Out-of-autoclave (OOA) laminates sometimes exhibit significant surface porosity (or “pinholes”) on the tool-side surface. This porosity can be corrected using surface films, gel coats, or primer/paint, but these require additional time, money and weight. Surface films are also not easily applicable to complex or curved molds, increasing the presence of the issue in parts that are not flat. We are currently working to understand the fundamental physical phenomena behind this defect and feasible methods for controlling or eliminating it.
Surface porosity observed using video microscopy on the surface of a OOA prepreg composite laminate (Cycom 5320, T650-35 5HS carbon fabric).