Primitive Archer

Main Discussion Area => HowTo's and Build-a-longs => Topic started by: JackCrafty on January 26, 2008, 02:46:08 pm

Title: Sinew Bowstring Technique
Post by: JackCrafty on January 26, 2008, 02:46:08 pm

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)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020692.jpg)
I try to get the strands as consistent as possible.  This makes it easier to splice in the correct amount.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020693.jpg)
Once I have a good pile, I sit down with my dry sinew and a sharp knife and cutting board.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-17-08/S4020793.jpg)
I trim any bulky ends (of the stands) off with the knife.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-17-08/S4020794.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-17-08/S4020795.jpg)
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.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020698.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020699.jpg)
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).
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020700.jpg)
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 (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)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020701.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020702.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020703.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020708.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020709.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020710.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020712.jpg)
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.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-11-08/S4020713.jpg)
Here is the string laid down next to a completed bow (for size reference).
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020727.jpg)
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.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020726.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020729.jpg)
I roll up the string, dip it briefly in the bowl of water, and then remove the excess water.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020730.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020732.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020734.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020735.jpg)
I place the string inside a towel and apply pressure with my foot
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020736.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020737.jpg)
I then place the loop over something high,
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020738.jpg)
twist the string down the whole length,
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020751.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020747.jpg)
and clamp a weight to the end of the string (about 4lbs in this case).
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020748.jpg)
The string's original length was 58" before the twisting.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020742.jpg)
And about 57" after the twisting and clamping the weight to the bottom.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020754.jpg)
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.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020749.jpg)
The string is a little over 3/16" wide now....
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08/S4020741.jpg)
The string after a couple hours of drying...it's about 1/8" in diameter,
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08-2/S4020770.jpg)
and about 61" long (it stretched about 7%)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-12-08-2/S4020760.jpg)
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
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-17-08/S4020792.jpg)
About 3/16" just below the loop.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-17-08/S4020784.jpg)
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-17-08/S4020789.jpg)
About 1/8" wide.  This will work for bows up to 60# draw weight with no problem.
(http://i246.photobucket.com/albums/gg112/jackcrafty/10-17-08/S4020786.jpg)

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.

Title: Re: Sinew Bowstring Technique
Post by: Justin Snyder on January 26, 2008, 06:59:29 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

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on January 28, 2008, 05:05:37 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.

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on January 28, 2008, 03:26:40 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.

Title: Re: Sinew Bowstring Technique
Post by: nugget on February 02, 2008, 08:52:26 pm

I am not familiar with the reverse twist. I always make flemish strings. What is the reverse twist?
Nugget

Title: Re: Sinew Bowstring Technique
Post by: DanaM on February 02, 2008, 08:54:35 pm

If yer making flemish strings, guess what your reverse twisting 8)

Title: Re: Sinew Bowstring Technique
Post by: nugget on February 02, 2008, 09:02:39 pm

Ok, Then I just twist up two strands of sinew then make a flemish string?

Title: Re: Sinew Bowstring Technique
Post by: 1/2primitive on February 05, 2008, 09:44:25 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

Title: Re: Sinew Bowstring Technique
Post by: PK on February 14, 2008, 02:27:52 pm

 :)

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on October 11, 2008, 10:36:50 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.

Title: Re: Sinew Bowstring Technique
Post by: Bowbound on October 13, 2008, 02:33:15 pm

Thanks for posting. I need to get my hands on some sinew now.

Title: Re: Sinew Bowstring Technique
Post by: orcbow on October 17, 2008, 07:39:59 am

Thanks for the excellent info and advice on making the sinew string!!!

Title: Re: Sinew Bowstring Technique
Post by: swamp monkey on April 07, 2012, 11:09:11 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.

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on April 08, 2012, 02:32:36 pm

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

Title: Re: Sinew Bowstring Technique
Post by: philwalker on September 23, 2013, 08:50:19 am

Know anyone who sells sinew strings? Need 58 to 64 in strings.

Title: Re: Sinew Bowstring Technique
Post by: BowEd on September 23, 2013, 09:22:57 am

Thanks for sharing this jackcrafty.I've done some of this in the past.I'm impressed with yor prep work on your sinew before twisting.Cutting off hard ends and getting consistently thick strands.Amount of water used,and amount of weight used.Someone wanting to sinew a bow would benefit from this too.Makes a big difference on the outcome of the job.

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on September 24, 2013, 08:15:13 am

Phil, there are a few guys out there who make sinew bowstrings for sale.  Be prepared to pay about $1 per inch.

Sometimes there will be an ad in Primitive Archer Magazine for sinew bowstrings and such but I haven't seen one lately.  I can't put direct links to non-advertisers here but I know Colgrovebows might have some.  I don't know any others off hand.

You could try starting a thread in the Trading Post section and trade someone for a bowstring.

I would make one for you but I'm swamped right now.

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on September 24, 2013, 08:18:46 am

Thanks Beadman!  Glad to see that this old thread is still useful.  I've got some youtube vids on this subject too:

http://www.youtube.com/watch?v=PmZibFv1Si8&feature=c4-overview-vl&list=PLCB1D0FA9FE0BFB7D
http://www.youtube.com/watch?v=GfPmv1IuvqA&feature=c4-overview-vl&list=PLCB1D0FA9FE0BFB7D
http://www.youtube.com/watch?v=vtAw1z12dDc&feature=c4-overview-vl&list=PLCB1D0FA9FE0BFB7D
http://www.youtube.com/watch?v=i5dxWVv3Eos&feature=c4-overview-vl&list=PLCB1D0FA9FE0BFB7D
http://www.youtube.com/watch?v=06eaHFQGkiM&feature=c4-overview-vl&list=PLCB1D0FA9FE0BFB7D

Title: Re: Sinew Bowstring Technique
Post by: BowEd on September 24, 2013, 08:45:09 am

jackcrafty.....I too am a bit maticulas about my sinew prep work.Especially for sinewing bows.Makes for a very nice efficient use of the sinew with very little sanding if put on correctly.I personally use fast flight string because I shoot a lot but can appreciate your attention to detail and devotion.People think I like working with sinew and I tolerate it well but what really drives me to use it is the quality of performance and durability it has.To me it's some magical stuff.Thanks for the you tubes they'll be fun to watch and learn from.

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on September 24, 2013, 09:05:50 am

Ed, I use fastflight too (on my hunting bow).  I'm thinking of making a sinew + fastflight string.  Maybe 75% FF and 25% sinew.  The sinew will be just for looks, of course.  I'm thinking it will be durable enough for hunting in bad weather but still look "real".  What do you think?

Title: Re: Sinew Bowstring Technique
Post by: BowEd on September 26, 2013, 05:29:04 am

I've never been a fan of trying to decieve anybody.Kind like trying to hide a lamination of clear FG in a natural materials bow ai'nt it?But do what you want.Your far too dedicated and accomplished of a craftsman to go that route.Guess I'm talking principles here.I can get on a soap box once in a while.Sorry.
There is a gray line though in the rules of judging BOM.Just so the operating parts of the bow are all natural I guess is the bottom line.

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on September 26, 2013, 11:33:41 am

Yeah, it's also like soaking the tip of an antler pressure flaker in super glue, using an acrylic binder for natural pigments, adding a drying agent (japan drier) to boiled linseed oil, flake-over-grind (FOG) arrowheads, and lots of other things.

I have to admit that I've given in to the temptation many times...   >:D


But probably not this time.  Just a thought.  :)

Title: Re: Sinew Bowstring Technique
Post by: BowEd on September 26, 2013, 11:42:24 am

Yes I heard one fella say to me as soon as your drive your truck to the edge of the woods and start your chainsaw up you are not primitive no more......LOL.I don't agree with it that far really though.

Title: Re: Sinew Bowstring Technique
Post by: JackCrafty on September 26, 2013, 11:50:15 am

 ;D