Aluminum frames are sensitive to many cleaning agents in the marine environment. If you don't take precaution to clean and rinse the window frames after each cleaning of the area around them, you may end up where I ended up: ugly streaks on the frames. I have tried a lot of things, including sanding, polishing the metal. Still streaks. There must be many boats that have aluminum frames. What have people done to repair this? I once read in PRACTICAL SAILOR that at some point the frames have do be 'removed and professionally worked' on. I have a similar question as Mark: I wonder if there is anybody out there that has found a solution for cleaning these frames -- without having to remove them?