Author Topic: Heat gun bending?  (Read 22666 times)

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Offline nclonghunter

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Heat gun bending?
« on: January 21, 2011, 07:20:51 pm »
I'll bet this has been covered, but not a difficult answer, I hope.

In order to heat a bow limb into a reflex on a form, it would be clamped on the form and the limb would be straight out above the curved form?  Then begin heating the limb (belly) and slowly bend it into the position desired clamping in place ?
Some of the bending photos I have seen appears like the limb is clamped down to what you want the finished limb to look like and then heated. I am afraid that would break the limb if not heated as you go.
I know from doing that when steam bending, the limb is steamed first and then bent, then allowed to dry and stiffen on the form.

I just bought a heat gun and realize if I tried it before asking this question, I would probably know the answer, but with all the experience on here maybe you guys can show me the best way. 

Thanks for the help and guidance.
There are no bad knappers, only bad flakes

Offline bcbull

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Re: Heat gun bending?
« Reply #1 on: January 21, 2011, 08:52:17 pm »
WHAT KIND  WOOD YOU BENDING  ?  I APPLY VEG OIL TO THE WOOD   THEN HEAT IT  THEN START TO BEND  IF UR WOOD S DRY HEAT GUN IF GREEN USE STEAM  BROCK


Offline nclonghunter

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Re: Heat gun bending?
« Reply #2 on: January 21, 2011, 09:37:54 pm »
I will be bending 2 bows,, Osage and hickory and both are dry...does the wood actually get soft and flexible when heated with gun...I suppose you can test the stiffness before heating then keep trying it until it begins bending easily, will it get that soft.  I do not want to over heat it and burn the wood, just get it to the right temp. I will use the veg oil for sure. Thanks for your help Brock.
There are no bad knappers, only bad flakes

Offline sailordad

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Re: Heat gun bending?
« Reply #3 on: January 21, 2011, 11:41:16 pm »
never tried doing more than taking out some twist with hickory
but sage will get flixible like a piece of licorice when it gets to a good bending temp
atleast that my experience  ;)
i always wanted a harley,untill it became the "thing to ride"
i ride because i love to,not to be part of the crowd

Offline bcbull

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Re: Heat gun bending?
« Reply #4 on: January 21, 2011, 11:49:17 pm »
TIM S RIGHT OSAGE WILL BEND LIKE A WET NOODLE  I LOVE BENDIN OSAGE  HICKORY IM NOT SO SURE THEY SAY  DRY AND PROPER MOIUSTER CONTENT HICKORY BENDS WELL WITH DRY HEAT  TRY A SCRAP AND SEE TIM KNOW S MORE ABOUT HICKORY THAN I DO IV WORKED VERY LIL HICKORY  BROCK

Offline JW_Halverson

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Re: Heat gun bending?
« Reply #5 on: January 22, 2011, 12:10:06 am »
When the wood "plasticizes" it definitely gives way easier, it really happens quickly, too.  I usually keep the heat gun moving with one hand and give little test pushes with the other.  It keeps it's resistance for quite a while but then all of a sudden gives up.

When it starts losing resistance, I keep heating for a while longer and then do the bend and clamp it quickly.  Helps to have the clamp right at hand and set up so that it takes just a twist to lock it in place.  Remember to pad all surfaces so that the wood doesn't take a crease from a sharp edge.  Those creases are a death sentence without a parayer of the Governor calling with a pardon!
Guns have triggers. Bicycles have wheels. Trees and bows have wooden limbs.

Offline nclonghunter

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Re: Heat gun bending?
« Reply #6 on: January 22, 2011, 12:02:28 pm »
Thanks guys, I had no idea it would get that soft and flexible, Can't wait to give it a try!
There are no bad knappers, only bad flakes

Offline Pat B

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Re: Heat gun bending?
« Reply #7 on: January 22, 2011, 12:39:27 pm »
When I use heat to bend recurves in osage I clamp the tips in the form with the rest of the bow pointing up at about a 45deg angle, coat the wood with cooking oil and heat until gravity begins to pull the wood down. I then bring it down to the form, making sure it is alligned OK then clamp it. Osage especially becomes  "plasticised" when heated and bends quite easily.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Grunt

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Re: Heat gun bending?
« Reply #8 on: January 22, 2011, 03:35:27 pm »
Do yourself a favor and do your first bend on a practice piece. It takes a while to have the heat sink into the center of what ever wood you are bending. Oil or lard helps a lot. Go slow. Have fun.

Offline artcher1

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Re: Heat gun bending?
« Reply #9 on: January 22, 2011, 04:19:27 pm »
You can dry heat and steam at the same time. Just get your wood hot and spray with water. Keep heating and steaming until you get the desired effects. No messy oils to clean up.......Art

Offline eflanders

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Re: Heat gun bending?
« Reply #10 on: January 22, 2011, 09:00:45 pm »
I usually use a weight on the end of the board and let gravity bring it down onto the form.  This ensures that the core temperature has reached the appropriate point and I don't try to force it before it is ready to bend.  Also it tells me if it I have the heat too close or too far away.  If the heat source is too close, the wood scorches before bending.   

Offline Carle1953

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Re: Heat gun bending?
« Reply #11 on: January 27, 2011, 07:57:05 pm »
I agree with the guys on clamping the tip then heating until she starts to bend by weight alone.  I use a 10" crescent wrench for just a little weight.  I also use olive oil on the stave so that it will not dry out or scorch.  When I first tried heat bending osage I tried to force it. Not a good idea, it popped the grain on the back in a few spots. I used slow set superglue to glue them back down, so far they have held.  I will tell you however that I was really worried that I had destroyed the bow.  Take your time.  I usually heat mine in about a 4-6 inch area until it is too warm to hold my fingers on, take a break, have a smoke, and come back and heat again.  I find it is a lot easier to take my time than to start over with a new stave.  Every stave has lessons, some make it to a bow and others are just lessons. Good luck, if you aren't making mistakes you aren't making bows.

Offline Catahoula

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Re: Heat gun bending?
« Reply #12 on: January 27, 2011, 08:43:20 pm »
Hi,

Same way with iron wood?  And this is done after final tillering and such...right?

Rand
“You only live once, but if you do it right, once is enough.”― Mae West

Grunt

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Re: Heat gun bending?
« Reply #13 on: January 27, 2011, 09:17:47 pm »
I've been covering my bending form with tin foil. Seems to reflect heat back into the bow instead of loosing heat into the form by heat sink effect.

Offline Pat B

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Re: Heat gun bending?
« Reply #14 on: January 28, 2011, 12:30:03 am »
I use foil too on thicker wood. I'll heat it for a while, wrap it in foil for 5 minutes or so and heat some more. Give the heat a chance to get deep into the wood. Be careful of the heat flashing off the foil and scorching the bows back. Don't ask!  ::)
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC