Historic Preservation - Technical Procedures
- Removing Old Lacquer Or Paint From Solid Brass Or Brass-Plate
- Procedure code:
- HSPG Prepared For NPS - Southeast Regional Office
- Metal Materials
- Last Modified:
- Removing Old Lacquer Or Paint From Solid Brass Or Brass-Plate
- Last Modified:
REMOVING OLD LACQUER OR PAINT FROM SOLID BRASS OR BRASS-PLATE
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
SPECIFIED IN THE SUMMARY.
A. This procedure includes guidance on removing deteriorated
lacquer or paint from brass-plate or solid brass.
B. For additional guidance relating to cleaning and
maintaining brass, see the following procedures:
1. For cleaning and polishing solid brass, see 05010-10-P.
2. For removing old lacquer or paint from solid brass
or brass-plate, see 05010-31-R.
3. For removing patina or tarnish from solid brass,
4. For applying a protective coating to brass-plate or
solid brass, see 05010-12-P.
C. Brass is an alloy of copper and zinc. Brass-plate is a
thin layer of brass bonded to steel. Solid brass is more
durable than brass-plate and, therefore, can withstand
more rigorous methods of cleaning.
D. Brass may be unfinished or lacquered. Architectural
brass hardware and trim is generally maintained in a
highly polished, "bright" finish.
1. Unfinished brass MUST be polished frequently in
order to maintain its luster. All polishing,
however, removes some brass.
2. Lacquered brass will usually last about 10 years
and does NOT require frequent polishing.
3. Lacquer protects the brass finish from
deterioration, though some brilliance of its
surface characteristics is sacrificed. Removal and
reapplication of the lacquer, however, will not
harm the brass surface.
E. 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).
A. Diedrich Technologies, 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. Household items such as ammonia, vinegar, baking soda and
1. Household ammonia:
CAUTION: DO NOT MIX AMMONIA WITH CHLORINE
BLEACHES, A POISONOUS GAS WILL RESULT! DO NOT USE
BLEACH ON BIRD DROPPINGS.
a. Other chemical or common names include
Ammonium Hydroxide; Ammonia water*; Aqua
b. Potential hazards: TOXIC; MAY IRRITATE THE
c. Available from chemical supply house, grocery
store or pharmaceutical supply distributor, or
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.
3. Baking soda:
a. Other chemical or common names include Sodium
bicarbonate; baking powder*.
b. Available from grocery store or supermarket,
or drugstore or pharmaceutical supply
Mild cleaner such as "Mr. Clean"
Commercial paint and lacquer remover, such as "Diedrich
400 - Enviro-Safe Strip" (Diedrich Technologies, Inc.),
or approved equal.
1. A volatile fragrant flammable liquid ketone used
chiefly as a solvent and in organic synthesis and
found abnormally in urine.
2. Other chemical or common names include Dimethyl
3. Potential Hazards: VOLATILE AND FLAMMABLE SOLVENT
4. Available from chemical supply house such as Fisher
Scientific Co. or hardware store.
B. Mineral spirits:
1. A petroleum distillate that is used especially as a
paint or varnish thinner.
2. Other chemical or common names include Benzine*
(not Benzene); Naphtha*; Petroleum spirits*;
3. Potential Hazards: TOXIC AND FLAMMABLE.
4. 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.
5. Available from construction specialties
distributor, hardware store, paint store, or
printer's supply distributor.
C. Mild soap
D. Clean, potable water
E. Clean, soft cloths
A. Eye and skin protection
B. Heavy gloves and protective gear
C. Soft natural bristle brushes
A. Before proceeding with steps to clean brass, examine the
surface(s) to determine the extent of the work required.
1. Broken, cracked, missing, distorted or loose parts.
2. Coating failures such as chips, losses, peeling,
cracks, bubbling and wear.
3. Corrosion - caused by moisture, sea water and sea
air, deicing salts, acids, soils, gypsum plasters,
magnesium oxychloride cements, ashes, clinkers and
1. General: Comply with recommendations of
manufacturers of cleaners, polishes and coatings
for protecting building surfaces against damage
from exposure to their products.
2. Protect adjacent surfaces from contact with
chemical cleaners by covering them with liquid
strippable masking agent or polyethylene film and
waterproof masking tape. Apply masking agent to
comply with manufacturer's recommendations. Do not
apply liquid masking agent to porous surfaces.
3. Protect persons and surrounding surfaces of
building where metal surfaces are being restored,
from damage resulting from metal cleaning and
a. Prevent cleaning solutions and coatings from
coming into contact with persons and other
surfaces which could be damaged by such
b. Erect temporary protection covers over
walkways for persons who must be in area of
operations during course of metal cleaning and
c. Provide ventilation to eliminate the spread of
fumes to unaffected spaces.
B. Surface Preparation:
1. Before cleaning, determine if your brass surface is
solid or plated:
a. A magnet will stick to the steel beneath brass
plating; it will not stick to solid brass.
b. Solid brass can withstand much harsher
treatment than brass plating can.
3.03 ERECTION, INSTALLATION, APPLICATION
NOTE: WHEN CLEANING, TRY TO RETAIN THE BRASS PATINA, AS THIS
PROTECTS THE BRASS FROM FURTHER CORROSION.
A. Remove coating using a chemical stripper, such as lacquer
thinner, paint stripper or acetone.
1. Apply stripper to the brass surface with a stiff
bristle brush or roller. Stroke the brush or
roller along the grain of the metal.
NOTE: DO NOT USE STEEL WOOL TO APPLY LACQUER
REMOVER. STEEL WOOL IS OFTEN TREATED WITH
CORROSION INHIBITORS WHICH CAN STAIN COPPER BASE
CAUTION: ALWAYS WEAR GLOVES AND WORK IN A WELL
VENTILATED AREA WHEN USING CHEMICAL STRIPPERS.
2. Allow the stripper to dwell for a length of time as
recommended by the manufacturer.
3. Carefully remove loosened coating and stripper from
the surface using a trowel, broad-knife or scraper.
4. Remove the residue left by the stripper with
mineral spirits and/or mild soap and water.
Completely submerge brass item in one of the following
1. One part ammonia and two parts hot water, or
2. Four tablespoons baking soda and one quart water
(bring this mixture to a boil), or
3. Solution of Mr. Clean.
Place the brass to be cleaned in a stainless steel or
1. Cover the brass with white vinegar, then pour on a
coating of regular table salt (sprinkle so that all
areas are touched).
2. Simmer on low heat for 10 to 15 minutes.
3. Remove brass item with tongs; Buff with a clean,
soft cloth; Rinse well, dry, and rebuff to a satiny
A. During the work, remove from the site discarded cleaning
and coating materials, rubbish, cans and rags at end of
each work day.
B. Upon completion of coating work, remove all protective
coverings and coatings, and clean window glass and other
coating-spattered surfaces. Remove spattered coatings by
proper methods as recommended by coating manufacturer,
using care not to damage adjacent surfaces.
END OF SECTION