The Forestry Forum

customer wants 7/8  - 15/16" final finished size in Pecan lumber.

Is 1 & 1/8 or 3/16 plenty for rough sawn thickness?

I would go at least 1 3/16" thick.  Pecan likes to cup, and it likes to dry in waves where it kinks at the knots.  I generally cut it 5/4 thick, 1 3/8" rough, so that I can get a full 1" thick finished.

When you cut 1.125", this is the average and there is variation.  So the thinnest piece or spot is likely 1.035".  Then there is a maximum of 8% shrinkage, but most are less. It would be rare that the thinnest piece is also the maximum shrinkage, so we will use 7% shrinkage in drying to give us the thinnest piece of 0.91".  Now, add for cup (?) and planer allowance (0.03).  Recalling that all pieces are thicker than the minimum, we do not need a big allowance for cup usually, especially with good drying.  So, final planed size is about 0.87".  Do your own calculations.

My pecan dried exactly as Danny described.  It was in waves about every 16".  Luckily Andy sawed it thick enough that when I skip planed it, it was still 1".  Final planing by the guy who bought it was gonna be more like 7/8 when said and done.

i'll share this info with the customer and suggest..... 1 3/8"

thanks all!