Current polysulfide based aircraft primers have excellent flexibility/elongation properties and do not fail around seams and fasteners.  These primers, however, do not comply with the stringent emission regulations set forth by NESHAP due to excess VOC content.  Additionally, these primers cure slowly under humid conditions and reduce the weatherability of topcoat/primer system due to migration of un-reacted polysulfide into the topcoat.  In response to these deficiencies, Infoscitex proposes to develop a flexible, low VOC, rapid curing polysulfide (FLVRC) primer coating that has four hour pot life after mixing, cures to tack-free, walk-on status within 4-8 hours under humid conditions and is compatible with current chromate-free corrosion inhibitors. The FLVRC coating will be designed to be compatible with the MIL-PRF-85285D topcoat standard and will provide >60% GE impact elongation and excellent adhesion. This will be accomplished by formulating a flexible, rapid-cure, chemically-modified polysulfide binder resin that addresses the issues associated with previous polysulfide coatings.  Phase I efforts will focus primarily upon developing the FLVRC, preparing low VOC spray-coated test panels and demonstrating adhesion, flexibility and topcoat compatibility.  In Phase II, the FLVRC primer will be refined to further reduce VOC/HAPS as well as replace Chromium (VI) corrosion inhibitors with environmentally-compliant materials.