Many shops commonly apply self etching primer to bare metal surfaces. Most polyester fillers and Epoxy primers should not be applied directly over self etching primers. So what do you apply, if you need additional filling? Feather Fill G2 is the answer. This sprayable polyester filler is used over properly prepped steel, galvanized steel, aluminum, fiberglass, SMC, OEM finishes, body filler AND 1K and 2K Self Etching Primers. Includes liquid catalyst. Sprays wit your primer gun with 1.7-2.2mm nozzle. High solids, high build provides an excellent foundation for any paint system. Eliminates body filler staining.