Poly seems to have been used more or less exclusively in GA during original manufacture, but as far as present-day usage goes, it seems to be going out of fashion and everybody is going acrylic. The "2K" 2-pack stuff is very popular and works very well.
I am told by one supplier (Jawel) that acrylic is as good on avgas resistance as poly. But anyway I can use Aerokote lacquer on top afterwards (on small components).
What do the good GA aero spray shops use?
I am not spraying a whole plane
Just little bits here and there.
Another thing is which primer to use. It's patently obvious that the commonly available aerosol zinc chromate primer (from aviation suppliers) is rubbish. It barely sticks to anything, doesn't dry properly, and while it does have the desirable electrolytic protection property which is why it has been used since ~WW2, the rest of the world seems to have gone to 2-pack primers. Or epoxy primers which are obviously 2-pack. They also use etch primer (
Acid #8) especially on aluminium or anything galvanised.
Socata used Mapaero poly coatings, which are nothing special apart from being French and sometimes very expensive. Even on the $3M TBM700 there have been cases of large areas just peeling straight off (wings having to be re-sprayed) presumably because the paint was done in too-high ambient or whatever. The problem with the Mapaero stuff is that it is French
and is a bastard to purchase from a "difficult" company. Also the shipping is "hazmat" and I have just been quoted 170 euros for shipping on a little 1 litre bottle. The bottle itself is just 30 euros. One Mapaero job I know of took 6 months just to buy the paint... I could almost fly to Tarbes in France and back for 170 euros, but Socata don't sell direct (unless you live in Australia
).
Another Q which somebody may help on is metallic lacquer. In the auto trade this seems to be rather 1970s and not common. For example Jawel won't even discuss it. I have some of the correct
Mapaero "pearlescent" metallic lacquer but (as I wrote earlier) I cannot at all easily buy the stupid hardener for it. It is easy to get lacquer (e.g. 2-pack
Aerokote) but can one put metal flakes into it? I am not talking about the massive Starsky & Hutch era flakes
Just a very fine metal powder.