Absolutely. The KBS Tank Sealer System is ideal and used often for air compressor tanks. Air compressor tanks tend to rust because of condensation inside the tank and the KBS Tank Sealer System will prep the inside of the tank and seal it providing you rust protection so the condensation will not affect the integrity. Tank Sealer will also seal up and reinforce any pin holes that may already been in the tank.
NOTE: If you do have any holes, you will need to patch the holes with something like NuMetal Epoxy Putty which can withstand the pressure from the air compressor tank. After the holes have been patched well, then prep and seal the inside of the tank with the KBS Tank Sealer System.
KBS Tank Sealer System LINK --> https://www.kbs-coatings.com/kbs-tank-sealer-system
Please be sure you read and follow the complete application directions for Tank Sealer which can be found here -> https://www.kbs-coatings.com/tank-sealer-directions
Please reach back out if you have additional questions.