using single piece wood for cores and many horn pieces for the belly?

[Robert Pougnier]

Hello!

New member to the forum here and avid bowyer. I'm working on a some horn/wood/sinew builds for the first time and have a few questions. I've read through most of the horn bow forum but I hope I'm not repeating old threads. I'm attempting to assemble several bows this fall/winter and hope to have them broke in (or broken) this spring/summer. Since the available material on various methods is still relatively sparse to this day I was hoping to answer some of my questions here. Thank you!

Has anyone experienced with using multiple shorter lengths of horn? I've read that using a butt splice on a non-working portion of the limb is safe. I believe that Jim Hamm suggests using up to 5 shorter pieces on one belly, with one splice around the fades and a second toward the exterior of the limb. Has anyone tried this? I have both long strips and shorter horns that I am planning on experimenting with. I have both american bison and water buffalo horns that are about 16 inches long whole. I haven't processed them yet.

My other question concerns core woods and methods. I have a nicely reflexed elm stave that I am considering using for a single piece core. I have not read anywhere about folks building horn bows with a single piece, though there a many severely reflexed self bows with stiff siyahs. I know that the core is usually built backward of a self bow, so I was curious if anyone has played with this. I've had good success inducing steep and thick curves using steam.

I'll lay out the specs and combinations of core and horn materials methods I plan on using below. If anyone with experience would like to chip in some thoughts, I'd really appreciate it

#1 Ottoman horn bow. 50" ntn, single piece elm core used with the outer growth ring as the back/sinew side. Two long water buffalo horn strips for the belly and WT deer leg sinew for the back (likely 3 or4 layers). Hide and fish glue mix for the bond. I know this is a little bit longer than typical for these but it's my first and I want a bit of room to breathe. I'm shooting for a 65-80# @ 28" draw. I believe it's not really worth making these at a lower draw weight otherwise you underutilize the materials?

#2 Ottoman horn bow. 48" ntn, sugar maple core. Apple or maple siyahs, glued with a v splice. Same horn/sinew combo as above and same glue. Same range of draw specs but built using instructions found in Karpowicz's book for the core joints.

Next I want to play with the shorter horns I got to see if this works:

#3 Korean bow. 48" ntn, apple core with maple siyahs. I plan on trying three 12 inch strips of water buffalo horn. My question here is whether i should use the inside or outside bend for this. Or should I use an inside bend for the handle/fade piece and two outside strips for the mid/outer limb. The siyahs will be six inches, glued with a V splice and side-laminated with horn strips. I also expect to glue 3-4 layers of sinew on the back

#4 Egyptian bow. 50" ntn, sugar maple core made with single piece and outer ring as back/sinew side. four 12 inch strips of american bison horn strips with butt joints at the handle and somewhere mid limb and sinew wrapping at the joints. This one will just have a sharply angled and setback handle and long but fairly even and gently recurve along much of the limbs. I believe this design produces a more even strain along the whole limb and is not built the same as many composites with distinct siyahs.

I do plan on grooving all my mating surfaces and using a fish and hide glue combo for my joints. My understanding is that a mixture of both allows for a longer set time while maintaining good strength and elasticity.

 
Anyways, I know this is a mountain of work, and there are so many variables here. I will try to post pictures of them at various build stages and hope to tease some feedback out of folks! I expect some setbacks and long wait times so please go ahead poke some holes in this as there is plenty of time for me to course correct, and plenty of other projects to build!

Thanks folks!

[sleek]

Well, first off, WELCOME TO THE FORUM! Thank you for joining in I wish I had authoritative knowledge on this subject but your questions are certainly good ones, and joining horn like that is something I have wondered about muself but never asked. Id wager it may work with a sinew wrap at the joints. May try it on a wood laminated bow to avoid loss of time and material on a sinew horn bow.

[Robert Pougnier]

Well thank you!

I am definitely planning to wrap the joints about an inch on each side with sinew/glue.

I might try that, I've never made a wood laminate but the time made up (by not wasting more) and the learning would be well worth it. I wonder if short wood lams would take compression in a similar way to the horn with butt splices? Though maybe I should lap them? Or do you mean trying a laminate with a one piece wood core?

Sorry I lumped a few questions in the same post!

[Robert Pougnier]

update:

I've been spending multiple days cutting, steaming and flattening 4 buffalo horn halves. The outer ones have been doing great, but the inner ones are delaminating some. The curve on the inside is very tight, which is part of the issue. I've made sure not to steam them too long.

I decided to use only the outer halves, which means i now need to process two more horns.

Since I do have some flat strips I bought, I've decided to use these for my first build to eliminate some variables and also to save myself some extra work. I'm doing some final prep on a single piece ash core. I just need to deflex the handle a bit. After recurving it, it's only 45" NTN. I was not counting on that much shortening! It started as a 52" piece before recurving.

I'll be grooving the pieces today and tomorrow, and then sizing them for a couple days before I assemble. I'll post pics before I glue up.

[Bob Barnes]

welcome to the group.  You do have lots of interesting projects planned.  Please post pictures of your progress.   

[superdav95]

Welcome to the dark side of bows!   We don’t get much action over here but when we do it’s on! That’s an ambitious list of bows you got planned.  I can do what I can to answer some of your questions where I dare to.  I’m no expert either but have made some horn bows over the years.  Adam’s book was my main resource actually and made some of my own personal tweeqs along the way.  Here are a few thoughts from your list.  As for a single core wood sections I would say for sure would work but need to make sure you have the thickness needed where you will need it.  Maple is the preferred core wood for many makers.  I know elm has been used also with success.  I’ve not yet tried elm but do not doubt it would work.  Using multiple pieces of horn on the handle areas may be fine but I personally would not do it extended into any portion of bending part of the bow.  If I were to hazard to guess though I would say you may be better to test this multiple piece horn belly on a more conservative build like a Mongolian or relaxed ottoman bow perhaps then on a Korean which are typically very very reflexed and under a lot of strain on belly.  I would stick to one solid piece of horn on each limb on the Korean.  I have experimented with horn spliced bellies with some success and some failures. It’s mixed bag and I still have yet to determine what went wrong for sure.  I use bamboo for my Korean builds.  I carefully choose either matched spacing in nodes for each limb or a single piece and add the handle build up section later on the sinew side.  I’ve done builds with rind side in and rind side out.  On the Korean builds I score only with very fine grooving tool.  They are not matching grooves.  I use only sturgeon bladder glue for this.  Not a mix.  I make this glue from the the inner bladder scrapings of air bladders of the sturgeon.  Croaker bladders also work well too but I have better access to the sturgeon bladders fresh.   The sinew layer I use a mix of home made sinew only glue and sturgeon glue. About 30% mix glue 20% sinew glue to 10%sturgeon glue.  The steam bend of rind side out builds with bamboo are possible but the bending is easier to make with rind side in (belly side).  I am actually testing a couple of these now with rind side out bend limbs to see if any difference in strength or cast.  Grooving is important on bows over 50lbs.  It would be a shame to put all that effort in to only find a lot of time and resources wasted.  Ask me anything you like and if I can answer I will do my best.  Again I’m not expert but have learn a bit over the years of breaking and making which is the best way.  Best of luck on your builds.  Lots of guys here to help.  Adam’s book is where you can get your measurements and details on dimensions.   Persona message me too if you want.  I just posted some update progress pics on my build yesterday so there may be infor over there that may be of some help to ya.  Welcome to the dark side.  lol.