EPO is an acronym for Expanded Polyolefin. This material is typically used in new construction as a flame retardant, although it is also sometimes used to create components of radio-controlled lightweight aeroplanes and is most known for its use in self-skinned footwear, such as Crocs. Regardless of its uses, EPO has one important characteristic that applies to painting: it is easily damaged by petroleum-based paint. To generate a lasting finish that won't damage the underlying Expanded Polyolefin, use a water-based paint.
Wash the Expanded Polyolefin foam with soap, using rags. Don't use a chemical cleanser on EPO, or you may damage the foam; instead, use a water-based cleanser.
Rinse the Expanded Polyolefin foam with wet rags. Leave no soapy residue behind, or primer adhesion will prove poor. Let the EPO dry for two hours.
Cover surfaces adjacent to the Expanded Polyolefin foam, using masking paper. Fasten the paper in place, using nothing else but a low-tack professional painter's tape. Don't use other types of tape, or traces of adhesive may stay behind after removal.
Cover surfaces under the Expanded Polyolefin foam with dust sheets. Avoid plastic dust sheets which will allow wet spray paint overspray to pool.
Coat the EPO with a water-based latex spray primer. Encourage slick results by maintaining approximately eight inches between the Expanded Polyolefin foam and spray tip. Let the EPO dry for two hours.
Coat the EPO with a water-based latex spray paint or acrylic spray enamel. Encourage slick results by maintaining approximately eight inches between the Expanded Polyolefin foam and spray tip. Let the EPO dry for two hours.
You may also use a polyester paintbrush prime and paint larger sections of Expanded Polyolefin foam. Use acrylic spray enamel on EPO foam subject to duress.
Don't use oil-based primer or paint, or the EPO foam will melt.