Official Luthiers Forum!

I will be bending a cutaway SJ out of quilted Sapele for the first time coming very soon. Im looking for sugestions on bending temp. and pre-heat times. My sides will be .08 thick. I have not bent quilted Sapele before and am a bit conserned about crackng and figure peel. Should I bend the waist or the cutaway first? This will be bent on a fox style bender and a single blanket.

I bent at 300?. Waist first, lower bout then cutaway. I cracked the first set I tried because I went VERY, VERY slowly and I think I seamed out all of the moisture in the wood, making it very brittle. The second set went pretty well, had a bit of figure peel on the horn but they CA glued back down just fine.

   I have been having very good luck with the stuff here is how I bend this
First I use Kraft paper that is soaked in water for about 2 minutes ( 2 pieces )
I do spray the wood much like I am cleaning a window. Then I set the slat wet paper wood wet paper slat and I use a heating blanket on top.
   I let the heat climb to about 300 and check to see that things are still wet and I am seeing steam. Once this happens I will do the lower bout first then the upper bout and then the waist. hold this at about 325 for 3 minutes then let cool.
john hall

John do you start the waist at all before completing your bout bends?
I always drop the waist first, all but the last 1/2" or so, then complete both bouts, and come back and finish the waist.

Also, what kind of thermometer are you guys using and were do you take the temp? Ive never used one, just went by feel.

_________________
Support the OLF! Bookmark our STEWMAC link Today!
Lance@LuthiersForum.com

[QUOTE=LanceK] John do you start the waist at all before completing your bout bends?
I always drop the waist first, all but the last 1/2" or so, then complete both bouts, and come back and finish the waist.

Also, what kind of thermometer are you guys using and were do you take the temp? Ive never used one, just went by feel.[/QUOTE]


Good questions on where to take the temp Lance. I take it one 2" lower bout side of the waist caul. about mid plank in other words. I use a cooking thermometer I got a Wally world seems pretty accurate + or - 5 deg or soMichaelP38677.5234606481

I use a probe thermometer, I place it between the waist and lower bout, in between the blanket and the top slat.

I put it under the wood, if you put it between the blanket and the wood you will be reading the blanket tenp and not the wood.

    I bring the waist cawl down just a tad before I bend for friendly friction so I can do my aligning. Once the set is in the bender I won't touch the waist cawl until the bouts are in place. This way as the waist cawl pulls into postion the ends are under tension and the woods falls onto the pattern better.
   I use a regular cooking digital thermometer . I like the one with the probe and will start with it under the blanket and top slat , then once I hit 250 I set it at the waist between the steel at an empty spot. Never place the probe on the wood as you will let a mark that takes forever to sand out.
   I have notices that the 275-300 will hold easy but once the water boils off the temp spikes so keep the spray bottle handy
john hall