One way I like to deal with that type of situation is to clean as much chalk off as you can then use a binding agent to lock the rest down.

This product has worked well for me;

http://www.seal-krete.com/original-masonry-waterproofing-primer.html

It's primarily a masonry sealer/primer but is also made for use on chalky aluminum. It will lock down any chalk residue and act as a primer for an acrylic top coat.

If you are able to clean %100 of the chalky residue off you can just paint it with a good acrylic. The Seal Krete comes in handy when removing all the chalk isn't practical or possible.

 

ok. but how to clean them ? water, soapy water, nuclear waist ? i know i would need a stiff brush to work it.

 

Yeah, just water and some mild detergent or house wash. Scrubbing with a brush definitely helps.

Since its windows instead of siding, I might use an exterior glass cleaner like this;

http://m.homedepot.com/p/Windex-32-oz-Outdoor-Glass-Cleaner-040132/202872010

That way you clean the glass at the same time. Detergents and house washes can leave residue on the glass that has to be removed later. Water and elbow grease are the main things you need to remove chalk anyway.

 

Water and a scotch brite pad work wonders on chalky aluminum storm windows. Rinse well with a garden hose and you're done.

 

excellent, guys :thumbsup:

i have a laundry room i need to finish, kitchen/dining room flooring to plan.
but when i get a break, i will get on this. as these windows/trim are the 2nd to last thing that remain white on my house = gotta do some'n bout dat.
front screen door is the last thing. i am thinking some kind of red, but idk yet.