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Main Boards => The Bowyer's Bench => Topic started by: John Malone on April 11, 2018, 10:37:50 PM

Title: Is this grain ok?
Post by: John Malone on April 11, 2018, 10:37:50 PM
Guys this is the straightest hickory grain I could find. I made a 58 pound un backed board bow with grain that wasn't straight and it still shoots fine. This is hickory backing on a maple bow. Every thing seemed fine, at about 20 inches 45 pounds I heard a crack. Found a  lil bump not even a splinter on the very edge. I rounded the corners a good 1/4 inch before i satrted tillering. , I sanded it down thought about it and kept going. No more problems until 24 inches again 45 pounds and I heard a crack, still just a tiny raised spot you could barely feel with a finger nail exact same spot. Am I stupid and the grain is off?  Or is there something else i should be looking at. Im not haveing very good luck with hickory as a backing.
Also i was advised to make it 1/16 i forgot and its 1/8 thick.
(https://i.imgur.com/8Xl2ivVl.jpg)
(https://i.imgur.com/l9RBWirl.jpg)
Title: Re: Is this grain ok?
Post by: BMorv on April 11, 2018, 11:07:03 PM
The grain looks good to me, but as I'm sure you know you are always taking a chance when you cut your backing from a board as you don't know how it was handled after being cut. 
I don't think it being 1/8" hurt you at all.
Can you feel it more when the bow is stressed more, like when it's braced vs not braced? 
Title: Re: Is this grain ok?
Post by: John Malone on April 11, 2018, 11:22:05 PM
BMorv I know the risk that's what I'm wondering. But no it doesn't feel any different braced or in braced. I'm going with boo from now on screw hickory. Unless I cut the tree myself.
Title: Re: Is this grain ok?
Post by: Bowjunkie on April 12, 2018, 05:46:23 AM
Understand too... what most folks call 'grain' is really just the growth rings. The actual grain runs perpendicular to the growth rings, radiating outwards from the center of the tree. And so... in a quartersawn or riftsawn backing piece, it's possible for the growth rings to run straight down lengthwise, while the actual grain runs out from front to back i.e. out the 'face' of the bow. It would be virtually impossible to see at that point... unless it let go and raised a splinter like yours did  :dunno:

One reason I like to cut my own trees too.
Title: Re: Is this grain ok?
Post by: BMorv on April 12, 2018, 09:50:22 AM
In just about all of my failures the lifted splinter or chryshal gets worst when the bow is bent, so you would be able to feel it raise higher at brace.  How does the maple look at that spot?  What I'm thinking is that if you round the backing edge too much the hickory will be very thin almost not there and subjecting the maple to carry some tension.  I had a core splinter under a very thin edge of bamboo.
I also sand my backing very smooth, like to 600 grit or smoother before  I pull on it.  Not sure if it's necessary but I am sure it doesn't hurt.
 
 
Title: Re: Is this grain ok?
Post by: Wolftrail on April 12, 2018, 12:06:55 PM
"Every thing seemed fine, at about 20 inches 45 pounds I heard a crack."    Yep I know I heard that dreaded tick a few times myself.  And then Bang the limb explodes into 3 pieces.  This is why I back lam/board bows the fabric seems to keep the wood together rather than hitting me.   But I never go through the trouble of backing until the bow is shot in.