[R-390] Painting Notes and Parts

[Barry Hauser]

Hi Boomer & List

I think that was me on the stripper -- no not THAT stripper.

The stuff I use is in an oversized can and says aircraft something or other
on it.  It's a caustic (non-flammable) type.  It worked, but not completely.

The panels were primed with one thing, finish coated with another, then
refinished once or twice more.  So you'll find a mix of things on them.
There are two basic kinds of stripper -- nonflammable (caustic) and the
flammable solvent gel types (napalm?)  The second type may work on some
finishes that the caustic ones fail on.  I used a combination of the
aircraft spray and denatured alcohol -- but not at the same time so as to
avoid generating nerve gas or explosions or the-end-of-life-as-we-know-it,
etc.

There was some stuff -- yellow primer -- that neither worked on and called
for elbow grease.  Best to start with a Scotch-Brite pad or similar abrasive
pad rather than sandpaper wet or otherwise.  It doesn't load up badly and is
easy to rejuvenate as you go along.  Never use steel wool as the filaments
dig into the pits in the aluminum and keep showing up in the new paint no
matter what you do.

As for cleaning out the lettering -- try one then the other with a detailing
brush -- I prefer the nylon one -- the brass scratches things.  I don't
remember if the stripper works or the alcohol on the lettering, which I
suspect is most often laquer, but who knows.  On stubborn spots, one of
Man's original tools is in order -- a pointed stick, also good for
diagnostic work in locating microphonic tubes and bad solder joints.
(Actually, can't credit "Man", as apes are known to use pointed sticks for
digging out  insects and other treats from holes in trees.  Not recommended,
for while rich in protein, also high in cholesterol.)

Finish off with wetsanding using a block behind it to even out the grain --
and sharpen up the edges of the stampings.  I suggest always
sanding/scotchbriting in one direction -- horizontal.  If there are no
gouges to fill, the panel looks so nice at this stage, I've been tempted to
finish with clearcoat and fill the lettering with black or nothing.  (That
snazzy brushed aluminum look!  One of these days, maybe even in this
lifetime.)

Before repainting, you should use a prep solution, such as Alum-Prep (they
say) but I couldn't find that nearby, so used a I used self-etching primer.
Gotta put it on very sparingly or you'll fill up the "engravings" too much.
(Then it becomes pointed stick time again.)

Spread out plenty of newspaper or a tarp you won't mind getting rid of.
It's a messy business, but somebody has to do it.

Barry

----- Original Message -----
From: "Todd Bigelow - PS" <tbigelow@pop.state.vt.us>
To: "David P. Goncalves" <dpg@coe.neu.edu>
Cc: <r-390@mailman.qth.net>
Sent: Thursday, May 08, 2003 11:33 AM
Subject: Re: [R-390] Painting Notes and Parts


> David P. Goncalves wrote:
>
> >1. Jeez, that paint that they used on the R-390 is tough to remove. I let
> >the knobs soak for a WEEK in Zip-Strip, and I still had to sand them. I
> >spread the stripper on the panel with a plastic scraper (which then
melted
> >into yellow goo) and still has to scrub it for an hour - and that was
just
> >the gray bits! The white lettering refuses to go!
> >
> Someone mentioned an aircraft-grade stripper that works quite well.
> Anyone remember what it was? I almost think it was Barry #1. It's
> amazing how scratched and hacked up these panels could get, considering
> how tough the paint is to remove intentionally.
>