Wood cells are held together by a naturally occurring
substance in the wood called lignin. Imagine the wood
fi bers to be a bundle of rods with the space between
them fi lled with lignin. The strength of this lignin
bond between the rods can be decreased by subjecting
the wood to steam. With unpressurized steam at 212°
Fahrenheit, steaming for one hour per inch of thickness
(regardless of the width) will soften the bond enough for
bending. Substantial oversteaming may cause the wood
to wrinkle on the concave face as the bend progresses