How to Paint Diamond Plate Steel

This is an example of the diamond plate steel pattern.

Diamond plate steel comes from the factory with a protective coat of lightweight oil to protect it from rusting. This layer has to be removed before paint can adhere properly to the surface of the steel. Industrial painting companies have automated systems designed to clean these surfaces chemically before painting, but for the small do-it-yourself jobber, there are a few items that can be used to remove the oil. Once the oil is removed, the steel can be primed and painted.

Things You'll Need

• Rubber gloves
• Paint thinner
• 1-gallon metal can
• Paint rags
• Brass wire brush
• 2 spray bottles
• Simple Green cleaner
• Toilet scrub brush
• Vinegar
• Safety glasses
• Paint respirator
• Steel rust-resistant aerosol spray paint primer
• 180-grit sand paper or finer
• Tack cloth
• Steel aerosol spray finish paint

Instructions

1. Put on a pair of rubber gloves. Fill a 1-gallon metal can with 3 inches of paint thinner. Dip a rag into the paint thinner until it is saturated. Hold the rag a few inches over the diamond plate and wring out the paint thinner onto its surface. Brush the paint thinner around with a brass bristled brush. Wipe off all dirty paint thinner and lay the soiled rags out to dry. Continue this process until the protective layer of oil has been removed from the diamond plate steel.

2. Fill a spray bottle with Simple Green solution and spray the entire surface area of the plate. Scrub the surface with a toilet scrub brush. Wipe off the dirty solution and lay the rags out to dry.

3. Fill a bottle with vinegar and spray the surface of the diamond plate. Scrub the surface with the toilet brush. Wipe off the dirty solution and lay the rags out to dry. Rub the surface of the diamond plate with clean, dry rags until completely dry.

4. Put on a paint respirator and safety glasses. Paint the plate in a side-to-side motion with the aerosol can of rust-resistant primer. Continue priming the surface until coverage is definite. Wait until the primer is completely dry and then lightly sand it with 180-grit sandpaper. Tack off the primer paint dust with a tack cloth.

5. Spray paint over the primer with the finish coat. Use an aerosol paint specifically designed for steel applications. Maintain a consistent speed throughout the painting process. Maintain an even distance from the surface, following the spraying instructions on the label. The finish coat should be a consistent sheen throughout---no highs or low; no primer showing through. Allow the plate to dry completely before using.

Tips & Warnings

• Avoid all open flames; paint thinner and aerosol paint are extremely flammable.

• Do not store rags doused in paint thinner; they can spontaneously combust.

References

• United States Patent Office: Process For Cleaning Metal Surfaces; August 17, 1933
• Simple Green: Simple Green Concentrated Cleaner; Sunshine Makers Inc.; 2010