You're on the right track with the vacuum, but the devcon stuff is
formulated to be a glue, not a clear encapsulation. This means it
isn't built to release trapped air as easily as the epoxies that are
intended to be used for encapsulation. (In the 'no free lunch' file,
those epoxies aren't quite as adhesive as devcon.) Try some of the
Colores clear epoxy from Rio. Use the thin hardener, and vacuum it,
both before application, and after, if the design is such that you
I've done champlive work with epoxies similar to the colores
formulation for years, with good results. My technique is to
radically overfill the cells, then file and grind back to the surface
plane, then polish. I almost never get bubbles....except exactly in
the finish plane. 1mm above the line, nothing. 1 mm below, nothing.
Somehow, it knows. That happens very rarely, but the annoying thing
is it's always in the exact wrong place. Proof of nothing so much as
my personal deity's name is Murphy.
Hope this helped.