Primitive Archer

Main Discussion Area => Bows => Topic started by: kevinsmith5 on March 29, 2013, 01:54:26 pm

Title: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: kevinsmith5 on March 29, 2013, 01:54:26 pm
How does that proposed combo sound? A 1/8" hickory back, 3/32" Jatoba, 3/8" ipe, shooting for 1 1/8" wide and 76" ntn with a bendy handle. I have all those woods on hand but could swap the Jatoba for maple or another wood if I make a run to the hardwood lot.
Title: Re: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: kevinsmith5 on March 30, 2013, 10:16:41 am
I guess no one has any views yay or nay?
Title: Re: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: paulsemp on March 30, 2013, 10:43:16 am
hickory backed jatoba make a nice bow. never did a tri lam with ipe.
Title: Re: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: AH on March 31, 2013, 10:58:05 pm
yup it will most likely make a good bow. Lots of laminate war bows are hickory back, _____ core, Ipe belly. I think the Jatoba will be a good choice for core, As it makes a pretty good belly wood too, in my experience. :)
Title: Re: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: Joec123able on March 31, 2013, 11:42:14 pm
Ipe is amazingly strong in compression and hickory is amazingly strong under tension alot of people use that combination an I'm sure Jatoba will work fine for a core
Title: Re: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: cdpbrewer on April 12, 2013, 08:03:02 am
This post is probably too late...  If not, use maple for a core instead of jatoba.   Maple is less dense than jatoba (0.56 vs. 0.77 average s.g.) so the bow will be a bit faster.  An added factor is the core of a trilam isn't stressed as much as the back and belly so the core doesn't need to be of high strength wood.  Save the jatoba for the belly of your next trilam.  Maple is less expensive also.   
Title: Re: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: kevinsmith5 on April 12, 2013, 06:08:12 pm
Would soft maple work? (I've got that in spades)
Title: Re: Tri-lam ELB combo-hickory, Jatoba, ipe?
Post by: cdpbrewer on April 12, 2013, 07:51:48 pm
Kevin,  I've only used hard maple (aka sugar maple).  You might try cutting off a thin piece of the soft maple you have and bend testing it.  Keep in mind it's for a mid lam tho'.   

FWIW, here's an thread that has a post or two on soft maple:  http://www.primitivearcher.com/smf/index.php/topic,4945.msg68190.html#msg68190   

And another thread where someone says soft maple is not good:  http://www.primitivearcher.com/smf/index.php/topic,2294.15.html

Neither thread addresses using soft maple as a mid lam but both cast aspersions on silver maple.   

Strength properties of various maples are on page 5-5 of the Forest Products Lab "Wood Handbook" at http://www.fpl.fs.fed.us/documnts/fplgtr/fpl_gtr190.pdf

c.d.