Abstract: Method and system for applying liquid sealant in holes of a structural member prior to installing fasteners in such holes, which comprises mixing air with a liquid sealant, spraying a controlled amount of the resulting air-sealant mixture into the holes and depositing liquid sealant therein, and impinging an elevated pressure air stream on the deposited liquid sealant to spread the sealant out and produce a thin layer of sealant in the holes. A system for carrying out the method comprises a spray gun having separate air and liquid sealant paths which meet at the spray nozzle of the spray gun to achieve the mixing of air with the liquid sealant.