On Tue, 09 Aug 2005 21:27:29 -0500, "Dan, U.S. Air Force, retired"
wrote:

wrote:
This was a standard procedure on many early Fokker & de Haviland-type
fuselages (ie, plywood shear-web & wooden structural members), although
most were chamfered rather than routed. While there is some reduction
in weight, knocking off the corners reduces the surface area of the
exposed portion of the structural member, requiring less varnish.
Elimination of the corners also reduces the tendency for brashness or
splintering common to Douglas Fir.

In a similar vein, that odd green tint seen in the varnish on the
inside of early wooden airframes came from an anti-fungal agent, added
to the varnish to prevent the biological degradation of the
casein-based glue.

-R.S.Hoover

Aresenic or copper?

Dan, U.S. Air Force, retired

Copper