Removing bends with dry heat

[justsomedude]

Once you see the wood give in to bending, how long do you need to keep it hot?
I'm doing some lateral bending and prop twist using weights. I can see the weights sag as the temp gets up.

[Dances with squirrels]

Depends. I do it like this...

determine how far it needs moved,

add the weight,

take a measurement to the floor, bench, ceiling, etc for a starting point.

prop, stand, hang the tape measure in place so I can watch/gauge the limb's movement as I heat it and the weight and heat affects movement.

allow it to move 5% farther for springback

cool

remove weight and check

To more specifically answer your question.... once you see the movement you need, including springback, no more heat need be applied.

[justsomedude]

Got it. I am watching the Gary Davis DVD. He steams it for 2 hours in a stove pipe and then takes it out and clamps it. I plan to build myself a slight refer form soon.

[Del the cat]

BIG difference between time needed for steam and dry heat to penetrate.
Steam is 100C dry heat is about 200C
If used the 'magic brick' pulling down on a limb as it's being heated and seen the wood start to move in less than 5 minutes with dry heat, where steam would have needed at least 30mins.
Del

[Dances with squirrels]

If the blank's limb areas are less than an inch thick, one hour in the steamer is generally enough. The only time I left it in there for two hours is when I went in the house and forgot about it :^)

[bjrogg]

I usually use dry for smaller corrections and steam for bigger bends. Steam works great but make sure you have everything ready to clamp down. Once you remove from steam you have limited time before it cools and sometimes it's hard to have enough hands. Also make sure you don't run out of water, the longer you steam the more water you need. If you have to add some you end up starting over.
Bjrogg

[George Tsoukalas]

Here's how I move propellor twists.
http://traditionalarchery101.com/fixtwist.html
Jawge

[bushboy]

I swear by Marc's localized steam method!from corrections,recurves ect!

[willie]

tried some dry heat recently for making adjustments, and thought it might be a good idea to preheat the whole limb area some before hitting it with the gun. Put it over the wood stove top for a while, and it seemed to lessen the time needed with the gun, but I got concerned about how warm or dried out the back was getting (I worked the gun from the belly side).

Anyone ever use steam to preheat and then use the heat gun to raise the temps more?

[DC]

Not so much for pre heating but I steam bend and then "lock in" the bend with dry heat. I have no idea what's actually happening in there.

[Stick Bender]

I have been wrapping my stave in a electric blanket and bring the wood up to 130 F for a couple hours before using the heat gun works out well for me less heat gun time .