Horse Bow

[RomeoWhiskey]

I have a serious desire to build a horse bow.  Unfortunately, can't find much data to direct me.  There are a few builds and a smattering of info here and there but nothing detailed enough to really guide the process...so I'm winging it or at least rule of thumbing it with some images as my only real guide.

My plan is to go with a 52 inch with 4 inch siyahs.  The bow (as planned) will be a trilam with bamboo backing (1/8 inch thick), ipe core (1/8 inch parallel) and bamboo belly (1/8 inch thick).  I'm planning on making the siyahs out of ash and have them at 60 degrees. The shape will be something like this:

  http://www.kestrelarchery.com/images/ufhb.JPG  

The riser will be something like this:

  http://www.kestrelarchery.com/images/ufhb_03.JPG

I'm targeting a 50lb draw at 28", but wouldn't mind if it falls short of that.  I'm toying with the idea of a black glass belly instead of bamboo to simulate horn and I'm toying with the idea of using fiberglass cloth to back it instead of bamboo.  Basically, I want something that works and something that gives me a point to build from.

Any suggestions on how to better approach this?   Anyone have any history making this type of bow?  I'll do a build along if there's enough interest.  The ol' horsebow doesn't get much love around these parts.

RW

 No pics over 640 pixels

[Pat B]

Look for Adam Karpowicz's book "OTTOMAN TURKISH BOWS manufacture and design". It has everything you need to know for these composit bows.

[Jaikarr]

I own a Horse bow and would love to see a build along of so I can get an idea of how it was made.

[KellyG]

You can get gemsbok horn off the auctions sites. That is the only place I have seen it. There are builds on here using them.

[SEMO_HUNTER]

FWIW~

The only advice I could offer on this subject is about the IPE, it's not at all forgiving of a single mistake. I found this out the hard way along with many others. Your tiller has to be perfect or it will make toast out of your bamboo backing. I'd just suggest that you use a different wood than IPE for your first horse bow build, then work your way up to the IPE when you get your process refined.

[RomeoWhiskey]

Semo - thanks for the advice, in my excitement of the new project I did ignore it    as Ipe was what I have on hand, but it's definitely noted.

As indicated, I get a project idea in my head and can do nothing else until I work it through so...

I decided for my first horsebow to go with Ipe and a fiberglass cloth backing.  I figure it will give me the best chance of success of of the blocks, allow me to begin to develop a process for making a more traditional version.

I started by ripping 2 1/16 Ipe strips.  I don't want a very heavy draw, and I have a sneaking suspicion this might end up drawing more than I think it will anyway.  I left the strips parallel in the hopes that it will give me a bit of room to tiller and because I really have no idea where I'm really wanting this thing to bend at.  I'm going for a 52 inch bow plus 5 inch siyahs.

The first real challenge was developing a shape for the bow.  I had a general idea what I wanted as depicted above, but I took some time and drew it out to scale.  I was particularly concerned about the riser shape. To make a pattern for that I laid out the ipe strips on my form like so.

 

I secured everything, then traced the shape at the riser area onto a piece of pine.  Once I shaped that up and got a nice fit, I traced the form onto a block of ash and cut it out and sanded it down.

 

 

After getting a nice snug fit.  Moved to glue up.  This will actually be a two step process.  The first was the wood-wood glue-up.  I used TBIII (again because it's what I had on hand this evening).  I wrapped it in shrink wrap, then rubber bands, then put it in the form and added some C-clamps to the riser area to ensure good connections in that area

 

 

And that's it for tonight.  I plan to let it be for 24 hours then I'll take everything off, clean it up and go to glue-up step two which will be backing it with fiberglass cloth using bowgrip.  Tomorrow evening I'm going to work on the siyahs.

RW

[RECURVE319]

The last time I spoke to Adam he was using hophornbeam as a core. I had the pleasure of shooting a few of his bows, real screamers. Great to see a build along.


Rick.

[KellyG]

Will tbIII dry if wrapped like that?

[Pat B]

The moisture from TB glue has to go somewhere!Encapsulating your glue up like that is trapping the moisture in the wood.

[RomeoWhiskey]

True. I worried about that initially when I started with all wood bows and definitely find it's still wet around the edges when I unwrap.  However, I figured that in a tight joint like those between laminations of a bow no air's getting in there anyway.  The bows do holds the form and if I leave it alone for an additional few hours seems to do OK.  Let me caveat that I'm by no means an expert here but based on my limited experience with the 5 or so bows (hickory and bamboo backed) I've done with TBIII in the last 3 months I've not had any problems with delamination which is equal to my success rate with the 5 or so I've done with Urac.  I guess so far I've gone with TBIII when I'm experimenting (which given my novice status is pretty much all the time) and Urac when I think I have a keeper.

I had not considered the trapping the moisture in the wood though.  Wouldn't the nature of the joint sort of force that anyway?  I mean if you watch glue dry (boring as it may be) the exposed area outside the joint dries first theoretically creating a moisture barrier which would force the moisture into the wood anyway...right? At least that's how I've rationalized it thus far).  How relevant do you think this level of absorption would be to the wood's properties given a kiln dried wood  and the amount of H20 in 6 oz of TBIII?

Yet another factor to consider which is exactly why I posted this. Thanks for the tip.

[Cuban Missile]

I'm finishing up a horse bow right now.  So far yours is looking pretty good.  I wouldn't worry about the water.  People wrap their bows in plastic wrap all the time and that holds water as well.

On a different note since its all wood pay attention to the set that you get in this bow because you might wan't to add a little more reflex on the next one, and take care how you laminate the siyahs on.  You don't want those pulling off.  I shudder every time i think of that happening.

[RomeoWhiskey]

Re: reflex, seemed like plenty last night but looking at those picks it may be lacking.  Was too chicken to go with a full "C-curl".  Maybe next time.

I'm planning on epoxying them and wrapping them with artificial sinew and then epoxying the wrap.

I've got the same reaction when I think of those things popping off.  I imagine them popping off simultaneously and becoming a very fast moving nun-chuck.  Not a pleasant though.  One could
definitely put the proverbial eye out with that one.

Post some pics of your bow if you have a chance.  Would love to see some other examples.

RW

[RomeoWhiskey]

Here are the siyahs.  5 Inches with groove one inch from the tip.  3/4 of an inch wide.  The main piece is just shy of 1/2 inches and I'm going to glue a piece behind it for added strength.  

 

I'm going to epoxy them on, wrap them with artificial sinew then super glue the sinew.  They'll also need some additional shaping to guide the string, but they'll need to be attached before that's possible.

Here's the bow after I unwrapped it and cleaned it up a bit.

 

 

It's definitely going to need a backing and as per the plan I'm using fiberglass cloth/tape (whatever you'd call it).

 

I've used this on a hickory board bow it and worked nicely.  Came out clear, just a little textured.

More to come.

RW

[RomeoWhiskey]

I think it was Forest Gump who said "Stupid is as stupid does" in this case stupid is the guy who places a TBIII bonded bow into bow oven to cure the epoxy on the fiberglass.... Brilliant!

When you're stupid, pains the only way you learn I guess.  Will clean this all up and start the glue-up over.  Think I'll be using smooth on this go round.  Probably get a better result anyway.

RW

[SEMO_HUNTER]

I'm not afraid to waste a little Urac on any project even if I think it's got a high chance of failure because there's always that chance that it won't fail. Urac is the best for all wood projects hands down, it's never failed me.

[RomeoWhiskey]

I do need to keep some in stock, it's the lack of a local supplier that makes me treat it like gold.

[Bowtech94]

have you finished this bow yet? I have a strong desire to build one like this also.