Tri-Lam belly question

[RomeoWhiskey]

Long time lurker, first time poster.

I have a lot of experience making fiberglass bows but as a result of lurking here and wanting a new challenge I've been toying with all wood ones.  A few failures, but the last couple have turned out pretty well (experimental red oak bamboo backed).

I'm trying a r/d bamboo backed hickory with a purpleheart power strip, hard maple riser and purpleheart.  My question is would purple heart be OK for the belly strips?  I think it should work OK, but given my experience is largely with glass (and you can sandwich just about anything between glass and it will work) thought it might be a good idea to ask first.  Actually let me expand a bit, are there any woods not recommended for the belly in a tri-lam?

Any thoughts would be appreciated.

RW

[okie64]

Purpleheart is one of those woods that likes to fret if used for a belly lam. Ive used it for powerlams and tip overlays and it works great for that and would probably be ok as a core lam also but the times I've used it for the belly it fretted. It just doesnt take compression as a belly lam very good. Lots of different woods can develop frets on the belly if not tillered properly. Osage is the most forgiving and rarely ever develops frets.

[RomeoWhiskey]

Thanks a ton!  You caught me just in time, was heading downstairs to the workshop to finish up the riser fades and slap the belly lams on.

I'm saving my single Osage board for a future backed bow (once I get a few successes under my belt), guess I'll have to stick with hickory.

Thanks again.
RW

[okie64]

Ive used beefwood and ipe also as belly lams with good success. Hickory works good but can take a lot of set if you're not careful. Keep it wide and at a low moisture content and it works fine.

[RomeoWhiskey]

I proceeded with the hickory backing for lack of any other options on hand.  Bow seemed to turn out.  Initial tillering went well, so well in fact I jumped a bit ahead and began some finishing work.  Handle formed, tips on.  I was really happy with it and couldn't wait to shoot it.  I ended up putting a string on 2 inches longer than I usually would for a 64" bow.   Expected no problems given that I had tillered it at greater than brace height and....

 
 
 

Seems to have cracked along a grown ring which ran off at the sight of the crack.  Couple of lessons learned, 1) if the wood isn't perfect trying to keep a 70lb draw was stupid 2) patience patience patience (I keep thinking I've learned that but apparently not) 3) the all wood bow is a tougher nut to crack than I was expecting.

Alas, back to the drawing board...which is all part of the fun.

[RomeoWhiskey]

Just received a bunch of bamboo, so I think I'm going to try a bamboo backed bamboo tri-lam next. I'm going to say that may be idiot proof...although I may be understating my ability to reinvent the idiot.

[Buemaker]

Yak, too bad after all that work, you seem to have had alot of work with that handle section also with inlays and stuff. Even after 25 years of bowmaking I still sometimes break one, I am a bit impatient too. Bue--.

[RomeoWhiskey]

Yes, I had more than a few hours into it.  I can't say I was too heart broken though, I enjoy the process a great deal and the failures are almost as fun as the successes and twice as instructive.