I left my thermostat too long and had to work to get it out. The housing and cover are encrusted with, I think, mostly salt corrosion.
Any suggestions for cleaning away the corrosion without damaging the aluminium?
Muriatic acid will clean it up in a jiffy, but it is scary stuff. I've had a gallon of it around for more than a decade. Just takes a little bit and maybe a minute. Mine came out so good when I replaced it that I kept it as a spare. I suppose that cleaning vinegar (more acidic than cooking vinegar) would work in a soak for a couple of days.
Sodium bisulfate can be used to make an acid much stronger than vinegar, but not scary to handle (like muriatic acid). Sodium bisulfate is easily purchased as a hot tub or pool chemical for lowering pH.
To make an effective 10% sodium bisulfate acid soaking solution; add 4 tbsp sodium bisulfate to 4 cups water
