Steam curving question: How long in clamps?

[WhistlingBadger]

Title says it.  I'm planning on steaming some recurves into a juniper bow this weekend.  I only have one form, so I'd like to steam the other end while the first is cooling off in the form.  Can I take the bow out of the form once it's cooled off, or do I need to leave it in the clamps for hours/days/weeks/decades?

[superdav95]

Title says it.  I'm planning on steaming some recurves into a juniper bow this weekend.  I only have one form, so I'd like to steam the other end while the first is cooling off in the form.  Can I take the bow out of the form once it's cooled off, or do I need to leave it in the clamps for hours/days/weeks/decades?

I’ve not made a juniper bow yet but with yew I just let it cool off for about an hour.  Then steam and bend other side.  I’ve not had them change shape on me with this method.  I’m sure you could let it cool off and then move to other side and be fine.  Let it acclimate for a couple days before setting the curves with heat gun.  When I’ve rushed this step too soon I’ve gotten cracks.  Best of luck. 

[WhistlingBadger]

Thanks, Dave.  Tell me about "setting the curves with a heat gun."

[Hamish]

 Steam bending allows more plasticity than dry heat, safer to achieve radical bends. Wet heat doesn't have the same tempering ability as focused dry heat. Therefore dry heat after wet gives you the best of both worlds.

[Hamish]

Regarding clamping time, leave clamped until the wood returns to room temperature. Not the surface but the core of the wood, it retains heat for quite a long time.

If you are in a hurry and really wanted to reduce clamp time, you could wait until the wood is safe to touch for extended periods of time. Then you could place ice packs, or even hose it down to cool it off rapidly.

[bownarra]

1 hour is enough. No need for the dry heat afterwards. You will always get some spring back dependant on the bend you are trying to make, the wood species etc...
The best tip I can give you regarding bending recurves is boiling water is better than steam
then one ring on the belly, not too thick, edges rounded over, reduce the width where you want the bend concentrated, leave the tips full stave width etc the list goes on

[mmattockx]

reduce the width where you want the bend concentrated, leave the tips full stave width etc the list goes on

I like this idea, great tip. It lets you force the bend to occur where you want it and nowhere else without a lot of effort clamping things to keep them straight. 


Mark