Author Topic: hot box heat bending?  (Read 2986 times)

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Offline osage outlaw

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hot box heat bending?
« on: August 07, 2014, 09:29:46 am »
I was working on an osage bow and was ready to put it on the caul.  I put the bow in my hotbox for a while to pre-warm it before I put the heat gun to it.  When I took it out and started putting it on the caul I noticed that it felt slightly pliable like when you are almost ready to make the heat bend.  It made me wonder if you could heat a bow up enough in a hot box to take it straight to the caul and bend it without using a heat gun, or at least do most of the bending and use the heat gun just to keep it warm while doing the final bends.  Does anyone know exactly how hot an osage bow has to be to bend?  I'm not sure how high my hot box will go.  I can max out a 125 degree thermometer within a few minutes if I want to.  I was kind of thinking this would be sort of like a dry steam for the entire bow.  It would sure be a lot easier to throw it in the box and crank it up compared to setting up the pan of water, pipes, and foil for a steam session.
I started out with nothin' and I still got most of it left

Offline Badger

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Re: hot box heat bending?
« Reply #1 on: August 07, 2014, 09:45:47 am »
  I am pretty sure you could, I used to use a solar hot box where I would put a bow in a form using spring tension or inner tubes and leave it for a weak or so. I could nicely reflex a bow like this. I have often thought about setting a temp for about 240 and letting the bow reach full temp then clamping it. I think it would work.

Offline IdahoMatt

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Re: hot box heat bending?
« Reply #2 on: August 07, 2014, 10:20:26 am »
That's an interesting thought.  Sounds like it would be a good way to do it.

Offline osage outlaw

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Re: hot box heat bending?
« Reply #3 on: August 07, 2014, 04:39:25 pm »
With my current heater I can get the box up to 150.  I have another heater that might get it a little higher.  Or I could use both heaters.  I'm sure that would get the temperature up some.
I started out with nothin' and I still got most of it left

Offline TRACY

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Re: hot box heat bending?
« Reply #4 on: August 07, 2014, 06:15:23 pm »
Sounds doable. You're not far from the temp of steam. I thought about this when I worked at GM using ovens that were 180 f for curing silicone on circuit boards. Experimenting with the time needed to hold at the right temp is all that's left to figure out. Try it out on a stave!

Tracy
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Offline Danzn Bar

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Re: hot box heat bending?
« Reply #5 on: August 07, 2014, 07:51:13 pm »
Yep,................ 212 deg is steam.  when I steam in the static reflex I use the heat gun the keep the wood  bendable.  I think that would be a very clean way to do it Clint.
DBar 
Integrity is doing the right thing when no one is looking

Offline Buckeye Guy

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Re: hot box heat bending?
« Reply #6 on: August 08, 2014, 10:21:08 am »
Clint
it should work fine
I have never blistered my fingers on a stave so 200 degrees should be hot enough since 212 would blister my fingers
so start at 200 and work your way up if needed
Do you have a foil backed insulation in your hot box , if not eventually you will lower the flash point of your wooden box to the point of fire hazard , only mention it because you are going pretty hot and you do a lot of bows so be on the look out
Have fun!
Guy Dasher
The Marshall Primitive Archery Rendezvous
Primitive Archery Society
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blackhawk

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Re: hot box heat bending?
« Reply #7 on: August 08, 2014, 12:20:01 pm »
Fire hazard wood be my concern too....if using an electric heater to heat it up that might exceed the limits of it(call company or research it out what they can take)...maybe find some 1 hour firewall sheetrock ..it'll insulate the box and keep any fire from happening in the box from spreading to other areas outside the box..aka...YOUR MAN CAVE!!! That's wood be a sad day

Offline mullet

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Re: hot box heat bending?
« Reply #8 on: August 08, 2014, 03:19:13 pm »
Should work. I had to move my wooden and bamboo arrows back in the house. My shop was getting so hot during the day that the arrows were bending into whichever way they were leaning.

I do use a hot box for bending but it's a micro wave. :)
Lakeland, Florida
 If you have to pull the trigger, is it really archery?