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Trilam Warbow Hickory/Greenheart/Hickory 125-130lbs@32"

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AndiE:
Hi

The Greenheart that Fairbow is selling is Ipe. So the warbow is Hickory/Ipe/Hickory.

Greetings
Andi

mikekeswick:
Toomanyknots - i'm happy to tell anyone all I know about making elb's.  ;) after all it won't take too long.....
Gluelines in themselves add no real stiffness. The glueline is very thin and although most glues are stiff when dry they are forming a tiny percentage of the total thickness therefore have a tiny affect on the stiffness. If I understood what Prairiebowyer said then 3 x 1/8th thick lams aren't very stiff by themselves when un-glued yet they become a lot stiffer when glued together...well of course they do they are now 3 times thicker! That's not the gluelines it's the huge change in thickness.
Regarding reducing limb mass because of adding gluelines - most glues are pretty darn dense so adding more glue will actually raise the physical weight.
I personally don't use heavy dense woods for cores unless somebody specifically wants a certain combination. My favourite core wood is maple due to it's medium density and fantastic gluing properties and it's diffuse porous.
I have found that just shy of 1/4 hickory backing works best will dense tropicals like ipe. This is after making a few hundered of them with every thickness of backing tried...but i'm still not 100% sure why.
The core in a hornbow isn't really to lower limb weight but to work as a) A form to glue the horn to b) give the limbs the correct shape as it's stiffer than horn or sinew c) allow the shaping of the kasans/tips etc. Maple is the best wood for hornbow cores as well!
The one way of making gluelines 'work' is the principle of perry reflexing. I'm still experimenting with gluing up 2 lams at a time and adding reflex with each glue-up...but it's a bit of a pain. End-grain cores are another avenue with potential but i'll leave that upto you to figure out.  ;)

adb:
Making tri-lam ELBs (my speciality) allows me to make more bows with less wood. The glue lines do not add stiffness per say. Remember, wood which is twice as wide is twice as strong, but wood which is twice as thick is eight times as strong.

The glue I use (TB3) happens at the molecular level. A good glue line shouldn't be a line at all... it should just look like the wood is touching each other. Good glue lines are all about proper wood surface prep, and consistent clamping pressure.
 
Gluing multiple layers mostly allows me to optimize the wood combinations and thicknesses. Plus, it provides the bonus of looking nice using wood colors with contrast. What mikekeswick has said above is very correct. Maple is excellent bow wood... one of my favourites. I do tend to use belly type compressive woods for my cores, but I have also used tension strong woods like bamboo as well.

There is also some physics going on at glue lines, which I don't fully understand.  Right at the glue line itself is a neutral plane, where there is neither tension nor compression forces. If you have a tri-lam, there are two neutral planes, and I'm not sure if this is better than one with a backed bow. Something to research, I suppose. I have spoken with and spent time with some very knowledgeable bowyers like Pip Bickerstaffe in the UK, and there must be something to his willingness to make nothing but multiple layered ELBs, otherwise he wouldn't bother with the extra work.

toomanyknots:
Thank you Mike and Abd for the thorough replies, I appreciate it,  ;D.

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