Non-Marring Coating for Composites

Question:

We are a manufacturer of carbon fiber composites and are producing a test article for a military application. We need a highly durable, preferably flat (non-reflecting) paint for long-term exterior exposure and lots of handling. We would like the paint to be non-marring, so that we can fingernail drag over the surface and it does not show as with most flat paints. We prefer to use waterborne, low-VOC systems obviously. We have spray and oven facilities. G. W

Answer:

Quit looking, G. W.! Quit looking now! The coating you are looking for is commercially available. Although I don’t know the Mil Spec. number, I’m sure it has one already assigned but not sure about waterborne. Since the coating is based on polyurethane technology, it should have the desired mar resistance. If your carbon fiber surface is resin-rich, you may be able to apply it directly to the carbon fiber composites. Otherwise, you will need a primer to accommodate any stray fibers. It is important that the surface be cleaned to remove any contaminants. As you know, (here I go again) poor surface preparation is the greatest single cause of paint adhesion failure. You can save yourself a lot of grief by using an approved material These coating are available from suppliers listed under Coatings, military and government specification, on page 286 and 287, of the 2004 Products Finishing Directory & Technology Guide www.pfonline.com/suppliers.html).