Use epoxy on bare Aluminum ?

J

JR4 Motorsports

Or other primer?

I picked up a old piece of ham radio equipment recently, and the outer case is aluminum. Well it was painted green, and smelled fiercely of cigarette smoke, so in the dishwasher the case went, and when it came out, a good deal of the paint was taken off, actually it looked like the paint was so old and dry that the hot water peeled the paint off, and after drying for a few hours 80% had flaked off ! I used Tal Strip to get the rest off, and now I have a bare case needing some primer. What do I do to prevent this peeling in the future? I was thinking of epoxy priming, then a top coat of some color, to be decided. Any special prep for the aluminum?

Thanks
 
Yes epoxy is fine on aluminum. In your aplication 2K would work also.
Prep is same as steel, roughed up with sandpaper or grit blast and clean with WGR.
 
Can't blast, but will a rough scotch brite work? The cabinet is also punched with hundreds of small holes for ventilation, what would be the best was to make sure the paint didn't peel off the sides of the holes. The panels are about 3/32" thick, the diameter of the holes are about the same.
 
Can you post a photo?
Epoxy may be better if you want to get into the holes, it stays wet longer than 2K is less likely to produce dry fuzz in the holes.
Making sure the sides of the holes get sprayed will require a different approach than spraying straight on for a plain straight surface.
 
I will post some tonight.

ok, here are some

It's a clam shell case, the top 1/3 hinges open from the top IMAG0189.jpg

IMAG0188.jpg

IMAG0190.jpg
 
The part seems to be in good shape other than the dead paint which is just about gone. Get rid of the old coating completely with the stripper or by sanding. Then go over all to dull the surface and give the primer a tooth to grab. I think I would go over it with 180 grit sandpaper but you could use the scotch-brite, just more work and less tooth. Then give it a good wash with Dawn soap, rinse and dry thoroughly. I use doctor gloves when handling preped metal to prevent puting oil from my hands on the surface.
One of the benefits of epoxy is it's adhesive quality to the substrate, it can be applyed very smooth with some reduction and can be top coated with good intercoat adhesion as long as you don't let it fully cure before top coat. You can also sand it to get rid of trash or if you don't like the surface.
If you spray both sides on an angle from opposite directions you should get material in the holes.
 
I was thinking of useing a brush, on the inside, and allow the primer to run through the holes. then sand the outside smooth and spray the outside. But I can't do that with a top coat, so I guess I am going to have to figure out how to spray the holes from different angles like you suggested. Now to work on picking out a final color.....
 
JR, my vote is for epoxy. And if you decide to paint it black, white or gray it could be done in one step!
 
epoxy i think is the way to go. anytime i have tried 2k on sanded aluminum it peels off in sheets within a couple few weeks.
 
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