scorched side in bender

[Carl Dickinson]

I've used aluminum flashing from HD for the slats (which is now that third layer) but went back to galvanized steel flashing for its rigidity (it evens out my molds). They retain some of the side's shape but I run them over the corner of my bench to straighten them out before each bend (same with the aluminum slats).
Whether you wet the wood or not depends on the species. When I tried to bend Bocote before, I wet it down pretty good and both sides cracked. I called the vendor to replace them (Aaron Hix), he suggested to bend it dry (still wet the paper) and it worked fine. Quilted Maple had a 24 hour soak in SSII and worked fine. The problem with Afrormosia was major springback for both sides and binding so I guess I'll let it cook and cool longer. Walnut, Hog and EIR had a quick spray, bent fine.
I clip the ends of the sandwich together with spring clamps and remove them as the bending progresses. When it starts to steam (225-240F), bend the waist to almost tight (leave @ 3/8"), upper bout, lower bout (or visa versa), finish the waist (needs to be done before you run out of steam) and let it cook at the target temp for @7-10 minutes. Then cool for 45 minutes. Then if you want, cook for 30 min more and leave it in the bender to cool overnight, but I'm usually too impatient and start on the second side right away.
Notice the paper is not wrapped around the sides.
I'm using a router control to control the heat. I put it full on until bend is complete and then +- 2/3 on the dial until cooking is done. I usually fiddle with the dial per what the thermometer reads..would like to get more accurate with that. Peter, your bender control would be a nice addition.

[peter havriluk]

I agree about how nice a digital controller is. It's a pleasure to watch the temperature cycle no more than two degrees around the 300 I told it to hold. I don't know how much it matters to the wood, but I'm happy watching the show.

[Carl Dickinson]

Well it all went OK... There's still some springback in the Afrormosia but spreaders and clamps should control it. Bocote came out fine. I like the Windex, seems like a good +. Temp control was still problematic but I can live with the results.
The Afrormosia is for a parlor size for one grandson, the Bocote for an ABG for another.
I wish I knew how to take better pictures of the stuff I've made...........