How to Dry Compressed Air

We open the drain located in the bottom of the tank of the Dewalt compressor all the time. However, when we want to dry something off with compressed air, we are still getting the parts all wet. What should we do, is there a water trap or filter recommended? This compressor is used in a body shop where my Formula S is being restored. I don't want to tell the owner what to do, but I don't want H2O mixed into my paint formula. Thank you.

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