Heat treating cracks

[paulsemp]

I too have the same problems once in awhile. I can never seem to put my finger on the cause though cuz there's always so many variables. I have noticed or at least I'd like to claim that certain batches of Osage are more prone to this. And other batches I've had never seam to get a crack. Obviously moisture plays a big part in it but I also believe that where it was grown and possibly mineral content or whatever else makes up wood may have something to do with it. I guess that's one for the scientists. One thing that does help me is slower preheat. Now I'll keep that gun moving up and down that limb for a good 12 inches at a time before I start dumping real heat into it. Sort of the same concept when your welding heavy metal or cutting with oxy fuel. Preheat has helped me but sometimes it does nothing. Sorry Clint not much help here

[osage outlaw]

That was helpful Paul.  Now that I think about it, the bows that have cracked the worst have been red osage.  The bows from the more yellow colored wood have had less cracking.  And I try to move the heat gun down the limb to preheat it like you said.  I reflex it and temper it at the same time.  On the next one I think I'm going to reflex it on the form and then wait a day to come back and temper it while its still clamped down.  I'll see if that makes a difference. 

[mullet]

I use Crisco everytime I dry heat bend and never had a problem with cracks. If I add snake skins I just "wash" it in acetone before I glue them.

[riverrat]

when you heat it use oil.you wont have cracks.Tony

[Aaron H]

That's what I use mullet, Crisco

[osage outlaw]

I don't have problems with cracking during heat bending.  I'm getting cracks during the tempering.

[PEARL DRUMS]

I've seen PLENTY of oil slathered cracked bows. Its not that cut and dry. Pardon the pun

[Pappy]

I have had it happen from time to time, mostly on fairly new wood 1 or 2 years old. I do usually seal the back and sometime use cooking oil on the belly, still happened from time to time. I don't usually heat temper Osage but have had it happen when it needs some heavy corrections. 
 Pappy