I come across these stains very often and I have to tell the customer before hand that they will not come off with my standard house wash mix. I would like to be able to clean these off, I’m sure you guys have came across these before. What is the most effective way of cleaning them?
Have you tried light agitation with a brush? Just remember that if there is oxidation in that area you may end having to brush a whole section to make it not stand out.
Acid. One restore.
Window/screen frame staining most likely. OneRestore is my go to on that stuff, full strength, dwell couple minutes and rinse.
I have not tried that. Figured it might not make a difference…
If OneRestoreisn’t readily available you might want to try aluminum wheel brightener with hydrofluoric acid. This stuff works so good on rust stains that I don’t even waste my time with oxalic acid any more.