Duane,
I went through just these issues myself recently when I started my wings
- until now I, like you, had just Alodined/Alumadyned my parts and then
embedded them in epoxy parts.
My plane will have to cope with UK weather, with some significant
coastal exposure up in Cumbria (windy, wet, salty, sandy).
I reviewed everything I could find on the Forum archive, checked with
the Factory, asked my inspector, and checked with the builders I know.
I settled on:
1) Alodine/Alumadyne everything (with appropriate cleaning using
PolyFiber's alkaline cleaner and ScotchBrite pads - from Aircraft
Coverings Ltd.)
2) Make all joints between dissimilar metals with Duralac (Light Aero
Spares stock this)
3) Paint the completed aluminium parts with Zinc Chromate (LAS again)
4) Paint the parts that will be visible from outside (bellcranks, ends
of the pushrods) with white gloss (LAS again, for convenience) - just
for prettiness
I haven't done any steel parts yet, but I do have spray and brush-on
Zinc Oxide (spray from local supplier, brush-on from Halfords).
I ruled out powder coating and anodising for the following reasons:
1) I wanted to work with parts as the jobs came up - not in one big lot,
which is less convenient for outsourcing the work
2) I recognised that considerable tweaking of parts is necessary
(putting the bold clearance on the quick-release bellcranks, ovalling
the aileron bellcrank mounting holes to fit the spar bolts, drilling out
the undersize laser-cut holes) and that treatment _after_ cutting these
parts is required
3) I have a very restricted workshop (8' x 16') and needed a process
that was not space-hungry (e.g. an oven for the powder coating)
I hope this helps!
Regards,
Jeremy
Jeremy Davey
Europa XS Monowheel 537M G-EZZA
-----Original Message-----
From: forum-owner@europaclub.org.uk
Subject: Aluminum Prep
I'm just getting into the wings on my XS Trigear. All of the aluminum
parts
that I have used so far were being bonded into the epoxy. So I used
DX503
Metal Cleaner followed by DX533 Alodine. But now I'm getting into parts
that
are gonna be inside the wings but not inside epoxy. Bellcranks and arms
and
stuff. Is this cleaner/alodine prep sufficient or should everything now
also
be powder coated or zinc cromated? I guess the same could be asked for
all
the metal stuff inside the fuselage. If all this stuff were to be taken
some
place to have them do the coating all at once, how do you know what
parts are
what part number when you get them back?
Not wanting to reinvent the wheel.
Thanks in advance.
Mike
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