Cleaning - Carbon expanded metal is lightly oiled and should be cleaned before finishing. The most common cleaning method is an acid or solvent bath with a water rinse. For aluminum, use a non-etching chemical or detergent, then rinse and dry thoroughly.
Anodizing - A surface treatment for aluminum where an oxide coating is added electrochemically to the metal. For interior abrasion resistance a .0025" coating is necessary. Medium abrasion applications for interior or maintained exteriors need a .0004" coating. Use a .0008" coating for exteriors.
Porcelain Enamel - Porcelain enamels can be readily applied to expanded metal. Forming, cutting, welding and drilling should be done before applying the finish. All surfaces should be covered.
Painting, Lacquering- Plastic Coating - Be sure the coating used has good surface tension or wetting properties and viscosity to prevent any pullback from metal edges and webbing-in of diamonds.
Galvanizing - Hot dip galvanizing is primarily a protective coating and may have a rough uneven appearance. Where smooth finish is required, other coatings and protective methods should be used. Certain small expanded metal styles do not lend themselves to hot dip galvanizing because the openings become filled with zinc. Warping or distortion may occur during hot dip galvanizing due to the heat of the molten zinc.For these reasons patterns lighter than 18 gauge, with openings of 1/2" or less or any patterns with a weight per square foot of 0.45 lbs or less are not recommended to be galvanized.