As a general rule, any fibre or particle larger that 15 microns will form a visible blemish if it is located on or very close to the surface of a gloss finish. Contamination can occur during the manufacture or application of paints and in some cases can be caused by the deposition of material during service.
Examples of contaminants that we have identified include gelled resin particles introduced during paint manufacture, fibres from spray booth air filters deposited during motor vehicle refinishing and iron dust from a machine shop eating into the surface of paint on cars parked nearby. Those interested in more details on the subject please contact us.
This is one area of analysis where success depends on a clear understanding of the circumstances that resulted in contamination. Our first task is always to obtain as many reference samples of suspect contaminants as possible. We find that the most useful techniques for identifying the contaminants, once they have been dissected from the film, are FTIR, SEM-EDS and polarised light microscopy.