Wonder How Long This One Will Last?

[timbuckII]

Here are a couple of pics of the latest try. Straight grain Hickory, 67” KTK, 1 ½” at the widest and ½” at the tips. Slightly rounded belly, 7” handle area, no taper from the fads to the tips. Brace height right at 6".
 My question: If it is going to break when will it? I know there is no standard answer but I had one pop on the tree and another go at full draw right after measuring the weight. I mean do they usually fail early in life or are they subject to go any time.  I have done a few laminated. Longbows and recurves with no problem but these Hickories are a challenge.  

TBKII

I hope I got these sized right

 

 

[John Scifres]

Get the midlimbs working some more.  Looks good.

[Pat B]

Hickory generally will not break unless it has fungi problems. It may bend badly(generally your fault) but I have never had a hickory bow break.   Also, hickory likes a flat belly rather than a rounded or slightly rounded belly. It is relatively weak in compression and having a crowned belly will concentrate the compression stresses down the center of the belly and not along/across the entire belly where it needs to be.

[John Cooper]

I usually at least TRY to keep away from wood bending that close to the fades right off the bat.  It tends to create too much set in the place that magnifies set.  I usually try to sneak up on that bend in the last few inches of tillering.  Now, it doesn't always work out that way!  haha... If you're getting a lot of string follow right now, try looking up "heat treating" or toasting the belly on this site.  It works miracles on white woods and cuts down on what Pat is saying about hickory being relatively weak in compression.

~John

[Jeff Smith]

What does the front profile look like? That will give a clue as to where that bending should start, a picture would help.Hickory loves to be toasted but I do it before it takes set and try not to scrape too much off the belly after toasting  it.hickory is super tuff and will tolerate alot of mistakes and still yield a hunting weight bow.
Jeff

[George Tsoukalas]

I agree with John. Get the mid limbs bending more. If it breaks it will break just past the handle where the bulk of the bending is happening. I'm assuming you did not do any reflexing. It will last as long as it will last and if and when it breaks you can make another one. Jawge

[timbuckII]

Ok, how do I get the mid limbs bending more? I am willing to try.
 Front profile is flat with just the edges taken off.
  I will look up heat treating. Would that be done after getting the mid limbs bending more? I would think so.
 And you right the last one that broke broke just past the fade and the other was at a small worm hole or knot.

 Thanks, TBKII

[John Cooper]

Most of the strain on a bow is right out of the fades.  That's why you make it widest there.  In volume 4 of the Bowyer's Bible, the author tillers it out to full draw with "A healthy 1.5 inches string follow" then he toasts the belly and adds reflex at the same time.  After allowing the wood to regain some moisture after a couple days, he'll do the tillering by taking wood off the sides.  I haven't made a bow using this method, but it seems very logical.

[George Tsoukalas]

I would work with a scraper like tool. Unstring the bow, and take off wood from mid limb on. Count the passes on each limb. String it up, exercise it at short pulls of 10 inches or so. Check tiller. There are buildalongs on my site. Jawge
 http://georgeandjoni.home.comcast.net/~georgeandjoni/

[John Scifres]

Scrape wood off the belly.  Scrape where it doesn't bend enough and leave it a lone where it bends too much.  I use a cabinet scraper but a butcher knife or scissors held at 90 degrees works too.

  Tillering 101

[timbuckII]

Ok I tried heat treating…unfortunately I did not read the directions through to the end, I stopped at if a limb is twisted. Did not read brown is good black is not but I only had one REALLY black spot, I was trying to do two things at once. I worked one limb at a time and moved a couple inches after each heating, I tested the temp at the wood and got about 375, end of heat gun about 2 ½’ away from wood, max temp on the gun  is 1000. First limb went good, took about an hour and 10 to do the first. Worked all the way up until about 3” from the fades, let it cool all the way down and started the other end. That’s where I screwed up about 8” in from the tip I let it get way to hot, I continued on hoping that it would be Ok. I let it sit for a day but as soon as I tried floor tillering, very slight pressure, the burnt spot snapped off.
 The other end, although probably too dark looks, looked, good. I will try it again and pay more attention to what I am doing. I made a cull based on a proven R/D here at the house. All is not lost though, I cut it down at the break on both ends and it will become a kids bow. Six grand kids only one with a bow so it won’t go to waste. I would have taken pics but the camera is AWOL.

 TBKII

[Pat B]

It generally takes more than a day for the wood to rehydrate. It is not just the wood cooling that is important. When you heat treat you drive the moisture out of the wood and it needs time for the wood to rehydrate before stressing it. Depending on the R/H I would give it 54 days to a week or more before stressing.