What causes white residues after conformal coating?  The coating is an acrylic and after the first coat there appears to be a white residue and after the 24 hour cure the coating appears very dull and still has some of the white residues.  The residues almost look like water flux residue but it isn't.  The supplier that the coating was purchased from says it is strictly humidity related and only a cosmetic issue.  There is no visible loss of adhesion.  The solder mask is a LPI matte finish.  Can this be part of the problem?