A cartridge assembly for use with a spray gun, the spray gun for applying an elastomeric sealant coating, the cartridge assembly comprising: a body having a first compartment and a second compartment, the first compartment containing a first component, the second compartment containing a second component, the body dimensioned to engage the spray gun, and a mixing straw engaged to the first and second compartments, the mixing straw configured to receive and when the cartridge assembly is engaged with the spray gun and the spray gun is energized, combine the first and second components to form an uncured sealant mix and emit the uncured sealant mix, under pressure, from a tip of the mixing straw at a removed end thereof to form a visibly clear, cured in place, elastomeric sealant coat on an aircraft workpiece, the clear elastomeric sealant coat being one of a polyurea, polyurethane or polyurea, polyurethane hybrid coat; wherein the cured elastomeric sealant coat is resistant to at least one of a phosphate ester based hydraulic fluid wherein the maximum weight change of said visibly clear elastomeric sealant is not more than plus or minus 18% after submersion for twenty four hours of the said visible clear elastomeric sealant in the phosphate ester based hydraulic fluid, a mineral oil based hydraulic fluid or a synthetic hydrocarbon based hydraulic fluid wherein the maximum weight change of said visibly clear elastomeric sealant is not more than plus or minus 10% after submersion for twenty four hours of the said visible clear elastomeric sealant in the mineral oil based hydraulic fluid or a synthetic hydrocarbon based hydraulic fluid and wherein the maximum weight change of said visibly clear elastomeric sealant is not more than plus or minus 8% after submersion for twenty four hours of the said visible clear elastomeric sealant in the Jet A fuel. a body having a first compartment and a second compartment, the first compartment containing a first component, the second compartment containing a second component, the body dimensioned to engage the spray gun, and a mixing straw engaged to the first and second compartments, the mixing straw configured to receive and when the cartridge assembly is engaged with the spray gun and the spray gun is energized, combine the first and second components to form an uncured sealant mix and emit the uncured sealant mix, under pressure, from a tip of the mixing straw at a removed end thereof to form a visibly clear, cured in place, elastomeric sealant coat on an aircraft workpiece, the clear elastomeric sealant coat being one of a polyurea, polyurethane or polyurea, polyurethane hybrid coat; wherein the cured elastomeric sealant coat is resistant to at least one of a phosphate ester based hydraulic fluid wherein the maximum weight change of said visibly clear elastomeric sealant is not more than plus or minus 18% after submersion for twenty four hours of the said visible clear elastomeric sealant in the phosphate ester based hydraulic fluid, a mineral oil based hydraulic fluid or a synthetic hydrocarbon based hydraulic fluid wherein the maximum weight change of said visibly clear elastomeric sealant is not more than plus or minus 10% after submersion for twenty four hours of the said visible clear elastomeric sealant in the mineral oil based hydraulic fluid or a synthetic hydrocarbon based hydraulic fluid and wherein the maximum weight change of said visibly clear elastomeric sealant is not more than plus or minus 8% after submersion for twenty four hours of the said visible clear elastomeric sealant in the Jet A fuel.