Author Topic: Faint crack on belly fix?  (Read 7628 times)

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Offline petew

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Faint crack on belly fix?
« on: March 17, 2012, 10:45:44 pm »
I have an Osage longbow that has developed a faint crack just at the fade on the belly side of the the lower Limb. It runs  across the limb. This bow had develops string follow and I heated it and put some reflex back in, and re tillered it.  To late now, but I should have left it alone.
 What kind of repair is a good bet to stop this from a total failure, if possible?
 I was considering super glue, then scraping some thickness in front of the cracked area to let more limb bend here, and re tillering the limbs?
 It shoots quite nice, but left alone it can only get worse.
 Would adding sinew to the back over the handle and fade work if this is filled with super glue and scraped to sound wood?
 Pete
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Offline Gordon

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Re: Faint crack on belly fix?
« Reply #1 on: March 17, 2012, 10:54:57 pm »
That is a compression fracture - the limb is experiencing too much stress at that point. It's hard to say how best to fix it without seeing it. Pictures of the bow at rest, brace and partial draw would be helpful.
Gordon

Offline osage outlaw

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Re: Faint crack on belly fix?
« Reply #2 on: March 17, 2012, 11:06:26 pm »
Did the crack develop when you heated the reflex in, or was it there already?  Like Gordon said, pictures would help.
I started out with nothin' and I still got most of it left

Offline vinemaplebows

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Re: Faint crack on belly fix?
« Reply #3 on: March 17, 2012, 11:38:37 pm »
Need pics as Gordon said.
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Offline MWirwicki

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Re: Faint crack on belly fix?
« Reply #4 on: March 18, 2012, 12:28:28 am »
If you developed the crack after heat treating, you may be able to salvage it.  I just did it, myself.  Just this week, I made a little bow and I had undulation dips in each limb at near mid-limb.  They were sister billet splices.  It followed the string about an inch when it was done, but appeared to hinge at the dips.  Again, appeared to, just may have been the dips.  Nevertheless, I heated the dip areas and thought maybe I could bend them backwards a bit.  Like you, I cracked the belly side.  Pushed them a bit too far, I guess.  Anyways in each case, I left the limb on the form, keeping the crack open and put CA gel glue in the cracks.  Since the cracks were on the compression side, I thought it would work. 

It worked.  The cracks sealed up and the bow now has about an inch of reflex.  It also gained about 3 pounds in draw weight.  I shot several arrows through it and is holding up well.  I'd show the rest of the bow, but I just dipped it in my finish an hour ago and I'm certain it is still tacky.  The entire bow has trouble spots that I fixed.  It was one of those pieces that I wasn't gonna let beat me.
« Last Edit: March 18, 2012, 12:33:06 am by MWirwicki »
Matt Wirwicki
Owosso, MI

Offline petew

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Re: Faint crack on belly fix?
« Reply #5 on: March 18, 2012, 02:59:12 pm »
The crack appeared after I fixed the bow. :-[  and shot it again. I will try to get  good photos today.It would seem logical that if I scrape down till the crack is gone, and seal the area for safety and luck with super glue, I should be able to feather the limb out to bend more in mid limb and remove some stress that must be concentrated where the crack is I could possibly salvage the bow at a lower draw weight..
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Offline Pat B

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Re: Faint crack on belly fix?
« Reply #6 on: March 18, 2012, 03:30:26 pm »
Pete, if the crack is actually a fret it is the weak part of the limb and is working more than the surrounding areas. By removing the fret you have weakened that area even more.  There are remedies! Removing a chunk of wood from that area and replacing it with another piece of the same wood then reshaping it to the original thickness will allow you to begin tillering again. You could build up the area with rawhide or sinew that would reenforce the area and continue tillering.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline George Tsoukalas

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Re: Faint crack on belly fix?
« Reply #7 on: March 18, 2012, 05:01:39 pm »
You could retiller that limb leaving that area alone. It is bending to much there so retillering will make the rest of the limb do its work. You'll have to readjust the other limb too. You cut that area out and put in some compensating wood in that area. I've had a little success gluing on a piece of rawhide on the belly over the area and extending a little past. Jawge
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Offline petew

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Re: Faint crack on belly fix?
« Reply #8 on: March 19, 2012, 06:35:02 am »
Well a crack, or Fret, in this case, can only grow if it is left alone.
With steel, which I am more used to working with any cracks are removed before repairs are done so it would seem like the best choice here too, so the next step will be to remove the damaged area carefully and glue in a patch. {I can see me getting in over my head again.}
 I have lots of scrap Osage from the bandsaw , so material is not an issue. I assume that I will feather it in on both ends, overlaping the sides. It should go easy. Any sugestions on a glue type to use on the patch.?

Pete
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Offline George Tsoukalas

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Re: Faint crack on belly fix?
« Reply #9 on: March 19, 2012, 11:27:51 am »
If left unfixed the stave will fold up on you like closing a book. That's a tricky fix, Pete.  I've never  tried that one fix. That is not a little fret. That's a big one. You may find it going deeper than you think. I would still retiller that limb and the other or what you are adding for wood may also fret. Remember frets don't appear for no reason. The cause is the wood bending too much in that area. Jawge
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Offline petew

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Re: Faint crack on belly fix?
« Reply #10 on: March 20, 2012, 03:33:42 am »
I still have not got a photo posted, however the photo above is much worse than my fret.Much worse. You have to look hard to see mine and have good light.
 Anyway I made up a patch tonight. It is the band saw trim from when I cut out the bow, and it is from the exact  area, where the problem is. Lucky I keep scraps.
 I will do a flat removal on the limb from the fret area extending about 4" toward the tip, and finishing in the fade with a radiused fit into the fade. The patch is prepared and feathered to nothing at each end.
 I need a precise fit or it will look like a patch, and I have lots of time on my hands. The patch is 1/8" thick so it should add enough material to remove the  hinge that caused the trouble..For glue I need to visit a local bowyer and beg a spoonfull of his glue.
 Sounds simple, but in reality it will be faster to make another bow. I just happen to like this one.
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