Hello Matt---
I completely restored my '46 Coupe over the last couple of years,
so
I'll give you a few tips as I have learned them from a crack A & P.
I would remove as much interior as possible, including the seat
back
and seat pan and vacuum the interior rather than introducing excessive
moisture. It is amazing how far a person can crawl back toward the tail
if he/she has to. Get as much dirt, etc as you possibly can out, as it
not only is extra weight to carry around, it collects moisture.
Moisture is the main catalist of corrosion. Take a strong light inside
with you so you can inspect the surfaces closely. Look for white powder
(aluminum oxide surface corrosion) and for black speckling (this is also
aluminum oxide surface corrosion in its earlier form). If you find any
you should use a stainless steel brush dipped in acid etch (follow the
directions on the bottle) to remove all traces of corrosion. You can
buy the acid etch at places like Aircraft Spruce, etc. Then treat the
aluminum with Alodine or equivilant conversion coating (also available
at Aircraft Spruce, etc.) as instructed. Check the main spar caps for
intergrannular corrosion. This is corrosion that starts from within the
extruded piece, not from the outside, the way surface corrosion starts.
Intergrannular corrosion many times cannot be detected until it starts
to exfoliate. Exfoliation can sometimes be detected by sliding your
fingers along the cleaned surfaces. It can feel like small pimples in
it's earliest stages, all the way to splinters that look like rotton
wood in it's extreme stages. You should do this on the center section
main spar, front and back, top and bottom machined surfaces, and also on
each main wing spar from the wing fittings out to the splice point to
the tip spars.
If all is o.k. you should protect the surfaces from surface
corrosion
by spraying with zinc chromate or, better yet, epoxy chromate paint. Be
sure all surfaces to be painted are very clean before starting to
paint. I recommend using Paint Cleaning Solvent from Aircraft Spruce,
following the instructions carefully. Mask off everything that is not
to be painted.
Good luck,
Syd Cohen
NC94196
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