it was in the news letter, i have the snipet...HARD SHELLING
Hard shelling is a procedure (not recommended) of
covering foam with micro, letting it cure, and sanding the
surface prior to covering it with fiberglass.
Paul Kuntz, a Boeing engineer presently stationed in
England, did some experiments which he reported on the
internet 09/01/01. His conclusions were:
“After doing some two-layer uni layups over the hardshelled
sample surfaces, I attempted to peel the layups from
the foam to see how well they had bonded to the hard shell. I
found that where the hard shell was merely filling the usual
roughness in the foam surface, the glass remained bonded to
the hard shell and what failed was the foam beneath. That is, I
was breaking the foam itself when I stripped the glass… ..The
bad news was that everywhere the hard shell had filled in a
void, even as small as one-eighth inch in diameter and perhaps
one-sixteenth inch deep, and everywhere the hard shell had
been used to create even a very thin filler layer on top of the
foam, the glass skin popped right off the hard shell as clean as
a whistle… … Scary!…
My advice has been, and continues to be, stick to the
plans................