General Method Of Cleaning Nickel Silver
GENERAL METHOD OF CLEANING NICKEL SI= LVER
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
SPECIFIED IN THE SUMMARY.
A. This procedure includes guidance on cleaning nickel
silver building features to remove surface dirt and
B. Nickel silver is a nickel alloy usually containing
copper, nickel and zinc. Sometimes tin and lead
are also added to improve the casting properties of the
metal. Proportions vary depending on the type of nickel silver.
C. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing
this procedure and should be followed, when applicable,
along with recommendations from the Regional Historic
Preservation Officer (RHPO).
D. The cleaning approach should start with the most gentle means;
clean water with a natural fiber brush; and if needed nonionic detergent;
additionally an organic solvent may be needed.
A. Samples: Clean a representative sample area using
materials and methods specified at location specified by
the Contracting Officer. The samples accepted by the
Contracting Officer to serve as standard for the entire
job. They will be marked and left undisturbed.
A. Fisher Scientific Company
B. Industrial Soap
C. E.I. DuPont de Nemours Company, Inc.
NOTE: Chemical products are sometimes sold under a common
name. This usually means that the substance is not as pure as
the same chemical sold under its chemical name. The grade of
purity of common name substances, however, is usually adequate
for stain removal work, and these products should be purchased
when available, as they tend to be less expensive. Common
names are indicated below by an asterisk (*).
A. Degreaser/standard solvent such as turpentine, phosphoric
acid alcohols, mineral spirits or vinegar.
1. Phosphoric Acid:
a. A syrupy or deliquescent tribasic acid used
especially in preparing phosphates (as for
fertilizers), in rust-proofing metals, and as
a flavoring in soft drinks.
b. Other chemical or common names include
c. Potential Hazards: CORROSIVE TO FLESH;
CORROSIVE TO CONCRETE, STEEL, WOOD OR GLASS.
d. Available from chemical supply house or
2. Mineral Spirits:
a. A petroleum distillate that is used especially
as a paint or varnish thinner.
b. Other chemical or common names include
Benzine* (not Benzene); Naphtha*; Petroleum
spirits*; Solvent naphtha*.
c. Potential Hazards: TOXIC AND FLAMMABLE.
d. Safety Precautions:
1) AVOID REPEATED OR PROLONGED SKIN CONTACT.
2) ALWAYS wear rubber gloves when handling
3) If any chemical is splashed onto the
skin, wash immediately with soap and
e. Available from construction specialties
distributor, hardware store, paint store, or
printer's supply distributor.
3. Vinegar (white or clear):
a. Potential Hazards: CORROSIVE TO CONCRETE,
STEEL, WOOD OR GLASS.
b. Available from grocery store or supermarket.
c. Vinegar itself, which contains about 4% acetic
acid, may be suitable for some purposes
requiring acetic acid.
A mixture of 75% toluene, 24% acetone, and 1% butyl
Use a solvent normally used for thinning nitrocellulose
lacquers, such as DuPont Lacquer Solvent No. 3661-S (E.I.
DuPont de Nemours Company, Inc.) for use in
mid-temperature 50-80 degrees F, or approved equal.
B. Non-ionic detergent such as "Environtex Zyfo Cleaner", "Tergitol",
"Igepal CA-630", or approved
1. "Zyfo" cleaner concentrate, a controlled suds,
silicate buffered, non-ionic, rinseless-type
synthetic detergent, containing no soap, free
alkali, solvents, abrasives, acids, caustics or the
Try the following cleaning solution:
1. 7.5% thiourea solution (CS(NH2)2):
a. A colorless crystalline bitter compound
analogous to and resembling urea that is used
especially as a photographic and organic
b. Available from photographic supply distributor
(not camera shop).
2. 1% concentrated sulfuric acid
3. 0.5% detergent and wetting agent
4. 91% water; potable, non-staining and free of
materials detrimental to surfaces being cleaned
CAUTION: AVOID AQUEOUS AMMONIA, AMMONIUM SALTS (SCC),
HYDROGEN PEROXIDE (>10%) OR OXIDIZING ACIDS.
C. Corrosion Inhibitor/Cleaner: 1% Benzotriazole solution
in warm water - 40 g. Benzotriazole per gallon of water
(Fisher Scientific Company), or approved equal.
D. Clean, potable water
E. Distilled water
F. Clean, soft cloth
G. Plastic sheeting
A. Protection: Protect all surfaces immediately
adjacent to or below the area to be cleaned by covering
with polyethylene sheeting.
3.02 ERECTION, INSTALLATION, APPLICATION
A. Using a clean, soft cloth, wipe the surface with degreaser, rubbing with the grain of the metal. Clean
surface dirt and grease only, do not abrade the metal.
B. Wipe the surface with clean, soft cloth soaked with non-
ionic detergent or cleaning solution (see Section 2.02 B.
above), working a small area at a time.
C. Rinse the cleaned area with distilled water to remove
traces of cleaner and corrosion products which can
precipitate soon after cleaning.
D. Dry with a soft cloth.
E. After completion of cleaning, apply corrosion
inhibitor/cleaner on a clean soft cloth and rub along the
grain of the metal.
END OF SECTION