Powder Coating Vs. Spray Painting on Cast Aluminum

by J. Lang Wood
Cast-aluminum outdoor furniture sometimes needs refinishing.

Cast-aluminum outdoor furniture sometimes needs refinishing.

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Many products found around the home are made of cast aluminum. Cast aluminum is an inexpensive material that can be formed into many attractive shapes and designs. Toys, fence parts, fountains and outdoor furniture are just a few household objects often made of cast aluminum. If you are engaged in household maintenance tasks, consider the advantages of powder coating vs. spray painting for your cast aluminum repairs.

Advantages of Powder Coating Cast Aluminum

Powder coating is a process in which a powdered paint is electrostatically charged and sprayed onto a metal surface. It is then put into an industrial oven to allow the powder particles to melt, forming a durable, continuous film, according to Finishing. The resulting coating is tough and abrasion resistant. Powder coating can also be applied in a wide variety of colors for every décor and a large range of thicknesses for any purpose. Powder coating resists fading, chipping and oxidizing, a whitish coating that aluminum tends to develop over time.

Disadvantages of Powder Coating Cast Aluminum

Powder coating must be done with special equipment by trained technicians. It is generally more expensive than ordinary spray paint. Because the work must be done in an industrial shop environment, you may have to wait some time for the item to be completed, as particular paint colors are often done at the same time. Powder coatings on cast aluminum can fail when gases trapped within the porous casting escape, piercing through the coating. This can causing flaking and deterioration of the finish.

Advantages of Spray Painting Cast Aluminum

Spray painting is another method of finishing cast aluminum pieces. Paint in many different colors is readily available at local home-improvement centers. Spray paint is relatively inexpensive and can be done whenever the homeowner has the time. Touch-up painting can be done whenever it is needed.

Disadvantages of Spray Painting Cast Aluminum

Old finishes must be removed before spray painting to get good adherence. The surface should be roughed up with 220 sandpaper before applying the spray paint to increase adherence, according to "This Old House" magazine. Special etching primers for aluminum can also help the paint adhere to the surface. Spray paint can chip off areas that see continuous contact with other surfaces. Spray painting aluminum is messy and requires an open area in which to work. Spray paints are smelly and can cause lung irritation. You must ventilate the work area properly and wear a respiratory mask to protect lungs. Spray paint can drift into other areas, causing undesirable coloring on nearby surfaces. Spray paint cans must be disposed of according to local toxic-hazard regulations.

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