I have a 29 year-old A/C, not hangared, and its aluminum parts inside
the cabin are surgically clean. Only the steel parts are
zinc-chromated, which itself isn't the best (epoxy chromate is much
better; successful on the wingtip aileron counterweight arms, where
the zinc stuff had to be renewed annually). In the rear fuselage,
vented a little to the outside at the tail, only slight traces
anywhere, in low spots.
In reading many FAA Service Difficulty Reports over the years, it
often sees physical forces are the culprit. Aerobatics, banging
against the stops in high winds, and outboard elevator brackets
contorting in the propwash. Corrosion aggravates, of course, hence
prevalent in places vented to outside contaminating air. And Nevada
is one place, salty coastal states another.
IME, painting (esp. a lighter color) can even assist in visual crack
detection, but in either case, it's too late. That's why there's dye
penetrant test and the like. Better yet is design. Europa seems to
have more beef in these parts relative to its light control forces
than some other kits and even production A/C?
Dissimilar metal corrosion will occur. I dipped the steel rivets in
the chromate prior to popping.
Regards,
Fred F, A063
> Question to the group.
>
> I am about to install the control system in the cockpit module and
> noticed a builder's web site discussing painting the control parts.
> Is this needed? I was considering zinc chromate for corrosion
> protection, but I would think a thicker coating of paint might make
> it more difficult to inspect for cracks down the road.
>
> Any opinions out there?
>
> Dave Anderson
> Gardnerville, NV
> A227
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