My shop recovers very old aircraft and aircraft parts. Some of the aluminum
parts for DC-3/C-47s are dating back 60+ years old. The aluminum that was
zinc chromated are still holding up well and when we strip them, we replace
the zinc chromate. Even though the military also wanted the steel parts
chromated along with the aluminum, we can clearly see that the chromates
don't hold up as well on the steel. For these we have gone to epoxy primers
instead. A small company in St. Louis by the name of Walter Wurdack Co.,
Inc. is our shop's supplier for chromate at a very fair price compared to
auto supply and etc.

A side note for the curious. Those fabric installers that used medical
cloth tape as anti-chafe, holds enough mositure to cause corrosion between
the rib and fabric. The old masking tape is so thin and waxy that it
apparently will not hold enough moisture and we have never found any
corrosion over the hundreds of Be-18/C-45 and DC-3/C-47 flight controls that
we have recovered over the years. Of course, we've seen every thing from
flour sacks, scotch tape, electrical tape and aluminum foil used. I hope
this is the kind of information that you were wanting.
Robert Little
Razorback Fabrics, Inc.
"aa" wrote in message
...
I am in the process of restoring a Cessna 170. It is a major restoration
with many fuselage and wing skin pieces being replaced. How should I treat
the interior surfaces? I initially planned to paint everything with zinc
chromate. But the more I look into this, the more I worry about the
toxicity of the zinc chromate and the lack of effectiveness in terms of
corrosion proofing. I've heard of folks using self-etching primers, wash
primers, epoxy primers, nothing at all, or even spray can enamels.
What would you recommend?
Thanks,
Alex
N170W
Cessna 170B