What Is Lacquered Aluminum?

Aluminum is a useful material for vehicles, furniture, building and packaging. It is conductive metal that does not corrode easily and is very lightweight. The metal evaporates at high heat and condenses onto a cool surface, which is how many mirrors are made when the aluminum is condensed onto glass. Aluminum can take many types of coatings from paint to plastic to lacquer. The lacquered aluminum is most commonly used in food packaging.

An alloy that can be formed into may shapes and thicknesses, aluminum can conduct electricity 60 percent as well as copper. This fact and the ability to form it into thin wires makes it a good substitute for copper wire in high voltage electrical applications. Much aluminum is pressed into sheets less than a thousandth of an inch thick and used as foil. It is also preformed for car and machine parts and is an important material for aeronautics because of its light weight.

Aluminum can be coated with a variety of substances to increase its durability and attractiveness, to prevent corrosion and oxidation, or to make a product stronger. Lacquered aluminum foil is lightly coated with a clear lacquer to prevent food contact with the aluminum. Other lacquered aluminum is usually colored. The coating is low viscosity and very thin. Lacquer is a surface application that enhances the vapor barrier, increases the strength and tear resistance of the aluminum, and increases the gloss and adherence of other coatings. Lacquered foil is common in such things as yogurt tops and candy wrappers.

Applying a lacquer to aluminum metal is not much different than any painting process. The foil, sheets or pieces must be stretched over a frame to minimize wrinkles and ensure a smooth surface. In factory applications the lacquer is rolled or sprayed on by a machine. The foil doesn't absorb the coating, which must then be dried to cure it onto the metal. Radiant or infrared heat are the most common heat curing processes. The material then is allowed to cool gradually to further cure the lacquer.

Several products on the market will coat aluminum easily. Any paint or lacquer that works on metal is appropriate for covering an aluminum surface. A mixture of 100 parts of gum lac and 300 parts of ammonia are heated for an hour and then cooled. This solution makes a basic lacquer, which requires heating at 572 degrees Fahrenheit after application. For thicker coats, the process is repeated several times. Lacquered aluminum is mostly corrosive proof, but salt water is damaging to the surface.