Bob Harrison wrote:
>
> Hi! All.
> ...
> I found, much to my disappointment, a small amount of corrosion on the flap
> brackets under the paint, evident by the paint showing signs of blisters.
> When preparing the brackets I etched them with phosphoric acid diluted 5:1
> washed off well
> dried and then coated with Etch Primer (D360-1 with Toluene and Xylene)
> Mixed 1:1 with Etch catalyst (D360-1) Then two coats of Plasti-kote metal
> primer grey undercoat and at least two coats of white Plasti-kote gloss.
> The oxide blistering the paint was white but close to the good metal it was
> black.
> ....
Maybe the black is something in the paint. But I've found that
nothing in a consumer spray adheres to anything but intended
surfaces. Even if the surface is abraded before etch, etc.
In 1985, I repainted my AA-5, using PolyFiber's EP-420 2-part Epoxy
primer. Mostly has been outside, and even in tough areas like
underneath A/C, or on brackets where you got corners that start the
peeling process, no problems to date.
I've used it on all the Europa parts. Horrid odor, measure/mix, wear
respirator, discard excess, thoroughly clean gun each time, for just a
few parts. Wouldn't have suffered all that if I wasn't sure. It
adheres tenaciously, if prepped right, and word is Boeing uses a
similar product in some places.
Conversely, when I removed a Loran antenna from underneath, and did
all you did and using consumer-type paints, the patched area failed in
two years.
Best,
Fred F.
|