Historic Preservation - Technical Procedures
Cleaning And Polishing Bronze
Developed For Hspg (Nps - Sero)
Cleaning And Polishing Bronze
CLEANING AND POLISHING BRONZE
ALL CLEANING REMOVES SOME SURFACE METAL AND PATINA. THEREFORE, USE
CAUTION, AS EXCESSIVE CLEANING CAN REMOVE THE TEXTURE AND FINISH OF
THE CLEANING OR STRIPPING OF METALS MAY INVOLVE THE USE OF
ABRASIVES, LIQUIDS OR SOLVENTS WHICH MAY SPLASH OR RUN OFF ONTO
ADJACENT MATERIALS. TAKE SPECIAL CARE TO PROTECT ALL ADJACENT
MATERIALS, AND DO NOT USE THIS PROCEDURE ON METALS OTHER THAN
THOSE SPECIFIED IN THE SUMMARY.
A. This procedure includes guidance on the general cleaning
of dirt and oil on bronze.
B. For general information on the characteristics, uses and
problems associated with bronze, see 05010-03-S.
A. The Procter & Gamble Co.
P.O. Box 599
Cincinnati, OH 45202
B. Leo Silfen, Inc., Industrial Chemical Division
525 Fourth Avenue
Mt. Vernon, New York
NOTE: When the common name of a chemical is used on the
label, it is usually a sign that the substance is not as pure
as the same chemical sold under its chemical name. However,
the grade of purity of the common-name substance is almost
certain to be adequate for stain removal work, and because it
is likely to be less expensive, the common-name product should
be purchased when available. Common names are indicated by an
A. Mineral spirits:
1. Other chemical or common names include Benzine*
(not Benzene); Naphtha*; Petroleum spirits*;
2. Potential Hazards: TOXIC AND FLAMMABLE.
3. Safety Precautions:
a. AVOID REPEATED OR PROLONGED SKIN CONTACT.
b. ALWAYS wear rubber gloves when handling
c. If any chemical is splashed onto the skin,
wash immediately with soap and water.
4. Available from construction specialties
distributor, hardware store, paint store, or
printer's supply distributor.
B. Neutral detergent such a "Orvis" (Procter & Gamble), or
C. Marine Type Metal Polish Formula 90 (Leo Silfen, Inc.,
Industrial Chemical Division), or approved equal.
D. Clean, potable water
E. Lint-free wiping cloths
A. Soft natural bristle brushes (non-metallic)
B. Wooden scrapers
C. Fine bronze wool -or- Silicon carbide abrasive pads such
as "Scotch-Brite" (3M Company), or standard commercially
available pumice stone or stainless steel wool. DO NOT
USE STEEL WOOL, AS IT MAY PROMOTE DISCOLORATION OF THE
D. Rubber gloves
3.01 ERECTION, INSTALLATION, APPLICATION
NOTE: WHEN CLEANING, TRY TO RETAIN THE BRASS PATINA, AS THIS
PROTECTS THE BRASS FROM FURTHER CORROSION.
A. Remove loosely adhered soiling, such as bird droppings,
with wood scrapers before washing.
B. Remove more tenacious deposits with fine bronze wool.
C. Mix warm water (ONLY) with neutral detergent, or use
proprietary metal cleaner.
NOTE: AVOID CLEANING BRONZE WITH ALKALINE SOAPS THAT DO
NOT CONTAIN SODIUM HYDROXIDE, DETERGENTS CONTAINING
PYROPHOSPHATES SUCH AS "TIDE" OR AMMONIA SOLUTIONS
(ESPECIALLY ON LACQUERED SURFACES). THESE WILL
DETERIORATE THE COATING ON BRONZE.
D. Brush solution on bronze with soft natural bristle brush
(no metallic bristles) or a lint-free cloth. Rub along
the grain of the metal.
E. If dirt is greasy, dilute cleaning solution 1:1 with
F. Rinse thoroughly and dry with another lint free cloth.
G. Wash bronze periodically (twice a year) with a non-ionic
detergent such as "Orvis" (Procter & Gamble). Rinse with
distilled water and wipe dry with a clean soft cloth, to
prevent water spots and streaks.
H. For guidance on removing corrosion, removing lacquer and
reapplying a protective coating, see 05010-31-R and
END OF SECTION