@#$^& tillering problem...please help!!!

[Springbuck]

There is a lot of good advice and a lot of "well meant" advice on this post.  Let me help you sort it out.

  1.  Ipe is awesome bow wood and if you can get some (which shouldn't be too hard) it is a heck of a wood to back with bamboo.  I would use ipe like crazy if it didn't irritate my nose and lungs so badly.  It's cheap, hard, elastic, strong and can look good.

  2. No shame in hickory board bows (that's a self bow, BTW, but some split stave purists won't let you think so).  Hickory will tolerate almost anything you can throw at it, design-wise.

  3. Wherever you live, there has got to be some wood available, if you WANT to make sapling bows.  Elm grows all over, and there are a dozen dozen small shrubby trees suitable for sapling bows.

  4. Hickory holds world records, when backed with bamboo, but there are caveats. Where I live, in the dry desert, guys like Dan Perry have set lots, if not most, of the distance records in the class with bamboo backed hickory or hick-backed hickory.  Boards are fine, too, BUT, if you live where humidity is higher, you MUST take precautions.  Perry reflex the bow; this makes it seem more stressed up, when actually it is LESS stressed.  Choose your boards carefully.  Get solid, heavy hickory, preferably a tightbark specie such as pignut or shagbark. TRAP THE BACKING as well as thinning it.  HEAT TREAT the belly, too, early on, maybe even before you glue up.  Keep it indoors in the AC while tillering. Think ahead.

  5. Many of the things suggested here couldn't logically have happened.  That is a FRET, a MAJOR compression fracture.  If the boo "overpowered" the hickory in general, you would have lots of frets of whatever size and lots of set.  That is not set, that is a crushed spot in the limb.  There has to be a better explanation.  Either you didn't see the hinge, you have an abrupt transition, the wod is way too wet, or there was a weak spot in the wood, or an overly strong spot in the bamboo (I dunno what that means, but it is a logical possibility).

  6. Reading up on the TBB's and other books never hurts.

[otis.drum]

canshooter,
did you reduce the notches in the bamboo? i can't see clearly in the photo but it looks like it occured just near one of the notches. the notches are often stronger and put more pressure on the belly wood. likewise the boo on one side of the notch is usually slightly thicker than the other.

a side-on photo would be handy.