Probably best is to alodine the aluminum. Apply the chemical and wash=20
with water, dry and paint. The acid etch primer or a zinc chromate=20
primer followed with your top coat. I really like the polyurethane auto=20
paints. Ditzler Concept series has performed super. Understand they are=20
moving toward water based coatings, going to check that out with next=20
major project, but for now all set with hardeners, reducers, etc. To buy=20
alodine, check out Aircraft Spruce, Wicks Aircraft, or your local auto=20
body refinish supplier.

On 6/14/2011 5:08 AM, Michael Watterson wrote:
> On 14/06/2011 09:57, jimf@webstudios.co.uk wrote:
>   =20
>> 	I used "Acid etch primer" as this bites into the aluminium to stop
>> the paint from flaking afterwards.
>>
>>     =20
> I discovered long ago you can't paint or spray "fresh" Aluminium. It
> needs exposed, etched&  oxidised or anodised..
>
> Freshly made aerials washed with saltwater and left on the lawn for a
> week and then polyurethane varnished don't corrode. If painted fresh
> they flake badly and if unpainted or not anodized they corrode badly.
>
> Good quality bare anodized seems best.
>
>   =20
--=20
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