Alodyning skins and large sheets

I'm trying to figure out the "priming problem."

I took the SportAir course on RV assembly and it is well worth the time &
money. It's intended to get us beginners ready to build an empenage.
Priming was briefly outlined, as follows......
1- pull the plastic & clean the metal w/ MEK
2- use Alumiprep #32
3- use Alodine #1201
4- use AKZO fast drying interior epoxy primer (that's what it's called in
Aircraft Spruce catalog at $111 for the 2 gal kit and $50 for the thinner)
Oh, and don't breath any of this stuff or get it on your skin..... or you
will die a horrible death.

Does "interior epoxy primer" mean you shouldn't use it on the exterior?.....
seems like a fine distinction when dunking a part in a tub.

Then reading "Aircraft Painting & Finishing" (Jeppesen) one learns that 2
part "epoxy primer is the most popular for use under polyurethane finishes
and where max. corrosion protection is required."
Also,
"Zinc chromate is still a good primer as far as corrosion resistance is
concerned, but it is inferior to the others with regard to adhesion.........
it can be effectively sprayed over a surface which as been properly treated
with a conversion coating such as Alodine..... the Alodine provides for the
adhesion."

Both sources say.... "well, there's rattle cans and then there's the best
way."

I emailed Van's and asked if the QB kit comes primed and if so, with what
.......... so far, no response.

Then I called SportAir inquiring about their course in painting. It's only
offered in Griffin, GA, and not this year.

So, it seems the choice is A) the inconvenient 2 part epoxy system or B)
second rate rattle cans.

I figure that whatever they do for the QB program should be good enough for
the empenage...... right?????

Also, does one have to drill, cleco, de-burr, etc, etc. and then prime, and
then re-fit all the parts before finally driving rivets?????

See the problem??? .... the priming part of the equation sound like a real
fun-killer.






"Ed Wischmeyer" wrote in message
...
Anybody have any favorite techniques for doing big pieces? I've not been
able to find any alodyne tanks locally, and I've only got a gallon each
of aluminum cleaner (phosphoric acid) and alodyne. The option is to use
a self-etching primer on the inside.

Ed Wischmeyer
RV-10