Author Topic: Almost done, then pop, creak, crack...  (Read 2991 times)

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Offline txdm

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Almost done, then pop, creak, crack...
« on: April 23, 2017, 06:34:10 pm »
Here's my latest Hickory board bow. It's been my best effort yet up to this point, except a crack is developing.

62"x1.75" wide, 4" handle, 1" fades

Braced:


45# at 26" draw:


The crack in lower fade (bow is at brace in the pics):




Some details:
  • Before I ever cut out the profile of the handle, I heated the roughed stave in a long box with a small space heater/blower. The source of the incoming heat from the little blower was the middle where the handle would be. It pulled a full oz of water off before tillering.
  • There was some really stubborn twist to this board that I corrected with dry heat, though not on the lower limb that is cracked...but, the angle of pull did change some since I re-corrected it a few times as I tillered.
  • It started as a 'tick' while doing some early shooting at low draw (always wearing googles and a Tilley hat), and the tick became a 'creak' once it was back on the tillering board, and that made me stop to take a close look.
  • The handle was still rough, because I like to do it very last.

So, can I save this? I was thinking of bracing it at full draw and forcing TBIII into the crack.

If not, do you think my drying was too aggressive, or was it the twist, or just bad luck with the wood?

Thanks for reading.

Offline PatM

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Re: Almost done, then pop, creak, crack...
« Reply #1 on: April 23, 2017, 07:10:50 pm »
It's mainly because of abrupt stress risers being initiated with your profile shaping. Things need to flow and your working limb needs to be moved out of the fades farther.

Offline DC

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Re: Almost done, then pop, creak, crack...
« Reply #2 on: April 23, 2017, 07:20:24 pm »
Like Pat says. Look where I put the red lines and that whole area should look like it was carved from one piece. You should glue on the handle piece before you cut the handle shape and it should be the full width of the stave.

Offline txdm

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Re: Almost done, then pop, creak, crack...
« Reply #3 on: April 23, 2017, 08:18:11 pm »
Got it, thanks guys. I can do this on the next one.  Now that it's getting close to summer I wont need to futz with drying it so much, too.
« Last Edit: April 23, 2017, 08:25:21 pm by txdm »

Offline bubby

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Re: Almost done, then pop, creak, crack...
« Reply #4 on: April 23, 2017, 09:00:24 pm »
One thing you always need to do before you bend your bow is round all the edges, atleast the radius of a pea, those square corners are where it will lift a splinter
failure is an option, everyone fails, it's how you handle it that matters.
The few the proud the 27🏹

Offline Del the cat

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Re: Almost done, then pop, creak, crack...
« Reply #5 on: April 24, 2017, 02:12:05 am »
You gotta feel a bow, stroke it, you want it smooth and curvy, use your fingers as well as your eyes.
And no need to cut the grip out so narrow until it's near completion, it give you room to line up the grip to the bow limbs which can help with alignment issues.
Certainlt worth trying to save.
Get some low viscosity superglue into the crack with it braced, the ntake the string off. maybe back it with canvas etc or bind it with linen thread at that point... and get the out 1/2 of each limb moving more.
Even if you don't save it, you will learn a lot
Del
Health warning, these posts may contain traces of nut.

Offline Stick Bender

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Re: Almost done, then pop, creak, crack...
« Reply #6 on: April 24, 2017, 05:10:07 am »
Sense its a board bow you could probably remove the handle with heat & exstend it out with recut fades hickory is strong wood maybe worth a shot !
If you fear failure you will never Try !

Offline FilipT

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Re: Almost done, then pop, creak, crack...
« Reply #7 on: April 24, 2017, 06:32:44 am »
Like others said, its simply because your fades are actually flexing (very little but still important). Fades should be part of handle or better said, a gradual transition from handle to limb.

I know this is more difficult than having self bow and carving everything from one piece of wood, but you must do some equivalent of self bow handle, so  a gradual transition. To illustrate what I am talking about see this picture:

Bad example:
(note: laminated bow pictured but its still relevant)


Good example:

Offline Knoll

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Re: Almost done, then pop, creak, crack...
« Reply #8 on: April 24, 2017, 08:07:51 am »
Perfect illustration, Stalker.
... alone in distant woods or fields, in unpretending sproutlands or pastures tracked by rabbits, even in a bleak and, to most, cheerless day .... .  I suppose that this value, in my case, is equivalent to what others get by churchgoing & prayer.  Hank Thoreau, 1857

Offline Marc St Louis

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Re: Almost done, then pop, creak, crack...
« Reply #9 on: April 24, 2017, 08:15:56 am »
The left limb is not working past mid-limb and the right limb could work a bit more as well.  That may have contributed to the crack.

Use crazy glue while the crack is open, it will flow into the crack better, then wrap it; you might want to finish that part of the handle first though
Home of heat-treating, Corbeil, On.  Canada

Marc@Ironwoodbowyer.com

Offline txdm

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Re: Almost done, then pop, creak, crack...
« Reply #10 on: April 24, 2017, 09:33:28 am »
Thanks everyone for the info and advice!

Marc, I noticed the stiffness on the outer limbs too. It came after I heat tempered them with an extra added bit of reflex starting at the midlimb. I was planning to fix it and get the bow down to 40lbs at 26, but I stopped because of the crack.

Later on I'll remove the handle billet and glue that crack and try to fix it.

For now, I'm going to set this one aside and start a new bow in its image, but with 2" fades and a full width handle billet.

I definitely learned a ton, as usual.  8)


Offline Knoll

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Re: Almost done, then pop, creak, crack...
« Reply #11 on: April 24, 2017, 12:21:29 pm »
I definitely learned a ton .......

= success!       8)
... alone in distant woods or fields, in unpretending sproutlands or pastures tracked by rabbits, even in a bleak and, to most, cheerless day .... .  I suppose that this value, in my case, is equivalent to what others get by churchgoing & prayer.  Hank Thoreau, 1857