I'm sorry if this has already been asked but I could not find it on a search here though I also could not determine how to search for the presence of two words ('ammonia' and 'aluminum')
I've read mixed results about whether using household ammonia on aluminum is damaging or not. In my case I want to use it to clean baking trays by putting some (~ 1 tablespoon to 1/4 cup) ammonia on the pan and cover it with a plastic bag and set it aside for hours or a day or so to allow it to soften the baked on grime. I also want to and am using it for a variety of other household and tinkering projects. I read on one site that it is a very bad idea to use ammonia on an aluminum bike frame because it will severally weaken it.
Does household ammonia damage aluminum?