IMHO, this issue is caused by your environment. As other have rightly pointed out, what you have is simply aluminum oxidation. This is usually brought on by exposure to strong alkaline substances. This could come from living close to salt water or having a salt water fish tank in the same room, in which case the air's natural humidity level will convey the salt into and around your garage. Or, it could come from common fertilizer, salt, or other alkaline substance stored in the same area. Get rid of these high pH number bases, and the issue will most likely disappear.
► Adding an air conditioner will lower the humidity level and stop this. The water in the air is the transport medium, and with no humidity control and NJ's temperature swings, you're getting microscopic amounts of dew on your equipment in a highly repetitive fashion.
► If you don't want to add an AC unit, then another thing to consider is to add a one-time protective chemical coating to these pieces. The easiest process is a gold chromate conversion, which also go under the industry name Iridite or Alodine. You'll most definitely want the "gold" as that's a higher level of protection than "clear", which is merely the gold with most of the actual protection leached back off. These are very low-cost dip processes (as opposed to an electrically applied plating process). Do a search and you'll probably see several sources for Gold Alodine which you can apply yourself in 15 minutes using plastic buckets in a multi-stage dip process.
► The only other method is to seal out the air and humidity with annual applications of a heavy spray wax. Hornady and Dillon spray-on case lube would do an admirable job, but leave a waxy feeling film. A one-piece experiment would tell you if you could live with this solution.
Note here that paint is not generally suggested because these organic coatings won't typically adhere to the material surface due to aluminum's very rapid oxidation process. However, local powder coaters may have processes that account for this.
Best of luck.