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Main Boards => The Bowyer's Bench => Topic started by: lablover on March 05, 2009, 09:04:00 AM

Title: Bamboo backing question
Post by: lablover on March 05, 2009, 09:04:00 AM
Have been attempting a short bamboo backed bow and keep having problems with the boo spliting length wise. What am I doing wrong?
Title: Re: Bamboo backing question
Post by: Apex Predator on March 05, 2009, 09:19:00 AM
Maybe leaving the edge of the boo too rough?  I try to smooth things out along the edge before exercising the limbs very much, and never had a problem.
Title: Re: Bamboo backing question
Post by: Pat B on March 05, 2009, 09:30:00 AM
Can you post pics?  Is it splitting along the grain? From the nodes or just along the internodes? Where did you get your boo from? was it already a glue-up when you got it?
Title: Re: Bamboo backing question
Post by: bjansen on March 05, 2009, 12:01:00 PM
I just made a bamboo backed bow, finished it and put it in the oven overnight (100-120 degrees) to dry it out prior to finishing, which caused it to split just as you described.  Could your problem be heat/drying related as well.
Title: Re: Bamboo backing question
Post by: No-sage on March 05, 2009, 03:12:00 PM
If your bamboo is not dry when you glue it on your slat, it will tend to crack once it does dry.  Once it's glued in position, it cant move as a whole, so it cracks.

Bamboo is like hickory, in that it sucks up moisture.  It has to be real dry before you use it.  It also changes shape quite a bit when dried.  If you flatten a piece of damp bamboo, once it gets dry enough to use, it won't be flat anymore. It will have cupped towards the back, making the flattened side convex.
Title: Re: Bamboo backing question
Post by: lablover on March 05, 2009, 03:27:00 PM
I dry the bamboo befor glue up and keep in the box untill I glue it up. It normally splits with the grain just into the very surface, it does not render the bow unshootable, just ugly.
Title: Re: Bamboo backing question
Post by: lablover on March 10, 2009, 09:18:00 PM
want to thank everyone for the ideas going to give another try. see how it goes. I'll let you know.