Plastic Media Blast Paint Stripping

Question:

I work for a company that overhauls helicopter components. We are currently exploring alternative methods (over chemical strippers) to remove paint from components and have been researching Plastic Media Blasting (PMB). PMB appears to be an effective and efficient way of removing paint and is used by many in the aviation field. However, I have encountered a warning that PMB is not recommended for use on components that will require a subsequent Fluorescent Penetrant Inspection (FPI), due to the possible peening effect that PMB may have on the surface of the metal. Unfortunately many of our components do require an FPI after paint removal, as part of the overhaul process. Is there another effective dry media or other method of paint removal other than a chemical stripper that may work for our situation? A. H.

Answer:

In Plastic Media Blast stripping, the rules dictate using a media that removes the paint without harming the substrate. I am sure the suppliers of both blasting equipment and media are aware of the effects of the various types of media on various coatings and substrates. The parameters include media size, composition, nozzle shape, angle of attack and air pressure.
For the record, other dry media include sand, nut shells, corn husks, fruit seeds, glass beads, steel shot and carbon dioxide pellets. Each has its advantages and disadvantages. There are also pyrolytic stripping methods. Notable among these is laser stripping that uses a laser beam to pyrolyze organic coatings. One size doesn’t fit all. The media must be chosen to remove your paint from your substrate.