I am attempting to restore the finish on some 40 year old aluminum window frames. I began by using barkeeper's friend (w oxalic acid) but that only addressed a part of the problem (the oxidation) leaving it haze covered. Then I tried AutoSol which remove oxidation and left a shine but is really pricey. I am now trying Mother's Mag & Aluminum polish which works as good (so far) as the AutoSol at about a sixth of the cost (I really haven't done the math, only guessing). I believe that both of these later two products have distillates in them.
Here is my problem, part of the windows have a pasty, yellowed substance that is on the outer part of each frame. I cannot figure out what it is. I can scrape it loose but it is really stubborn. I put a heat gun on it and it softened up quite a bit. I am thinking it is something held on by an adhesive, but the Mother's or AutoSol should cause it to loosen but they don't. Heck it vaguely looks waxy. Does anyone have any ideas? I am fearful of getting too rough with it because that would scratch the surface of the aluminum.
The Following User Says Thank You to drdavis62 For This Useful Post:
you will notice the fine job done by the Mother's/AutoSol polish and the difference of the side frame pieces (pic #1 & #2 show area where I used heat gun). I should add that I am reluctant to use the heat gun too much because I am afraid that I will loosen the adhesives on the window.