You need to purchase lacquer for brass in an aerosol can. HD and Lowes don't carry it, but an Ace Hardware or equivalent will. It yields a transparent, very glossy finish. I used it on my pump tags and brass/copper fire extinguisher. Don't use it when the humidity is over 60% or it will cloud up. I learned that first hand. I then waited until the humidity was below 50%, sprayed it again and the lacquer liquified and the moisture disappeared. Use several of thin coats.