Primitive Archer

Main Discussion Area => Bows => Topic started by: nclonghunter on January 21, 2011, 07:20:51 pm

Title: Heat gun bending?
Post by: nclonghunter 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.
Title: Re: Heat gun bending?
Post by: bcbull 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

Title: Re: Heat gun bending?
Post by: nclonghunter 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.
Title: Re: Heat gun bending?
Post by: sailordad 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  ;)
Title: Re: Heat gun bending?
Post by: bcbull 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
Title: Re: Heat gun bending?
Post by: JW_Halverson 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!
Title: Re: Heat gun bending?
Post by: nclonghunter 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!
Title: Re: Heat gun bending?
Post by: Pat B 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.
Title: Re: Heat gun bending?
Post by: Grunt 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.
Title: Re: Heat gun bending?
Post by: artcher1 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
Title: Re: Heat gun bending?
Post by: eflanders 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.   
Title: Re: Heat gun bending?
Post by: Carle1953 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.
Title: Re: Heat gun bending?
Post by: Catahoula 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
Title: Re: Heat gun bending?
Post by: Grunt 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.
Title: Re: Heat gun bending?
Post by: Pat B 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!  ::)
Title: Re: Heat gun bending?
Post by: 1776J on January 29, 2011, 11:15:16 pm
So guys,....
seeing this I didn't see anything in direct reference to heat bending Hickory?

Does it work well?  Anyone here ever done it successfully and so on?
I'm curious about it as Hickory was a common wood used by the Woodland Indians of this area and others and you see reflex in them as well as other bows I've seen in a few of the
Traditional Bowyer's Bibles.....
 ;)

Title: Re: Heat gun bending?
Post by: osage outlaw on January 30, 2011, 03:42:31 am
I tried dry heat to put some curve in the tips of a piece of HHB and it cracked the belly fibers.  From now on, I will use steam for whitewoods and dry heat for osage.
Title: Re: Heat gun bending?
Post by: Gordon on January 30, 2011, 03:55:03 am
Outlaw, you pushed the wood too hard. When you use dry heat you need to go slow and easy.
Title: Re: Heat gun bending?
Post by: sailordad on January 30, 2011, 10:26:37 am
I tried dry heat to put some curve in the tips of a piece of HHB and it cracked the belly fibers.  From now on, I will use steam for whitewoods and dry heat for osage.

i agree with Gordon
i have never had hhb do that
not that i have bent all that much of it,but i have done it with great success
Title: Re: Heat gun bending?
Post by: Pat B on January 30, 2011, 11:49:10 am
I have had mixed success bending hickory with dry heat.  Some the wood bent well but it didn't hold once the bow was stressed.   Ideally, if you start with green hickory, shape it to floor tiller stage and steam bend it I think the bends would hold better plus the act of steaming will force moisture out of the wood and aid in the drying process. You will still have to wait a considerable amount of time for complete drying.   I am haveing very good success recurving the tips on a 60" elm static recurve. This wood was well seasoned and so far it has bent well. I won't know how well untill I get the bow finished and a few shots through her. I have very little experience with bending other whitewoods.
Title: Re: Heat gun bending?
Post by: 1776J on January 30, 2011, 02:30:11 pm
Thanks for the reply fellas,...
I just was curious if I ended up working some Hickory what path would be the best to follow.

Now if you had tried heat bending a piece of Hickory and it didn't work well, and wanted to go ahead and steam bend it afterwords, could you still do that or would you run the risk
of damaging the wood fibers, etc?  I'm wondering if there would just be to much stress being put into the limbs at that point,.. (dry heat, steam heat, etc. for the wood to hold up)??

Any ideas?

Thanks guys.
Title: Re: Heat gun bending?
Post by: Pat B on January 30, 2011, 04:24:04 pm
I like to use dry heat with dry wood and wet heat with wet wood. If you wanted to steam or boil dry hickory seal the area to be bent with shellac. It can take the heat and moisture and prevent moisture from entering the already dry wood.
  Here is another option. This is a hickory recurve that the curves pulled out of. I rebent them and added the black walnut underlay to support the bend.
(http://i5.photobucket.com/albums/y199/PatBNC/Hannahsbow012.jpg)

(http://i5.photobucket.com/albums/y199/PatBNC/Hannahsbow008.jpg)

Title: Re: Heat gun bending?
Post by: 1776J on January 30, 2011, 06:15:41 pm
Thanks for the detailed advice Pat,... :)

Makes you wonder, with the recurve pulling out from Hickory,... how did the Indians do it all those years ago with their hickory recurves?
Dry bending over a fire?... steaming it in the fire?... both I presume.

With all our questions,... boy,... makes ya wish Ishi were alive today!
Title: Re: Heat gun bending?
Post by: 1776J on January 30, 2011, 06:25:43 pm
@Pat.....

hey what about sinewing the back,.....would that aide in keeping the recurve in??
come to think of it, many if not all those hickory bows i see in the traditional bowyers bibles of native american origin are sinew backed!!
Title: Re: Heat gun bending?
Post by: eflanders on January 31, 2011, 12:51:29 am
I've dry heated hickory.  In my experience it is not very effective with green wood.  But it does work well with seasoned wood.  The trick lies in how wet the seasoned wood is already and if you use something (like a steel strip) to help prevent it from pulling a splinter. 

First thing to do is to weigh the piece you are bending.  Second, add your heat.  (Natives used to stick the wood under the firepit.) Third, when the wood wants to give easily, wait a little longer if possible to ensure the heat is all the way to the core.  Fourth, bend the wood using a metal strap, clamp them both to the form.  Fifth, remove clamps after it has cooled completely.  DO NOT STRESS THE BEND!  Sixth, weigh your bent piece again.  If the weight is the same, you can now safely begin to exercise the piece.  If it does not weigh the same, wait until it does before exercising it.
Title: Re: Heat gun bending?
Post by: sailordad on January 31, 2011, 12:56:33 am
so if the ancients put their bow wood under the fire pit to heat it for bending
how did they weigh it to know when it was ready for stressing?
Title: Re: Heat gun bending?
Post by: Pat B on January 31, 2011, 01:04:23 am
I believe a lot of Native bows were shaped green and cured after that.  The shaping may have been over time with heat and animal fat to slow the drying rate so the wood wouldn't check.
Title: Re: Heat gun bending?
Post by: 1776J on January 31, 2011, 03:56:18 pm
Very interesting guys,...
very interesting indeed. 
Pat's comments as to the wood being shaped while fairly green reminds me of a comment that Ed Scott makes in the one video on youtube where he speaks of a
piece of Juniper he's bending and shaping in his bow form.... he says its still "green" when he heats and shapes it.  Very interesting correlation between the idea and the idea put into practice.
Title: Re: Heat gun bending?
Post by: FunyFarm on July 16, 2016, 11:45:30 am
Lol now he tells me..  Just put my first heat bend , just thinking it would work.  Now I read this chain,, I know I did my best.  The recurves, were crude and it left marks,  but it is "Primitive" I just used a dark stain to make the whole thing look rustic,  put serial number 0001 on it and go.

It only took me 5 really good try's to get to the point.  I love this forum y'all teach me something every time😊👏👏👏👏👏
Title: Re: Heat gun bending?
Post by: SLIMBOB on July 17, 2016, 03:21:36 pm
I will add, that for me with a heat gun I dont go all the way at one time.  I take smaller bites.  I also have started lightly sanding the belly where I am bending as I go.  It seems to help  stop those nasty tears from happening.