Chemical Surface Preparation Methods
Chemicals can be used to prepare the surface of the brass piece. Protective finishes over the pure brass such as lacquer and varnish as well as surface dirt and oils can be dissolved with a chemical solvent.
Acetone, methyl alcohol, paint remover or lacquer thinner will remove the protective film. If the piece is small, it can be soaked completely in a container filled with the solvent. A larger piece can be coated with the solvent using a paint brush and allowing the chemical time to dissolve the coating. Make sure you get into all the cracks and crevices. Several coatings may be needed to remove all of the lacquer. These chemicals will also remove any grease, fingerprints and dirt from the piece. They are corrosive. Use gloves and work in a well ventilated area. Follow the manufacturer's instructions.
If there is no protective film of lacquer coating, a simple cleaning may suffice using less harsher methods that are available. A good washing with soap and water may be sufficient for surface preparation. A mild solution of water and vinegar or rubbing alcohol can also be used. Wipe the piece with a soft cloth soaked in the cleaning solution. Be sure to get into all the engravings and hard to reach places. These household cleaning supplies are readily available and very safe to use.
The piece should be thoroughly dried prior to proceeding with antiquing process. A hair dryer, propane torch, a heat gun or an oven can be used. Once prepared, the material should then be handled carefully to avoid re-contaminating the piece with dirt and oils.