Susan re. "Shear"

[Ron Nossaman]

>It's obvious to me that you do not understand the word "Shear". Shear is any
>direction. It just depends on what plane it is in. In the case of bridge
>pins/bridges it is horizontal shear or sideways shear. Get it?
>
>Joe Garrett, RPT, (Oregon)

A force perpendicular to a plane produces stress at the interface between 
the acting, and the acted upon. A force parallel to a plane produces a 
shear stress at the interface between the acted and acted upon. Any benefit 
of CA around bridge pins in an otherwise structurally sound bridge is in 
increasing compression resistance of the wood and filling the gap on the 
compression side of the hole. It soaks into the fibers and reinforces them. 
It also is a reasonably decent gap filler under compression (as long as 
it's contained), which is, again, what it does in a bridge. CA's shear 
strength has no bearing whatsoever on it's suitability for this use, since 
there is no demand on the glue at all for shear strength. It's relatively 
poor shear and tensile strength make CA a bad choice for repairing split 
bridges, in my opinion, but there still ain't no shear on a CA glue joint 
in an un-split bridge pin hole that is of any consequence to the 
suitability of the choice of CA for the repair in the first place, no 
matter who arbitrarily says that shear is any stress in any direction.


Ron N