Aluminum window frames - chalky white residue

Been searching for about an hour, here and other places, but havent found much info.

Can someone tell me what is going on with these frames, and if it is something that should be fixed, be ignored, or be avoided? As you can see, a light swipe leaves your finger looking like it was dipped in white paint.

I dont know much about painting processes and or aluminum construction materials. I mentioned something about it looking like paint, and someone nearby said they werent painted… so ‘assuming’ he was correct, are these powdercoated or something? Is this an oxidation issue?

It’s a regular pita when cleaning windows. Our options are to dry the glass with a squeegee and wipe the frames dry with a rag… or use water fed pole and rinse, rinse, rinse, rinse, rinse… you get the idea.

If you are pressure washing without going back if the windows afterwards I suggest your two best options are;

  • rinse the living crap out of the windows! Eventually you will have rinsed off the loose and dissolvable oxidation and won’t get white streaks

  • during pressure washing scrub the window frames with a brush. This will quickly remove the loose oxidation and there will be less available to disolve into the water sit ing on the frames. You’ll still get drips on the glass like usual… they just won’t be milky white.

Adding acid cleaners to your mix not worth the hassle. Theyll still need scrubbing with a brush.

If you have lots of these windows in your area maybe add another 30mins to each quote for rinsing. Or invest in WFP and upsell exterior window cleaning. Or call it a “spot free rinse” and make it a compulsory service for these jobs.

Hope that helps.


Great help Buzz, thanks for taking the time to explain it.

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You’re lucky mate! You got my one useful contribution this week :wink:


Yes, it is oxidation. If you dont have a pure water system, buying distilled water at a grocery store and pump spraying will achieve the same result.

Of course, as a window cleaner first, I am referring to the glass. You may be more concerned with the siding?

If it’s badly oxidised you’ll Be using a lot of Pure Water. That could take all day with a pump sprayer!

I’ll set my wfp to 5 litres per minute if I’m trying to scrub and rinse off oxidation… how bigs ur pump sprayer :hushed:

Yeah i was thinking for just a little detailing.