Author Topic: Human hair as horn substitute  (Read 3882 times)

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Offline sleek

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Re: Human hair as horn substitute
« Reply #15 on: August 22, 2021, 04:22:19 pm »
Yo sleek…2 ?s

1.  You know how to post photos on here to bring us along gor the ride, right?!
2.  Is your screen name derived from a particular boat produced in the mid to late 90s?

I think Sleek was produced in the mid 90s... '

Sleek~ missed you at MoJam bud!

I missed MOJAM entirely! Nope, I'm a product of 1983 :)
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline simson

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Re: Human hair as horn substitute
« Reply #16 on: August 23, 2021, 06:04:23 am »
Years ago I did experiments with horse hair as backing. Imbedded in hide glue, epoxi and some other I don't remember. Alternative as a cable backing. All failed terrible. The elastic modulus is too high (stretches too much). No remarkable strengthening, but a lot of additional mass.
IMO human hair has at least the elastic modulus of horse hair.
Well I understand, you want to use it as a facing not as backing.

Good luck!
Simon
Bavaria, Germany

Offline sleek

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Re: Human hair as horn substitute
« Reply #17 on: August 23, 2021, 03:08:02 pm »
The idea is not original to me. Years ago someone mentioned it and I thought I'd give it a try. Last night I took the hair out of the vacuum bag. This morning it's a little harder and stiff. It's starting to curl a little. I didn't make it compact enough, I can see daylight through it. I'm thinking about heating it up and bonding it to a stick of osage. I'd do a bend test before and after to get better data.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline Fox

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Re: Human hair as horn substitute
« Reply #18 on: August 23, 2021, 10:34:30 pm »
  (-P
Why must we make simple things so complicated?

Offline Gimlis Ghost

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Re: Human hair as horn substitute
« Reply #19 on: August 23, 2021, 10:50:10 pm »
Hide glue will favorably bind the hair fibers, due to the porosity of human hair.

I hope so, if not, I'll use sulfuric acid to etch the hair for better binding.

Be careful in treating hair with acid. The WW2 Japanese used a high explosive made from leather scraps mixed with human hair and dissolved by an acid. As this explosive aged it became highly unstable.

Offline Deerhunter21

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Re: Human hair as horn substitute
« Reply #20 on: August 23, 2021, 11:22:20 pm »
Hide glue will favorably bind the hair fibers, due to the porosity of human hair.

I hope so, if not, I'll use sulfuric acid to etch the hair for better binding.

Be careful in treating hair with acid. The WW2 Japanese used a high explosive made from leather scraps mixed with human hair and dissolved by an acid. As this explosive aged it became highly unstable.

do you have any specific citations??? I definitely... dont want... uhhhh.... to make an explosive for fun....  >:D >:D >:D JK, but it honestly sounds interesting!  (lol)
Life before death. Strength before weakness. Journey before destination.

Offline Gimlis Ghost

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Re: Human hair as horn substitute
« Reply #21 on: August 24, 2021, 01:26:39 am »

do you have any specific citations??? I definitely... dont want... uhhhh.... to make an explosive for fun....  >:D >:D >:D JK, but it honestly sounds interesting!  (lol)

Its a derivative of Picric Acid.
Used by many nations through WW1 but mainly replaced before WW2 due to instability. The Japanese developed a method of getting around instability issues and made the substance more powerful at the same time.
Plenty of information on the various forms and uses.

Offline Pappy

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Re: Human hair as horn substitute
« Reply #22 on: August 24, 2021, 02:30:07 am »
Yall are going to have the AFT and homeland security on us if you keep it up.  ;) :) :) :) :) Look forward to seeing how this turns out Sleek. :)
 Pappy
Clarksville,Tennessee
TwinOaks Bowhunters
Life is Good

Offline sleek

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Re: Human hair as horn substitute
« Reply #23 on: August 24, 2021, 03:56:08 am »
Ok, I just measured the thickness of the dried up hair strip. It's 1.64 to 1.45mm thick along its 7 inch length and 1 inch width. It shrunk some and became unstable, making waves along its length, like a ribbon that was laid down but not straightened taught. It certainly has an amount of stiffness too it, standing out like a diving board when held between two fingers. I've bent it around Ina compete U shape with no complaint from it, or any set, with it springing immediately back to flat like a spring when released. So far, on that front, so good. Also I pulled and pushed together a section and half an inch long with a decent amount of effort with no give. However.....

I did a little tugging on some of the individual strands and a few of them, without enough force to break the strands, come out of their glue matrix like a straw out of its paper wrapper. Others are so tangled in there they break without disbanding from the glue. I'm hoping the ones that came loose just didn't have a large enough surface area bonding them. Tomorrow I will cut a strip of osage to bond another sample of hair to in order to get any concrete numbers of increased compression abilities.
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Offline sleek

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Re: Human hair as horn substitute
« Reply #24 on: August 24, 2021, 01:56:53 pm »
I decided to see how it would break today and bent it to a crease. the tension side held, but the belly side broke from the glue and buckled. I would rather have had it snap or tear on the back. Maybe a better method of glue or a better glue is needed. I'm going to find a way to acid etch the hair and try again.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

bownarra

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Re: Human hair as horn substitute
« Reply #25 on: August 24, 2021, 02:26:57 pm »
It's the dried glue that is giving the strip its stiffness.
That is one of the reasons collagen glue is better than using modern epoxy to bond the horn to the belly of a hornbow. Its stiffness when dry is inbetween the wood core and the horn. The wood being the stiffest and gives the bow its shape. The old way of making mismatched grooves on the wood and horn to deliberately not mate up. These 'teeth' in to each surface are filled with glue. The dried glue then give a more subtle transistion to the horn/wood joint. The glue 'strips' acting like epoxy in a modern composite.
Glass strips are made by mildly pretensioning the raw glass then 'glued-up'. The ends are clamped and the clamps spread apart slightly. I've done this when making uni-directional carbon lams for my modern bows (spits). In any uni-directional composite you want the fibers parallel or else you have dead weight and overstrained areas.

Offline sleek

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Re: Human hair as horn substitute
« Reply #26 on: August 24, 2021, 02:41:23 pm »
It's the dried glue that is giving the strip its stiffness.
That is one of the reasons collagen glue is better than using modern epoxy to bond the horn to the belly of a hornbow. Its stiffness when dry is inbetween the wood core and the horn. The wood being the stiffest and gives the bow its shape. The old way of making mismatched grooves on the wood and horn to deliberately not mate up. These 'teeth' in to each surface are filled with glue. The dried glue then give a more subtle transistion to the horn/wood joint. The glue 'strips' acting like epoxy in a modern composite.
Glass strips are made by mildly pretensioning the raw glass then 'glued-up'. The ends are clamped and the clamps spread apart slightly. I've done this when making uni-directional carbon lams for my modern bows (spits). In any uni-directional composite you want the fibers parallel or else you have dead weight and overstrained areas.

So, would you say the glue is doing fine with the hair based on what I've said so far? Realistically I'm playing with far tighter bends on this hair sample than any bow will experience, but also with far less compression than the belly will experience as well. Not certain if the hair will hold inside the glue matrix under pressure.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline ssrhythm

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Re: Human hair as horn substitute
« Reply #27 on: August 28, 2021, 10:56:50 am »
Yo sleek…2 ?s

1.  You know how to post photos on here to bring us along gor the ride, right?!
2.  Is your screen name derived from a particular boat produced in the mid to late 90s?

I think Sleek was produced in the mid 90s... '

Sleek~ missed you at MoJam bud!

I missed MOJAM entirely! Nope, I'm a product of 1983 :)

The Sleek Bob and I are referring to was a whitewater kayak produced in the mid 90s that was no less than revolutionary…so that adds to the awesomeness of your internet screen name even if ya didn’t know it.  It was the “Mullet” of kayaks, as it was all business up front and all party in the back.  It had a high volume creeker front with a concave stern that could be sliced into current to “stern squirt” (stand the boat up straight up and down with the bow to the sky).  Folks went from just running class V creeks to playing their way down them, and that Transition seemed to happen overnight once that boat hit the market.  It may still be the coolest boat Eve produced, and it doesn’t get the credit it deserves rom a history-of-whitewater perspective, as it fundamentally transformed “hair boating” (at least in the southeast US.)  My best friend still paddles one and is always looking for the impossible garage find. 

Anyhoo…thought I’d shine some light on mine and Bob’s nebulous exchange.