Summary:

1 - Bending Strength: Fir is 23% stronger than Spruce

2 - Elasticity: Fir is stiffer than Spruce (no % mentioned)

3 - Compression Strength:

a. Parallel to grain Fir is 39% stronger

b. Perpendicular to grain Fir is 55% stronger

c. Not only is a Fir spar stronger, but the bearing strengths of bolts in Fir

are higher by the same percentage

4 - Fir is 23% stronger than Spruce but weighs about 26% more

When choosing Fir look for VERTICAL grain that is from 8 to 14 grains/inch in 15"

uploads/20070918_060821_DougFirVsSpruce.pdf