Repairing A Scratched Or Worn Incralac Coating On Bronze
- Procedure code:
- Outdoor Sculpture Manual - Center For Public Buildings
- Metal Materials
- Last Modified:
REPAIRING A SCRATCHED OR WORN INCRALAC COATING ON BRONZE
A. This procedure includes guidance on selectively repairing
damaged or worn areas of the protective acrylic resin
coating (Incralac) on bronze.
B. Incralac is designed to be applied by spray. Brush
applied coatings are not recommended, as they tend to be
thicker and contain flaws created by the movement of the
brush hairs through the resin during application. Both
factors reduce the durability of the coating. When a
brush-applied coating begins to deteriorate, it will
deteriorate first along the brush-hair excursions and
thereby produce numerous crevices in the coating where
corrosion can occur, visible as a fine network of green
C. Perform repair work as needed when the Incralac coating
is damaged or missing.
D. For general information on the characteristics, uses and
problems associated with bronze, see 05010-03-S.
A. Stanley Chemical Co.
401 Berlin Street
East Berlin, CT 06023
B. Conservation Materials
P.O. Box 2884
Sparks, NV 89431
C. Maas & Waldstein Co.
Division of Seagroves Coatings Corp.
P.O. Box 187
320 Paterson Plank Road
Carlstadt, NY 07072
D. Custom Aerosal Packaging
128 East Water Street
Piqua, OH 45356
E. Fisher Scientific Company
711 Forbes Avenue
Pittsburgh, PA 15219
800/388-8355 or 412/562-8300
F. Procter & Gamble Co.
P.O. Box 599
Cincinnati, OH 45202
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. Acrylic lacquer such as "Incralac" (Stanley Chemical
Co.), (Conservation Materials), (Maas & Waldstein Co.),
(Custom Aerosal Packaging), or approved equal. Available
in spray cans or 5-gallon drums.
B. Polyethylene dispersion, added to final Incralac coating
to produce desired degree of matt/glossy appearance,
(71X-202 polyethylene dispersion) (Stanley Chemical Co.),
or approve equal.
C. 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.
D. Mild detergent such as "Ivory", "Joy" or "Thrill"
(Procter & Gamble Co.), or approved equal. Available in
supermarket or drugstore.
E. Clean, potable water
F. Sponges and soft towels or rags
A. For large areas of coating deterioration, bulk
application with power spray equipment is more effective.
The following equipment is recommended:
1. Spray gun, Binks or DeVilbiss with accessories; for
example, DeVilbiss bleeder, external mix gun with
cup, or approved equal.
2. Air compressor, small, portable, either gas (for
exterior use) or electric (if electricity is
accessible), or electric compressor powered by a
3. Accessories: air hoses adequate for reaching all
parts of the metal, couplers, repair kit for spray
gun, small moisture traps.
B. Organic vapor masks, basic safety equipment to protect
operator from breathing vapors or organic solvents during
C. Goggles, to protect operator's eyes from organic solvent
D. Gloves, neoprene rubber or polyethylene disposable
gloves. Skin contact with solvent or Incralac should be
3.01 ERECTION, INSTALLATION, APPLICATION
A. If bronze has a protective wax coating over the Incralac,
use mineral spirits or other appropriate solvent to
remove wax from affected area.
B. Wash area to be recoated to remove all surface dirt,
grease and foreign matter including flaking Incralac
1. Wipe the surface with a clean cloth saturated in
clean, clear water and mild detergent. DO NOT
FLOOD ENTIRE SURFACE, SIMPLY WIPE AFFECTED AREA.
2. Thoroughly rinse the surface with clean, clear
water and allow to dry.
C. Apply clear protective coating within 4 hours of cleaning
operations. For small areas use Incralac in a spray can.
Large areas will require the use of power spray
NOTE: BRUSH-APPLIED COATINGS DO NOT PROVIDE UNIFORM
1. Apply first coat in a thin mist. Allow to dry.
2. Apply two additional wet coats, allowing minimum
thirty minutes drying time between each coat.
3. Minimum thickness of Incralac coating shall be 1
D. If Incralac coating has a protective wax finish, apply
wax as directed in procedure 05010-06-P, "Applying Cold
Microcrystalline Wax to Bronze".
END OF SECTION