:38:40 am »
 :)

Offline JackCrafty

  • Global Moderator
  • Member
  • Posts: 5445
  • Sorry Officer, I was just gathering "materials".
Re: Sinew Bowstring Technique
« Reply #9 on: October 11, 2008, 07:47:38 pm »
I modified the first entry and posted some pics that I took while working on a bowstring for my "Sinew Backed Double Curve Bow" thread.  I'll post more pics as the string progresses.  I ran out of daylight....so I'll try and finish the string tomorrow.
Any critter tastes good with enough butter on it. :::.

Patrick Blank
Midland, Texas
JackCrafty (youtube)

Where's the Rock?  Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How Do I Cook It?  Light Colors:  200  for 24hrs, 400  for 4hrs, Cool for 12hrs.

Bowbound

  • Guest
Re: Sinew Bowstring Technique
« Reply #10 on: October 13, 2008, 11:44:03 am »
Thanks for posting. I need to get my hands on some sinew now.

orcbow

  • Guest
Re: Sinew Bowstring Technique
« Reply #11 on: October 17, 2008, 04:50:47 am »
Thanks for the excellent info and advice on making the sinew string!!!

Offline swamp monkey

  • Member
  • Posts: 784
Re: Sinew Bowstring Technique
« Reply #12 on: April 07, 2012, 08:19:59 pm »
I used this how-to in order to make my first sinew bow string.  I then was able to make another in short order.  Both are functional.  I was elated. I love finding this kind of quality help and instruction on this web site.  It keeps me coming back. 

heartfelt thanks.

Offline JackCrafty

  • Global Moderator
  • Member
  • Posts: 5445
  • Sorry Officer, I was just gathering "materials".
Re: Sinew Bowstring Technique
« Reply #13 on: April 08, 2012, 11:43:24 am »
Thank you for kind words, m'friend.  Glad to see this thread is still alive.  It took me a while but I also have a youtube video series on this topic.  The video explains the process of the actual "twisting" better.  (shameless plug...heheh).

Again, thank you.  made my day.   ;D
Any critter tastes good with enough butter on it. :::.

Patrick Blank
Midland, Texas
JackCrafty (youtube)

Where's the Rock?  Public Waterways, Road Cuts, Landscape Supply, Knap-Ins.
How Do I Cook It?  Light Colors:  200  for 24hrs, 400  for 4hrs, Cool for 12hrs.

Offline philwalker

  • Member
  • Posts: 5
Re: Sinew Bowstring Technique
« Reply #14 on: September 23, 2013, 06:01:07 am »
Know anyone who sells sinew strings? Need 58 to 64 in strings.