The fully saturated hydrocarbon backbone of EPDM rubber results in outstanding weatherability, UV stability, and low/high temperature resistance. Therefore EPDM rubber has been established as the primary polymer choice for automotive sealing applications (both dense and sponge weather strip). A typical manufacturing process of automotive dense weatherstrip involves profile extrusion followed by continuous vulcanization. Excessive porosity in extruded and fully cured dense profiles remains a big challenge to many automotive weatherstrip Tier suppliers. Dow’s new Advanced Molecular Catalyst (AMC) and polymerization process technology advancements enable enhanced molecular structure design of EPDM. Furthermore, significant research efforts were directed to understand how the rubber formulation and processing parameters affect the final EPDM rubber products. A factory mixing and extrusion trial was conducted to develop a technical package for dense profile based on NORDEL™ EPDM that is free of porosity. This report summarizes the effects of a) Compound Formulation; b) Extrusion Conditions; and c) Vulcanization Conditions, on the porosity of the final extruded dense profile and present a porosity free solution for EPDM dense profile.