Primitive Archer
Main Discussion Area => Bows => Topic started by: sleek on April 24, 2018, 06:29:00 pm
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I wonder to the compressive strength of hair if bound in a hide glue. Perhaps a good soak, tightly bound and vaccume bagged.
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is human hair strong in compression?
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i mean ive heard that hair is stronger then steel in tensile strength but idk how true that is
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The museum in natural history in London has this to say.
Hair is strong. A single strand could hold 100g (3oz) in weight: the combined hair of a whole head could support 12 tonnes, or the weight of two elephants. Weight for weight, it is not as strong as steel: more like aluminium, or reinforced glass fibres or Kevlar, which is used to make bulletproof vests.
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damn that is impressive but isnt that tensile strength?? or m i missing something
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sleek:
Cool idea and worth testing. Most new ideas don't work, but so what. When used as a bow string it has a lot of stretch, so might have high hysteresis. Easy enough to find out. Horse tail might be the easiest, being so coarse. Hide glue might not like sticking to it. Maybe test that separately. When ready for the belly test maybe glue up thin bundles, as if preparing sinew for backing, letting each fully dry before setting in place and pouring glue on. This will way speed belly drying time, and reduce shrinkage,
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https://www.google.com/amp/s/www.researchgate.net/publication/280610881_Evaluation_of_mechanical_properties_of_human_hair_bombyx_mori_silk_fiber_reinforced_epoxy_based_biocomposite/amp
This is fascinating. Not as much info as I am searching for, but still makes me think hair can work in a bow, but more likely as a back than a belly.
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Hmm... So hair is made of keratin right, and so are finger nails and rhino horn, those last 2 are definitely a good deal strong and flexible. I also looked it up and hair wont melt, it just softens then burns. Maybe you could make a test piece of hair in a glue matrix and test it out first. (-P
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Hmm... So hair is made of keratin right, and so are finger nails and rhino horn, those last 2 are definitely a good deal strong and flexible. I also looked it up and hair wont melt, it just softens then burns. Maybe you could make a test piece of hair in a glue matrix and test it out first. (-P
too bad it wont melt, then i could melt it into a mass.
Of course, different hair colours will have different strengths. Mines brown. Diet may matter as well.
Im gonna go to the barber for a trim, see what can be done as a test. I need to figure out the test parameters. How well it holds together in a glue matrix, resistibe forces etc...
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SMH
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SMH
Lol what? SMH? Shaking My Head or Shaving My Head?
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I presented my horsetail horn hypothesis on here years ago. The problem with hair is finding glue that sticks to it as well as the natural binders of keratin in horn..
It's easy enough to experiment with modern glues but that kind of defeats the purpose.
One of the things often overlooked when gluing natural fibers is that they tend to have surfaces as slick as the rind of bamboo. So you may think you are gluing them up well but on the inside the glue is not actually sticking to the fiber at all.
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SMH
Lol what? SMH? Shaking My Head or Shaving My Head?
Lol shake*
Hair.... well it’s kinda like baleen. And baleen makes a great backing material. Hair I think will be difficult to apply compared to baleen.
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I presented my horsetail horn hypothesis on here years ago. The problem with hair is finding glue that sticks to it as well as the natural binders of keratin in horn..
It's easy enough to experiment with modern glues but that kind of defeats the purpose.
One of the things often overlooked when gluing natural fibers is that they tend to have surfaces as slick as the rind of bamboo. So you may think you are gluing them up well but on the inside the glue is not actually sticking to the fiber at all.
Perhaps using a chemical agent that will etch the surface of the hair to allow better bonding? Vinegar? Diesel? Maybe boil it in a soap water to remove oils?
As a last resort, grind it to a pwder and use it as an additive to the glue to make a thick paste to the point its almost not even sticky anymore. Then it will be more hair than glue, hopefully giving best results.
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I presented my horsetail horn hypothesis on here years ago. The problem with hair is finding glue that sticks to it as well as the natural binders of keratin in horn..
It's easy enough to experiment with modern glues but that kind of defeats the purpose.
One of the things often overlooked when gluing natural fibers is that they tend to have surfaces as slick as the rind of bamboo. So you may think you are gluing them up well but on the inside the glue is not actually sticking to the fiber at all.
Perhaps using a chemical agent that will etch the surface of the hair to allow better bonding? Vinegar? Diesel? Maybe boil it in a soap water to remove oils?
As a last resort, grind it to a pwder and use it as an additive to the glue to make a thick paste to the point its almost not even sticky anymore. Then it will be more hair than glue, hopefully giving best results.
Yes, for advanced natural composites which are becoming more popular these days tackling the bonding problem is usually done with Sodium Hydroxide or similar and silane treatments etc.
A lot of research goes into this.
You can get some pretty advancedFflax and Hemp fabrics these days that are used in demanding aplications where glass or carbon would typically be used.
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The problem with hair isn’t really the oils fromwhat I look up, it’s the outer layer that gives it it’s strength. This outer layer is made up of a bunch of twisted bundles. That’s what is making it so slick. I wonder if using pine pitch instead of hide glue would work ???
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where would you get it?
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I bet it will glue. Bubblegum don’t have a lick of problem sticking and staying stuck
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Gees, What have you guys been smoking?
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I'm with Morgan, my sister and my two daughters had long hair, glue it with whatever is in bubble gum.
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I bet it will glue. Bubblegum don’t have a lick of problem sticking and staying stuck
What is the binding agent? Xanthym gum? Its a natural glue. Mix that binder with a drying agent, and call it a day
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When used as a bow string it has a lot of stretch,
but in the the paper you posted it seemed a lot better in compression than tension. although it was in a matrix so you would have to factor that In
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Ok, gum is natural rubber fron tree sap. I dont think that can be hardened.
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I meant if bubblegum sticks and stay stuck, surely a glue will as well? Maybe not, but if it’s something you want to try, it’s be worth putting a dob of whatever glue on a board and sticking some hair in it and see if you can pull it out once cured.
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I just remembered a milk based glue called casein. I recall it gets really hard. Im gonna buy some horse hair for experiment. Seems to me, being hair is a protein, a protein based glue like casein would bind it.
Im thinking to soak the hair for a period of time, then put the strands in a welded metal box, then compress it with a hydraulic press until dry. I want to match as close as i can the density of horn. Then use the density ratio of hair to horn, and build a bow with that percentage in mind, like say its 75% of horn density, i would build the bow 25% larger than a horn bow of equal weight.
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Surely it should be used in tension on the back?
Medieval siege engines used sinew for the ropes twisted up in torsion, but in emergencies (if your town was besieged) human hair was used (according to Ralph Payne Galwey's book The crossbow )
Del
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Well del, I read its very stretchy. It will go to 1.5 times its length without breaking. That would be like putting rubberbands on the back, without the spring back, because it has a point of no return where it wont spring back. I think a back is supposed to resist tension, not go willingly.
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Well del, I read its very stretchy. It will go to 1.5 times its length without breaking. That would be like putting rubberbands on the back, without the spring back, because it has a point of no return where it wont spring back. I think a back is supposed to resist tension, not go willingly.
But isn't sinew similarly stretchy? ...
Quote from the Wiki page on siege engines:-
... The skein that comprised the spring, on the other hand, has been cited specifically as made of both animal sinew and hair, either women’s and horse.[40] Heron and Vegetius consider sinew to be better, but Vitruvius cites women’s hair as preferable.[41] The preferred type of sinews came from the feet of deer (assumedly achilles tendons because they were longest) and the necks of oxen (strong from constant yoking).[42] How it was made into a rope is not known...
Del
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Without any experiance, i can say for certain. Its strong for certain. I dont know how stretchy is too stretchy though.
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So, i wonder, who here has experience with casein glue aka milk glue?
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Unlike hide glue casein glue is fairly waterproof, and will adhere to somewhat oily surfaces. Strength tests I've done show it to be about half as strong as hide glue, which is strong enough for most purposes. Never done decent elasticity tests. The strongest casein glue I've made used washed and strained low-fat cottage cheese and 5% lime. Mix well, let set for an hour then use. Low pressure clamping if at all.
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Some hide glue info:
The higher the gram strength of hide glue the quicker it gels, often too quickly. One solution is to keep the work, sinew and air at high temperature. Another is to dilute the glue.
Hide glue you make yourself, from sinew scraps or hide scrapings will typically yield about 180 gram strength glue, gels slower for longer working time, and is stronger than needed for about any imaginable need.
Gelatin glue is about 350 gram strength.
How to mix it:
http://www.frets.com/FretsPages/Luthier/TipsTricks/KitchenGlue/kitchenglue.html
Three times water weight to dry glue weight is difficult to mix. Six times is easier.
The lower the water content the quicker a sinewed back or such will dry.
Dry hide glue is about 1.3 specific gravity, twice as heavy as many bow woods.
Tensile strength up to 10,000-plus per square inch.
The lower the moisture content the higher the tensile strength, and vice versa
Can be stretched 5% to 10% of length.
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Now I wonder about using a hybrid of casein and hife glue with blood mixed in for good neasure?