Hi,
I'm expecting my empennage for the RV8A to be delivered soon. I have looked over the subject over and over on this forum (and the internet) but failed to find the way to go. Can someone recomend me an environmental friendly (as possible) anti corrosion treatment for the internal parts of the plane?
"Friendly" as in: don't kill the guy spraying/putting it on (me
).
Please included some suggestions about using the same stuff on the outside of the skinns as well. As a base for the color paint to go on.
When finished, the plane will be hangared close to the North See, so some protection against the salt is needed in my opinion.
I'm planning on treating the whole of the internal parts of the emppenage (not only the contact parts).
Thank you,
Duncan
I have used lots of time investigating this (maybe way too much
). The thing is - you
need a primer with anti-corrosive agents. Automotive primers usually work well on steel, but do not have the right ingredients to give aluminium proper protection. In the aero-industry, at least in Europe, one key element is
epoxy primer with strontium chromate.
Just up untill some few years ago, Zinch Chromate in rattle cans was readably available, but is now illegal and very hard to get. I got hold of one can that I use as touch-up.
Zinc Oxid and phosphates, the ingredients in "real" non-chromate wash/etch primers, are excellent on steel, and will also prevent filliform corrosion in aluminum, but is a coating that need more coats on top. On internal parts of alclad I wonder if it is just as good leaving the polished alclad alone instead of using a wash primer that is specifically designed as an undercoat for topcoats. Filliform corrosion is probably one of the most common corrosion on aircrafts in salt/humid environments, but is something that occurs
under the topcoat, so when you have no topcoad, you have no chance of filliform corrosion either.
The standard for corrosion protection is:
* Cleaning the aluminium (derinoxalu for instance)
* Wash primer, with zinc oxid and phosphates
OR
* Alodine
Then
* Strontium chromate epoxy primer
* Top coat(s) of polyurethane/epoxy
On internal parts, strontium chromate epoxy is enough.
The Strontium Chromate epoxy primer protects the aluminium electrochemically against corrosion, and is tough and hard so it also protect against physical damage and chemicals (oil, fuel etc) and is waterproof (a wash primer usually isn't).
I use primer/paint from
Monopol in France. Except from a little local "primer war" with the importer here in Norway, I am very satisfied. They don't sell this stuff in local house and garden kind of shops, but I guess you, living in Holland, can just drive to them an get the stuff? You can also contact the sales agent Gerard Florsch (
[email protected]).
The strontium chromate epoxy will give you the best possible protection on internal parts. It is probably the only thing that will give you full protection. Given the choice though, I would use zinc chromate rattle cans on all internal parts, because it is much easier to use, even though i is not nearly as good as the Strontium chromate epoxy.