"John Stewart"
Phil Allison wrote:

** Beware - anodised aluminium is an INSULATOR !!!

Any areas to be used for grounding will need to be SCRAPED bare first -
a
real PITA.

One of the summer jobs I had while still in high school was running the
anodizing machine at DeHavilland Aircraft near Toronto. The drop off wing
fuel
tanks for the Vampire (DH110) jet fighter aircraft which first flew in
Sept of
1943 were all anodized in a large tank of Chromic Acid. The whole thing
was
powered by a motor /generator set up. When first turned on the DC current
to
the bath was very high but as time progressed the voltage had to be
increased
to maintain the current. Eventually the wing tank was finished & lifted
out for
rinsing in water, then dried. As Phil has noted, anodizing results in a
very
thick layer of high resistance on the surface of the Aluminum (Aluminium).



** That is one hell of a coincidence JS !!!!

One of my customers, here to pick up his EV 'Entertainer' yesterday, was
telling me how he worked at Hawker DeHavilland's facility at Bankstown in
Sydney - on Vampires !!!

The front fuselage was made of plywood and covered in fabric - which as a
lad he painted with many coats of silver paint to help make it look like
alloy !!





................ Phil