Pitted aluminum frames and trim

The frames/trim around the house windows are aluminum and pitted. I want to refinish them to look nice. I was thinking of sanding them smooth, filling the pits and painting them. Rustoleum has a nice brushed aluminum paint that I think would look good. What would I fill the pitted areas with?
Thanks
Jim

I have tried many things over the years to try to fill pitted outboard housings with very limited success. The problem, as I see it, is that unless you get every bit of the aluminum oxide out of the pits, you will not get anything to stick in the pits and they will continue to fester and bubble up whatever finish you apply.
One thing I have never asked about is Por-15 on aluminum, it performs wonders on rusted steel but aluminum, I don't know. I would call and ask them

jclays said:

The frames/trim around the house windows are aluminum and pitted. I want to refinish them to look nice. I was thinking of sanding them smooth, filling the pits and painting them. Rustoleum has a nice brushed aluminum paint that I think would look good. What would I fill the pitted areas with?
Thanks
Jim

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Did ours about 4 years ago. Scraped and sanded them as smooth as I could. Cleaned them thoroughly with what the paint manufacturer recommended (can't remember what). Then used an aluminum compatible primer/tie coat paint (2 coats) followed by 3 top coats of enamel. So far so good. Didn't fill the pits with anything. Five overall coats of paint pretty well filled them though.

Pitted aluminum filler

I have used MARINE TEX with great success when filling pits in aluminum.

Any and all paint is first stripped from the surface, hand sand to a reasonable level. Then clean the surface with a rag dipped in an evaporative cleaner that leaves no oily residue.

Apply the Marine Tex using an appropriate sized plastic spatula and let it dry, it won't take long.

Again, sand smooth and clean the surface. Apply primer and paint.

It will be a little more complicated if the aluminum is beyond simple pitting or you have an electrolysis problem on the vessel.

Frank

I have nursed small outboard aluminum props for many years with marine tex and not a lot of prep work...

But to do it right...there are primer systems to use on aluminum that I think contain an acid wash to get rid of the oxide. Some basic internet searches should reveal them easily.

I used to own a boat where somebody had spent a bit of money having the window frames painted with a two part poly. It was gorgeous. About two years later I watched as it all started lifting, bubbling and turned into a leper.

The windows had not been prepped right for aluminum.

Do a search for alodine and alumaprep. If they are not etched properly, the prognosis long term is not good. Porous aluminum from pitting is the hardest to handle. I would not invest a lot of money in old frames that have pitted. For best results, you want to immerse the frames, that can be a bit of a chore.