REFLECTOR: Auto Marine or Airplane paints

[Terry Miles]

Geez,

When I started on this project in earnest about a year ago now, I wasted
a lot of time reading tool catalogs.  If I was smart, I would have
signed up for a speed reading course instead.  What follows is a
rambling rant with this question to the Reflector...why did you guys
chose for or against auto paint over marine paint over airplane paint?
Sherman Williams, PPG, Akzo-Nobel they all have car, boat, and airplane
products.  

For tonight at least my inclination is a nothing exotic, mid priced,
run-the-mill automotive paint unless someone out there would caution
against it.  Reasons include cost and worries about the product
experience of the painter and the tools at his disposal. (I am using the
body shop next door to where I am building which will shoot anything I
want in a regular spray booth big enough to fit the fuselage section.).
I can use high VOC polyurethanes here in SC, and these products are said
to be more results friendly, so I could go with marine or airplane lines
if I saw the value to it.  

For the conversation, here's some terms I have learned recently.  "Top
coatings" are referred to in the auto world as base coat & clear coat
systems.  Sometimes these "top coatings" require a given type of
undercoating, sometimes 320 grit sandpaper is enuf to make any
undercoating compatible with a topcoat product. Obviously aftermarket
autobody repair products can't be fussy.  (Read the pdf's).
http://www.lesonalna.com/  Under the Akzo-Nobel auto line of products, I
used Utech for undercoating and anticipate using Lesonal products for
topcoatings.  I called the Lesonal product line and was told among other
things that (in general terms)  the higher up the price range in their
products (Sikens product line) the fancier the end result, but less
user-unfriendly regards application.  (OR) It could also mean that you
are looking at newer more environmentally friendly chemicals, which are
required in Europe as much as in the USA.  As a aside, clear coats do
have the UV properties at least in the Lesonal line.  The colored base
coating of their topcoat systems do not have the UV protection.
Airplane topcoats, JetGlo as example, can be applied without clear coats
so UV issues are different.     

Akzo-Nobel is a very big multi-national org, based in Holland somewhere.
Ronnie Brown used their marine Awlgrip on his bird.  I am looking at
Lesonal which is one of their auto paint lines.  Alumigrip is in their
airplane line, and it used extensively in GA certified stuff.
http://www.akzonobelaerospace.com/products/category_selection.aspx?id=Po
lyurethane%20Topcoats    
Further I have learned that nobody's auto/boat/airplane paint sales
departments are not crossed trained, so we all are left to our collected
wisdom. 

Anybody have any thoughts on auto vs marine vs airplane?

Terry


HISTORY
If I helps future generations, below is more detail on what we have done
to date.

At Hangar 18 we started w/ a "primer-surfacer" and did the sand out and
patch fill routine, until one day we said "enuf is enuf."  (Actually I
got to that point way before M. Collier did.)  Then we sprayed on a
final "primer-sealer" coat.  All this was done just in the shop w/ good
ventilation, but no spray booth.  These are two different products and
both are referred to by Akzo-Nobel as "under coatings."
http://www.akzonobelcarrefinishes.net/default.asp?sid=65395&pid=420
This was good stuff.  Not too costly.  Hangar 18 has painted about 5
airplanes with it and had good success.  Here are the details.

The first sanding of the exterior surfaces is w/ 40 to 80 grit.  Then we
rolled (not sprayed) on 2 coats of UTECH U2K1 Primer with stock
activator being A2K4.  Watch out, product labeling seemed to change.
Primer bought later just was labeled as 2K, but with a "product code" of
P2K1.  The web site had it as 2K100.   Rolling as opposed to spraying
this first coat forces the paint into all the little pin holes.  Then it
is guide coated, which is just a very light misting of diluted black
acrylic water/based artist paint.  This allows us to see undulations as
we sand.  We used long sanding boards now about 12 to 14 inches long.
The grit of the sandpaper gradually goes up to 180 at the end.  After
the roller coats are sanded out, we do it again.  This 2nd time just one
spray coat of the same stuff is sprayed on.  Guide coated again and
worked with 180 grit paper.  It helped that this first primer surfacer
had a slight coloring in it.so that the last "primer-sealer" coat (UTECH
E366 and the hardener is E375)which was white-white could be seen as a
dif color as it was sprayed on.  This helps the sprayer see what is
happening-at least for the first sealer coat.  Two coats of sealer were
applied.    
End.