Non-destructively, that isI already thought of fuming sulfuric acid and 12M hydrochloric acidI don't think aluminum would like those treatments though.Thanks in advance!
All good adviceEven with new windows you may still have some leakage thereIf they are not properly installed and insulated around, they are no better than the oldIN the attic you need to make sure there is still air circulationWhen we moved into our home someone had blown in insulation in the attic, but covered and plugged all the ventsThat was an uncomfortable summerSOme cheap ideasCaulk any cracks around your foundationEvery place that 2 different maerials meet should be cau;ed or filledRun a bead of caulk around the exterior of the windows and doors, including the bottomsIf you have large spaces to fill get some expanding foamAsk your power/oil company about an energy auditThey are usually free and you get free suggestions from a professional, info about incentives on energy projects, and free goodies like lightbulbs and low flow heads.
Don't do itExposed foam is a fire hazard, and as an insulation, it's far more expensiveI bet drywall is more sound-deadening, too, just because it's more denseI'm not sure I can see any potential positives to this proposed project, and I'm sure it violates safety standards and building codes.
Ah - but what about conc nitric! Al is passive in conc nitric thought to be due to formation of an oxide filmAnd since hard water deposits are CaCO3 and MgCO3 they should readily dissolveBut try on a small disposable piece firstI have used conc nitric acid in this way to clean steel bombsOtherwise try vinegar applied with a paper towel (rubber gloves) until the Al is shinyVinegar is used to rid coffee makers of scaleGood luck!
