I am building two tenors that will have curly maple sides. I love the look, I love the sound, I hate the bending.
Curly (aka tiger stripe maple) is beautiful because its fibers undulate in unceasing waves. The problem is when you thin it down, thin enough to bend many of those fibers are severed. The darned stuff is really tough to bend without breaks and cracks, Here is my evidence.
Curly (aka tiger stripe maple) is beautiful because its fibers undulate in unceasing waves. The problem is when you thin it down, thin enough to bend many of those fibers are severed. The darned stuff is really tough to bend without breaks and cracks, Here is my evidence.
The first side came out perfect. Then disaster struck. The next two efforts resulted in this complete break and an ugly crack. Fortunately I had prepared for this and had made a bunch of sides to bend. I figured if they were all successful I would have lots of sides stored up for the future. I got off three more good ones in a row and figured I had it made, then the next two came out cracked. the problem is in that acute bend at the upper bout. The waist and the lower bout never give trouble but that little bout with the tight turn is murder. Maybe I made these sides a little too thin. I sanded them down to .70.5.
Anyway here is my process
Anyway here is my process
 Wet a strip of paper |  Wet the wood- |
Then wrap the wood in the paper and wrap the wet bundle in aluminum foil. Place it on a stainless steel bending strap, place the heat blanket on top-and on top of that place a second steel bending strap
Now place the sandwich in the bender and tighten the waist screw slightly while the heating blanket heats up
Place a surface thermometer on the package and when it gets to 300 degrees start to slowly tighten down the waist. By the time it is all the way bent you will be at 350 degrees and it is time to bend the bouts.
Slowly bend the lower bout downward. You can feel the wood ease and quit resisting as you press down with a piece of wood. Now connect the spring "roller" and use it urge the wood to its curved position. Leave it held in place by the spring loaded piece of wood.
Now turn to the small bout and very very slowly apply pressure to the steel. Be sure your temp is at least 350. When you have bent it all the way secure it with the spring clamp and turn off the heat.
Let the temp. slowly go down to about 100 degrees- Now you can undo all the machinery and see what you have got. Cross your fingers!!
Slowly bend the lower bout downward. You can feel the wood ease and quit resisting as you press down with a piece of wood. Now connect the spring "roller" and use it urge the wood to its curved position. Leave it held in place by the spring loaded piece of wood.
Now turn to the small bout and very very slowly apply pressure to the steel. Be sure your temp is at least 350. When you have bent it all the way secure it with the spring clamp and turn off the heat.
Let the temp. slowly go down to about 100 degrees- Now you can undo all the machinery and see what you have got. Cross your fingers!!
This looks pretty good-lets unwrap it and see what we have
Great ! a perfect side. I only wish they were all like that
 The good sides are put in a device to hold their shape as they dry and cure. Here is one way to do it |  Here is another. I will leave them over-night as I will be needing these drying molds tomorrow for a few more maple sides and the East Indian Rosewood which I expect to be a great deal easier to bend. |
I made myself some notes on the side of the bender. It is easy to forget the order of the bending "sandwich" if you do it only every couple of months.
