Author Topic: Boiling Hickory  (Read 1186 times)

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Offline ShorterJ

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Boiling Hickory
« on: May 22, 2022, 05:16:21 pm »
The recurves I boiled didnít stick how I wanted them to, so I re-boiled and still have one side clamped in the form.  I want to use a heat gun to get the curve to stick, but I am also worried the wood is too wet and will split since the first time I boiled them one end started to check within several hours after bending.  Has anyone had any experience doing this or something similar? 

Offline Pat B

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Re: Boiling Hickory
« Reply #1 on: May 22, 2022, 05:30:30 pm »
Seal the back with Shellac before boiling. Shellac isn't affected by the heat and moisture and will help prevent checking.
 You can add an underlay to support the recurves if they want to pull out. Looks cool too!  ;)
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline ShorterJ

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Re: Boiling Hickory
« Reply #2 on: May 22, 2022, 05:36:31 pm »
I used shellac and about half of it boiled off.  I guess I need to reapply shortly after bending.

Offline Stixnstones

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Re: Boiling Hickory
« Reply #3 on: May 22, 2022, 05:56:10 pm »
How long are you leaving it in the form? I leave mine over night before removing from the form, rinse and repeat

Offline ShorterJ

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Re: Boiling Hickory
« Reply #4 on: May 22, 2022, 06:18:39 pm »
The first time I only left them in until they were no longer hot, but the second time I left them close to an hour and they were completely cool.  I wanted to get them out of the form before the wood started to check which had already happened unfortunately.  Maybe I should try steaming instead?

Offline Will B

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Re: Boiling Hickory
« Reply #5 on: May 22, 2022, 07:26:00 pm »
I steam bend my hickory recurves and always shellac the back (as Pat B recommended) and steam for 40 minutes. I keep them 1-inch wide and 1/2Ē thick. I always leave them in the form overnight. Iíve never had a problem with the recurves pulling out. Good luck

Offline superdav95

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Re: Boiling Hickory
« Reply #6 on: May 22, 2022, 11:54:26 pm »
What will b said and pat b said.  Only thing Iíll add is that I would also do like stick said and leave in the form overnight.  Also I do little thicker then 1/2Ē between 1/2Ē-3/4Ē  and keep belly side to single growth ring to prevent lifting when you bend. You can thin out later.   I prefer to boil mine for 35-40 mins then right into the form.  Steam works too.   I donít shellack mine but I do use a poly when sealing the stave back to let it season and dry. This prevent checking for me.   Iíve had good luck with this method.  After letting it sit in form overnight and acclimate some I set it with heat gun to keep the recurve.  Hope this helps. 

Offline ShorterJ

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Re: Boiling Hickory
« Reply #7 on: May 23, 2022, 01:09:11 am »
Thank you all very much for the replies.  Hopefully I will have better success the next time I do this.  The other problem I have discovered is that each end has a large crack from the center to the back of the bow after I bent them.  It looks like a drying check but Iím assuming itís just from too much compression during bending. These cracks appeared shortly after I bent the curves, so I wouldnít think they could be from drying?

Offline bownarra

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Re: Boiling Hickory
« Reply #8 on: May 23, 2022, 01:44:27 am »
Any check like that is due to drying incorrectly.
Boil them underwater.
No need for the shellac - boiling steaming actually reduces the moisture content but in a reasonably controlled manner. you can steam boil completly green wood with no problems. don't worry about that part of it.
Belly worked to one growth ring in essential.
As is making them thin enough. 1/2" on the limb edges is plenty - in fact probably a little too thick. The thicker the wood the more heat and stress needed.
you only need to leave them on the form until the wood is cold.
Dry heat afterwards makes no difference if you bend them correctly first time around.
If they pull out either you are far too thin at the tips or you simply didn't get the wood hot enough. the latter is your issue combined with not enough patatince when the bow was in the form.
Remember it isn't the surface of the wood I am talking about here with regards to heat/cooling - it is the middle of the stave that matters :)

Offline BowEd

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Re: Boiling Hickory
« Reply #9 on: May 23, 2022, 08:36:20 am »
I do much like those who commented earlier.
To me that little bit of checking in your picture won't be a problem.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline gutpile

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Re: Boiling Hickory
« Reply #10 on: May 23, 2022, 09:57:41 am »
I got a video posted on my instagram.. I think it made it on here under a boiling recurve thread. I have never had mine check like that.. I boil 15 min per 1/4 of thickness and use a metal band on belly too prevent lifting a splinter.. I leave it on form overnight regardless... I saw where many use dry heat to set curve , but I too would be worried the hickory would check from that especially here in the south as hickory is so hygroscopic on soaking up moisture and it takes its time releasing it. When I leave overnight on form the curve hardly moves back enough to worry about as my curve form is fairly radical to start with.. I am building the hickory recurve now that I boiled in the video. It is about to hit the tree. After boiling I have to put the bow in a closet for about 6 months to get it back to where it needs to be in MC.. Hickory is a pain in the butt down south but if treated right and watch the moisture content  it will make a bow as good as osage.. the check you have isn't going to be a problem especially if you put on overlays... wish I could post the video here..gut
to take from nature the materials needed to take from nature the meat needed...they all die from natural causes osage, rivercane, stone points,...

Offline Gimlis Ghost

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Re: Boiling Hickory
« Reply #11 on: May 23, 2022, 07:14:00 pm »
One of my first jobs was with a factory that produced "Bentwood" furniture. I didn't work in that section but IIRC they bent the wood by steaming the inside surface of the bend which caused the wood fibers to swell in turn causing these fibers to become shorter as they increased in diameter.

Since the bent sections held their shape for decades of being placed under lheavy oads and flexing a bit I think the process might be suited to recurved wooden bow limbs. I expect the species of wood would be the deciding factor.

Offline ShorterJ

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Re: Boiling Hickory
« Reply #12 on: May 23, 2022, 08:03:46 pm »
The stave should have been dry but who knows.  It was cut over a year ago and has been roughed out to 1/2 inch for several months as well as smoked over a fire overnight and stored inside.  I boiled mine for an hour. It was 1/2 inch thick and 1.5 inch wide. I used a metal backing but later found I didnít need it and never popped a splinter.  As for the crack in the ends I noticed them as soon as I took them off the form, and I took them off the form when they were cool to the touch instead of leaving overnight.  The wood still feels very wet hours after bending.

Offline Hamish

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Re: Boiling Hickory
« Reply #13 on: May 23, 2022, 08:19:26 pm »
"as well as smoked over a fire overnight ". For steaming wood, air dried is more amenable to taking a bend. Kiln dried or force dried, like smoked over a fire removes too much moisture, reduces chance of success for steaming, without degradation.
Guys take a fresh, green, hickory, roughed out stave, to seasoned over night by hanging it quite a way away from a smoking low heat fire.
For KD, or heat treated woo d dry heat is your best bet, though you probably won't be able to achieve radical recurves.

I'd avoid any excessive drying/heat treating in the future, for bending attempts.

Offline superdav95

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Re: Boiling Hickory
« Reply #14 on: May 24, 2022, 01:06:58 am »
Ya I agree with hamish here.  Iíve learned the hard way that you should get the wood down to below 10% mc before heat treating or fire hardening if that was what you were referring to.  I found too that after heat treatment of various types itís very difficult to put curves in without splitting the wood.  The wood changes state and the cells become less pliable.    I do all my curves with boiling the tips prior to any heat treatment and donít have issues.  Get a Mc meter to let you know when you get down to under 10% prior to heat treatment.  Hickory takes heat treat really well and makes great bows imo.  Using seasoned dry wood and letting it dry in the sun after the recurves or flipped tips are put in helps to slowly dry it out safely without checking and splitting.  On more humid days where Iím located Iíll bring the entire form with bow attached inside ac house to get mc down.  Doing it this way will avoid most of your splits when heat treating over fire.  Thereís lot a good info on here about heat treatment of white woods.  Best of luck.