Author Topic: Help with warbow lamination thickness  (Read 3120 times)

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cool_98_555

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Help with warbow lamination thickness
« on: November 09, 2013, 02:24:36 pm »
Hello everyone,

I am making a trilam warbow and I will be aiming for 120-125# at 32".  The osage I have is only 5/8" thick.  The hickory I have is 1" thick.  The bamboo backing strip is 1/8" thick.  I would like to start out with 1.25" thick at the handle and .75" thick at the tips so I have some extra thickness to work with.  I am planning on starting with 1 3/8" wide at the handle.  My question is regarding the thickness of the laminations.  If I put osage on the belly of the bow and I put hickory in the core, then to get 1.25" of thickness I would have 5/8" of osage on the belly and 1/2" of hickory in the core.  This is the option I would prefer, but I am not sure if 1/2" is too thick for a core wood.  Does it matter how thick the core wood is, or does it just serve as a spacer between the back and belly?  My 2nd option is to put hickory on the belly, and in this situation I would have 1" thick hickory on the belly and 1/8" thick osage as the core wood.  I am planning on rounding the belly, and I do realize that osage is far better in compression than hickory, so these are considerations as well.

Any insight on this would be greatly appreciated.  Thank you!
« Last Edit: November 09, 2013, 02:30:20 pm by cool_98_555 »

Offline adb

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Re: Help with warbow lamination thickness
« Reply #1 on: November 09, 2013, 08:13:08 pm »
First off... hickory sucks as belly wood, especially for a heavy draw weight bow.

IMHO ditch the bamboo, as well. Just my opinion. I don't like bamboo. Use hickory on the back, and osage on the belly. Do you have access to anything else as a core wood? Like purpleheart, or greenheart? Ipe?

If you want 120-130#, you'd need about 1.25-1.5" wide at the grip and at least 1.25" thick.

I think a 1/2" lam would not be ideal, especially as the core. I use 1/4" or less, for back and core, regardless of weight.
« Last Edit: November 09, 2013, 08:41:18 pm by adb »

cool_98_555

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Re: Help with warbow lamination thickness
« Reply #2 on: November 09, 2013, 08:24:17 pm »
I can buy purpleheart, greenheart, or ipe, but it would cost me more.  I would prefer to use what I have.  Why is it ideal to have 1/4" or less as a core instead of 1/2"?  Is there a particular reason or is that personal preference?  I could use 2 of the 1/4" hickory laminations instead of a 1/2" lam, if that would work.  That would be a quad-lam though.

Thank you for your response!
« Last Edit: November 09, 2013, 08:27:46 pm by cool_98_555 »

Offline adb

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Re: Help with warbow lamination thickness
« Reply #3 on: November 09, 2013, 08:34:11 pm »
With a 1/2" hickory core, you'll end up with less ideal belly wood. You'll make a better bow with a more dimensionally appropriate core thickness. So, if you use a 1/2" thick hickory core, you can't remove any of it while tillering. You'll end up removing more of your compression strong osage, and will likely end up with none at the tips.

More osage than hickory on the belly would be my first choice. But, it's your choice and your bow.  ;) I've never understood why bow makers are hesitant about spending another $10 - $20 on another piece of wood, for a bow that will likely last a lifetime.

Offline adb

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Re: Help with warbow lamination thickness
« Reply #4 on: November 09, 2013, 08:40:43 pm »
OK... I admit it. For no other reason...  I want the bows I make to look pleasing to the eye. IMHO, how a finished bow looks is important to me. If the laminations are proportionate, I like how it looks... balanced and pleasing.

Offline toomanyknots

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Re: Help with warbow lamination thickness
« Reply #5 on: November 09, 2013, 08:51:36 pm »
First off... hickory sucks as belly wood, especially for a heavy draw weight bow.


I happen to have the exact opposite opinion on hickory anymore. I absolutely love hickory as a belly wood. Although I do agree with you it is not the best choice for 130 + bows, I've done it. I would make it longer than ipe or osage to take the compression better, but I have had great success using hickory as a belly wood, and I think most of the stuff people say about it taking excess set it not true. It definitely ain't true for me. If I glue in 2" reflex, I will be left with close to 1" reflex. If I glue in 1" reflex, I will typically be left with a straight stave. It definitely has the potential to be faster than ipe and osage as well due to it's lighter mass. I just finished a boo/maple/hickory bow, 75# @ 32", with about 2" glued in reflex, it held about 1" of it, that is just after being unstrung after being shot. And it is very fast and smooth, really light in the hand compared to ipe or osage bows. I really like this combo. I have stated countless times on here, I just don't understand hickories bad rap. If I was getting set and chrysals, etc, than it would make sense to me. And I definitely don't heat treat.
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline adb

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Re: Help with warbow lamination thickness
« Reply #6 on: November 09, 2013, 09:12:41 pm »
Not me. I've had horrible 'success' with hickory on the belly of anything, except maybe flatbows. It's just so much better on the back... so that's where I leave it.

cool_98_555

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Re: Help with warbow lamination thickness
« Reply #7 on: November 09, 2013, 09:16:24 pm »
First off, thanks guys for your replies.  I love this forum.  Whenever I can't find the answers elsewhere I ask on here and I always get educated responses from experienced bowyers, so thank you. 

I completely understand that osage is the preferred wood to use on the belly.  I had thought about the problem with the thickness at the tips if I use that route (osage as the belly wood and hickory as the core wood), and that the osage would be almost down to nothing at the tips.  Then I thought, "what if I use hickory on the belly?  I have a full 1" thick of that, and with osage in the core as 1/4" I could get 1 3/8" thick at the handle....but I know that hickory is notorious for being superior in tension.....not compression."  If I used osage on the belly and only used 1/4" of hickory in the core, my thickness in the handle would only be 1", and that's not enough thickness for 120-130#.

The strange thing with all of this is that I had just made a bamboo-backed hickory that is 66" and 82# at 32".  I was surprised that it didn't take too much set, even when drawing to 32" on a 66" bow!  Originally I had it at 72" and even then it had less than  .5" of set, but I piked it so I could reduce the mass and raise the draw weight a little at 32".  I say you learn from your mistakes, and I experiment and try something different with every bow I make...not because I set that as a goal, but because I just naturally do it.

I also love to make my bows so that they have an aesthetically beautiful appeal.  In my opinion a bow is a "great bow" if it meets 3 requirements:  Good performance (minimal set, arrow flight, penetration, durability, etc...), beauty (in my opinion), and meeting the specific draw weight and draw length goal that I set before even working on the bow.   ;D