Antique pressed aluminum loses its shine and darkens with age. A tray that hasn't been used in years may even appear black. However, there's no reason to get rid of tarnished or dirty aluminum. Uniquely designed antique pressed trays are perfect for serving desserts or appetizers to guests and can be restored to look like new inexpensively with homemade cleaning products. Most aluminum cleaners are acidic so be sure to protect your skin when restoring your trays.
Put on rubber gloves. Fill a large pot with about 1 gallon of water, 8 tablespoons of cream of tartar, and 2 cups of vinegar or lemon juice. Bring the mixture to a boil.
Plug your sink and pour the mixture into the sink. Soak your aluminum trays in this aluminum cleaner for about 10 minutes.
Drain your sink and fill it with hot water. Add a mild dish soap.
Soak your aluminum trays in hot soapy water for several minutes. Use the scrubbing side of a sponge to lightly brush and polish the trays.
Dry your trays softly with a dish towel. Apply a metal polish to shine them up.