Heat treating a limb?

[snag]

Do you have to use olive oil or something on the limbs when heat treating them? I understand this helps to retard scorching the wood. But if you are slow and easy about this do you have to use oil? I have an osage limb that needs to be brought back to level or slightly reflexed. So yesterday I got the heat gun out and spent some time on it and then clamped it down. It helped quite a bit. But I will have to do it some more to get the results I'm looking for. I also need to build a caul. I just clamped it to a 2X6.

[sailordad]

if your using dry heat to adjust the wood or bend it
then i would recomend using it (not saying you have to)
it helps spread the heat more evenly,does help prevent scorching the wood
i have never actually used heat to treat a limb,but i believe you want the wood to scorch for treating
i have bent and adjusted wood with heat and always use crisco
it smells like french fries 

[osage outlaw]

I used to use cooking oil when heating a limb.  I didn't get all of the oil out of the wood before I sinewed a bow one time and it pealed up in a big sheet.  Since then, I don't use any oil and haven't noticed a difference.  Like you said, I just go slow and keep the heat gun moving so I don't scorch the wood.  With osage, once it starts to get hot, I like to keep pressure on the limb with my free hand.  You can really tell when you hit the correct temp, because the wood will just start to give and bend how you want it.  Then I clamp it down.

[Thomas]

The consesus seems to be to use oil  when using dry heat to bend wood, but some also lightly spray the wood with water when heating. I am going to be using dry heat for the first time on a hop-hornbeam bow in the very near future, and would like to also know whether to use oil or water. I am just adding some slight reflex. I've always wondered if the oil used when heating will affect the finish or not. When we were kids, we used to bend the blades of our hockey sticks over the stove without water, etc. If you saw smoke, it was ready to bend. If you saw fire, too late.

[sailordad]

thomas, if your gonna bend hhb
then i would use crisco or something
it takes heat well,but he oil/lard/grease whatever will help spread it evenly and helps the heat soak in
once your done heating/forming/cooling the stave and its rehydrated some
take acetone or the like and degrease it
do that a few times and the grease/oil/lard should be gone
its always worked for me

i like hhb and heat,works nicely to get the wood to move 

[Gordon]

I don't use anything when tempering a belly - just the heat gun.

[Pat B]

When I'm correcting wood I use oil and dry heat. When tempering(heat treating) I do not use oil and intentionally scorch the belly wood to increase the compression strength and to help hold added reflex.

[Pappy]

I use oil on most heat straightening with white wood,I rarely ever do with Osage unless I am making some kind of really hard bend,like flipping the tip or something. I never use Olive oil,it will work for sure ,just to high for me,I use it to cook and cheap vegy. oil to bend wood.    
   Pappy

[Thomas]

Thanks for the replies gentlemen. The Hop-hornbeam that I am currently working on has about 2" of natural reflex in it already. I am going to heat treat it just to keep this reflex as is. There are also a couple of minor bumps that I will straighten out. Also as a side-note, this stave has a bunch of lines of horizontal bumps,that I'm sure were put there by Downy woodpeckers. Most of the Hop-hornbeam around here in Ontario has these.I hope this will not affect the tension strength of this bow. Don't ask me why a woodpecker would pick on a Hop-hornbeam.

[sailordad]

Don't ask me why a woodpecker would pick on a Hop-hornbeam.

he likes a challenge