Horn Bow - video Buildalong

[bowstick]

I want to post a video build along... is there a way to embed "you tube" video on this site?   example of the code is:

<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/7v_n9kYRqnc"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/7v_n9kYRqnc" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>


Until i can figure out how to post the video here, I will just link to them.



This first video demonstrates how to decide which way to split the horn, and shows how to split the horn on the bandsaw.
http://youtube.com/watch?v=7v_n9kYRqnc

This video shows the proper way to mix the bowgrip 100
http://www.youtube.com/watch?v=LNWCRU_lQ6c

And this video shows the proper way to mix in the thickening agent:
http://www.youtube.com/watch?v=RISRffxDbjY


In this next video I show how you should prepare the gemsbok limbs before filling it with bowgrip.
http://www.youtube.com/watch?v=B5oEfEtpodw

This link shows the filling process
http://www.youtube.com/watch?v=gksLivGefbA


I will add more to this when the horns come out of the heat box

[aandu]

Great work there mate...! Now I have someone with whom I can clear my doubts...!I want to know the core you are using... I am planning to use bamboo for the core and use horn/sinew for the belly/backing and Mulberry for the risers...

[Marc St Louis]

Not quite a horn bow, Justin. I wonder how an insert of a hardwood like IPE shaped and glued in would work instead of the epoxy

[Justin Snyder]

I think it would definitely meet the PRIMITIVE standard we like to see in bows posted on PA if it had a wood core instead of epoxy.  The way it is, it is questionable for PA.  Justin

[bowstick]

It's still a horn bow.  Just because it didn't take a year to make, or wasn't made from steamed and flattened horn, sinew, hide glue and fish glues... doesn't mean its not a horn bow.  Try thinking outside of the box, it's refreshing.  I'm coming up with new ideas and techniques.... but hey, thanks for the  support ** sarcasim **

Justin and Mark...  A wood core would be nice, but will not work.  The depth of the horn is approx 1/2 - 3/4"... so add the thickness of the wood, along with the thickness of the horn and the glue line, and you do the math.  The draw weight would be well over 100#.  The epoxy is great because it does not have the same density as a hardwood and will not add a lot of draw weight.  I am aiming for a 55# @ 27" bow, not a 120# war bow.

Also, as for this being "questionable" for PA, I really disagree.  Look around on the site and notice the other bows that have used modern glues to make there bows... Am I using to much glue for you?   

If this post is removed from the website for being questionable... then every other bow on this site that has used smooth on, urac, any other 2 part epoxy, or non primitive material better be taken off too.


Justin

[Justin Snyder]

You are right that all glues are allowed.  I just think there is some difference between an entire core/belly of epoxy which will be doing the compression work, and glue holding two pieces of wood where the wood does the compression work. We do like thinking outside of the box, but we also like to keep it primitive, after all this is "Primitive Archer."  Justin

[bowstick]

Well sir, I am not done with the build along yet... the last layer on the bow will be a thin layer of hickory... which will be doing the compression work.    

But if an american indian had a piece of gemsbok horn and some hide glue, I'm sure he'd do the same thing

[welch2]

American Indian's did and do still make horn bows. But I have never seen an Indian bow with the horn on the back. Then they probably knew that horn is  very strong in compression and should be on the belly.

Ralph

[Jesse]

Maybe none of my business but I think bowstick is right about the glue thing. While less glue may be considered more primitive it is still not primitive. The selfbows on this site are the only bows that are really primitive. Even the guys who chop there trees with stone probably throw it in there car to get it home and dry it with some non primitive method and when its finished it gets a few coats of poly or something. Lets stop splitting hairs. We all have a lot in common on this site.No fiberglass carbon ect. but who uses more glue than the other is not important. Peace.              Nice video bowstick.

[bowstick]

Ralph.... Why "Should"   horn be on the belly... ?? Only because it is good in compression?  So horn should only go on the belly because of its superior compression characteristics?     

What about Horns awesome Tensions properties? Horn on the back makes an excellent bow!  One of the smoothest pulling "Horn" bows you'll ever feel.   

It seems the majoraty of People on this site are very open-minded about new things - as long as they're exactly like the old ones.

Justin

[DanaM]

I looks like this comes down to a difference of opinion (see rule #3) on what is primitive? Don't think you will
agree on anything. Both Justins have good points but each to their own. I don't have a problem with yer post
but then again I don't really care either. You are both talented bowyers but your visions differ.
In the end I guess its up to PA as it is their website and were just their guests so refer to rule #5 "play nice"

Take it or leave it, just my opinion.

[welch2]

Horn SHOULD be on the belly because it is much stronger in compression than tension ,and it is heavy. Here is a quote from a government study
   "The average yield
stress was 14.3 MPa for dorsal wall horn and 10.7 MPa for abaxial wall horn in a three-point
bending test, and 56.0 MPa for bulb horn in a compression test on samples with 100 mm2
surface area and 4 mm height." 

Their data showed a 5 times greater compression than tension strength .So if you make the the same bow ,but put the horn on the belly ,you can use 5 times less horn and get the same draw weight. Making a much lighter bow.
  But if you don't mind the extra weight , and just want to make a bow from horns fast ,go for it .
Here is a link to the report I quoted above.
https://archive.ugent.be/retrieve/2896/FranckEtAl_Biosyst_Eng_R1.pdf

Of the common bow making materials horn is the only one ,that I know of, that is stronger in compression than tension. (5 to 1 )
Wood is stronger in tension and of course sinew has excellent tension characteristics.

Nothing at all wrong with trying new things ,and thinking 'outside of the box '  I'm just suggesting you make a bow just like this one ,but from the other halfs of the horns (you won't have to use as much horn),and strung the other way .Then compare your two bows.

Ralph

[medicinewheel]

hi justin!  -  'outside of the box' is a great place to be, be there with no biased opinion at all and try new things, sure!

...but horn has been used on the belly - NEVER on the back as far as i know - for over 4000 years throughout asia and other parts of the world for exactly the reasons welch anounces here! i don't know any ratio numbers but i bet bamboo beats horn tension-wise by far - and with only a split part of the weight being added to your limbs.
and here comes my point: i personally have a very high neurological sensitivity and i'm therefore in a constant quest for the bow with less handshock  a n d  60 to 70 pounds of drawweight! - i shot 50 arrows out of a well-made hornbow of 100 pounds with no noticable effect on my nervous system at all. i shot ten arrows out of a 50 pounds bamboo-backed longbow with an epoxy-filled (car-filler i recall he used) gemsbockhorn belly a friend of mine had made: beautifull and original bow - traditional enough for my taste - but i suffered from that handshock a long time! plus - due to the heavy limb weight - the bow was not performing very well!

frank

[makete]

I really liked the videos on the build along horn bow. Primitive or not it is way cool.

[PatM]

In one of the early issues of PA there was a letter from a guy showing a Gemsbok horn bow that had the hollow belly side filled with carefully shaped Osage glued in place.
 So it can be done without pulling 120 lbs. The bow described was about 50 as I recall.
 There seems little point in making one of these bows except for the "Fantasy" look.
 There are several examples of solid horn bows, including a few in TBB. Horn will handle tension fine if it is long enough, but then you are no longer taking advantage of its compression qualities. It's a material that needs to be maxed out to make it worthwhile.
 There is a more or less solid horn bow on the Ambush bow contest thread  on the Bowyers Journal site.
  Pat