Compression cracks

[PEARL DRUMS]

Can compression cracks be fixed with wrapped sinew and glue? Are there any other ways to fix them short of a belly lam?

[4est trekker]

Replacing or removing the damaged wood from service is really the only way (i.e. partial or belly lam, Torges patch, plug, etc.) Everything else is just a cosmetic disguise for an eventual failure.  Sinew functions in tension, not compression, and wrapping it doesn't address the problem.  I just posted a fix on the Trade Bow thread, but the chrysal was very small and isolated.  The technique I posted is most helpful when dealing with suspect pin knots or small compression fractures (which in this case was caused by suspect/damaged wood.)  PatB has properly suggested the use of belly lams on here before to correct chrysaling and has posted a bend through the handle osage recurve that was successful.  I think Bona (bglass) recently posted a successful one as well, although she did so to increase the draw weight.

Regards

[PEARL DRUMS]

This was my first Argentine Osage experience. I would rather not blame it on the wood, but I have to. The bow was built on the same recipe I always use with American. It was 80% tillered and looking very good when I seen the cracks. very disheartening to say the least. I took two 8 hour days tillering this bow like a baby......The wood had alot of swirls in the grain and I brought that to my suppliers attention right away. He said he would send out a new piece if this one broke. Thats the good news.

[John Scifres]

You can also reduce draw weight and/or draw length and salvage a shooter.  If there was a defect in the belly, it can be removed and patched with a compression similar wood.  If the design wasn't appropriate for the wood, you have to redesign.

[PEARL DRUMS]

I have a bunch of thin American laying around, I may try that . The bow is 66" long, 1 1/4 wide tapering to 1/2" tips half way up with a very thin hickory back, maybe .100" thick, heavily trapped even. I still can belive the belly crushed like it did.

[Pat B]

The repair that 4est mentioned I made was to add Argentine osage belly lams to the belly of an American osage bow. I was very pleased with the results. I think I'd try the American osage belly lam on the Argentine osage bow.  
  I just ground down the belly below the frets and glued the belly lams on in reflex and when the Urac cured I retillered the bow. It went from 45#@26" to 56#@26" when completed(60" static recurve, bend through the handle). I got the belly lams from David Knight. They were scraps he had that happened to be tapered from about 1/8" to 0" in about 20".
  I'll have this bow at the TN Classic next weekend if you want to see it and/or shoot it. It is now my primary bow.

[Steve Kendrot]

I too have a couple bows that have developed frets in the final stages of tillering. I've wondered if anyone has tried to glue layers of Osage shavings (kinda like layering sinew) on the belly to build it back up without having to flatten the whole limb and glue a lam along it's length.

[Pat B]

Wood shavings are all grain violations. Not strong enough for anything other than kindling.
  If you have a belt sander it will only take you 10 minutes or so to flatten the belly.

[PEARL DRUMS]

What about cutting the area out and gluing a new "square" in its place? I was advised to try that out.

[Pat B]

That takes pretty precise cutting and fitting I think. I've never done that.

[Walt Francis]

I have used Torges method a few times with good results on BBO's.  I have sent you a link to his method.

[Stiks-n-Strings]

I just patched a bow with a Torges patch and it worked great.

 I had talked to Pat and was considering a belly lam but took out the first patch and tried it again and got it right the second time.

[Stiks-n-Strings]

I just patched a bow with a Torges patch and it worked great.

 I had talked to Pat and was considering a belly lam but took out the first patch and tried it again and got it right the second time.

[PEARL DRUMS]

I assume the the Torges patch should be done now before I dink around with the tiller anymore?

[Stiks-n-Strings]

Yeah Pearl. I had to do mine after I had the bow tillered and it took a little set in that area. I drew it on the tillering tree and did not like the way the first one looked so I ground it out and repatched. I'm pretty sure the set happened at that point but it ain't real bad. Turned out to be a fine shooter. If I getg a chance I'll post some pics.

 Stiks

[PEARL DRUMS]

I would love to see pics. I checked out Deans tutorial that Walt sent me, he ticks me off. Every video or article I read he makes this stuff look so dam easy! Maybe I could send it to him for repair? The man is good at what he does for certain. The weather is miserable today...............again. So I may just head to the shop and see what happens.

[PEARL DRUMS]

Well I ground the bad spot out and replaced it with 1/4 sawn osage. The fitting took be a good hour, but it fit perfect. I used URAC to hold it down and no clamps per Deans instruction. It looks good, now we shall see if it works! The bow is basically tillered and done, may need a slight tweak after the plug drys. I will keep you posted on my progress.

[SEMO_HUNTER]

How bout some pics? I'm not sure I've ever seen what your referring to? I'd like to see what you all call compression cracks because I have seen some tiny little cracks in my finished products before, but you can only see them when you hit the wood with some kind of stain. Otherwise they are invisible.

[PEARL DRUMS]

Those are from compression Chris, thats what I tried fixing. They will generally worsen over time and more will show up, at least in my experinece. I puled the bow this morning to 25#'s and the hickory back blew. On to another!

[Stump73]

You might think this is a stupid question, But what does a compression crack or fracture look like? Any pics?  Thanks Mike