Poulticing Plywood Or Joint Sealant Stains From Concrete
- Procedure code:
- Hstrc Concrete: Investigation & Rpr/Pre-Conf Training - 1989
- Concrete Cleaning
- Last Modified:
POULTICING PLYWOOD OR JOINT SEALANT STAINS FROM CONCRETE
THE CLEANING OR REMOVAL OF STAINS FROM CONCRETE MAY INVOLVE THE
USE OF LIQUIDS, DETERGENTS OR SOLVENTS WHICH MAY RUN OFF ON
ADJACENT MATERIAL, DISCOLOR THE CONCRETE OR DRIVE THE STAINS DEEPER
INTO POROUS CONCRETE. USE THE PRODUCTS AND TECHNIQUES DESCRIBED
HERE ONLY FOR THE COMBINATIONS OF DIRT/STAIN AND CONCRETE SPECIFIED.
A. This procedure includes guidance on poulticing pink
stains from concrete produced by plywood or joint
B. The alkalies in concrete may react with phenol-formaldehyde
resins in plywood or with the phenolics used in some
joint sealants to form pink staining compounds.
C. Safety Precautions:
1. DO NOT save unused portions of stain-removal
2. DO NOT store any chemicals in unmarked containers.
3. EXCELLENT VENTILATION MUST BE PROVIDED WHEREVER ANY
SOLVENT IS USED. USE RESPIRATORS WITH SOLVENT
4. No use of organic solvents indoors should be
allowed without substantial air movement. Use only
spark-proof fans near operations involving
5. Provide adequate clothing and protective gear where
the chemicals are indicated to be dangerous.
6. Have available antidote and accident treatment
chemicals where noted.
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. For additional information on poulticing, see 04455-02-R.
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 (*).
NOTE: THESE SOLUTIONS BLEACH COLORED CLOTHING AND CAN BE
CORROSIVE TO METALS.
A. Sodium Hypochlorite (NaOCl):
1. An unstable salt produced usually in aqueous
solution and used as a bleaching and disinfecting
2. Other chemical or common names include Bleaching
solution*; Household bleach*; Laundry bleach*;
Solution of chlorinated soda*.
3. Potential Hazards: CORROSIVE TO FLESH.
4. Available from chemical supply house, grocery store
or supermarket, hardware store or janitorial supply
1. Potential Hazards: CORROSIVE TO FLESH.
2. Available from chemical supply house or hardware
Javelle Water: Made by user, see 03710-02-S for guidance
1. Calcium Hypochlorite (CaCl2O2):
a. A white powder used especially as a bleaching
agent and disinfectant.
b. Other chemical or common names include
Chlorinated calcium oxide; Bleaching powder*;
Calcium oxymuriate*; Chloride of lime*;
Chlorinated lime*; Hypochlorite of lime*;
Oxymuriate of lime*.
c. Potential Hazards: CORROSIVE TO FLESH;
FLAMMABLE (WHEN IN CONTACT WITH ORGANIC
d. Available from chemical supply house, dry
cleaning supply distributor, drugstore or
pharmaceutical supply distributor, janitorial
supply distributor, swimming pool supply
distributor, or water and sanitation supply
2. Sodium Carbonate (Na2CO3):
a. A sodium salt of carbonic acid used especially
in making soaps and chemicals, in water
softening, in cleaning and bleaching and in
photography; A hygroscopic crystalline
anhydrous strongly alkaline salt.
b. Other chemical or common names include
Carbonate of soda*; Sal soda*; Soda*; Soda
ash*; Washing soda*.
c. Available from chemical supply house, grocery
store or supermarket, hardware store, paint
store, or water and sanitation supply
B. Filler material such as diatomaceous earth or talc
C. Mineral water
D. Clean dry towels for blotting the area after treatment
E. Scouring powder
F. Clean, potable water
G. Accessible source of water, soap and towels for washing
and rinsing in case of emergencies associated with the
use of chemicals
A. Glass or ceramic container for mixing the solution
B. Wooden utensil for stirring the ingredients
C. Wood or plastic spatula
D. Stiff bristle brush (non-metallic)
1. Provide adequate wash solutions (i.e. water, soap
and towels) before starting the job.
2. Whenever acid is used, the surface should be
thoroughly rinsed with water as soon as its action
has been adequate. Otherwise it will continue
etching the concrete even though the stain is gone.
3.02 ERECTION, INSTALLATION, APPLICATION
NOTE: DO NOT TRY MORE THAN ONE TREATMENT ON A GIVEN AREA
UNLESS THE CHEMICALS USED FROM PRIOR TREATMENT HAVE BEEN
A. Mix 1 part hypochlorite solution (diluted with 4 to 6
parts water) with enough talc to make a thick paste.
1. Select the amount of talc to make a poultice of the
required size. Add hypochlorite solution to obtain
the proper paste-like consistency.
2. The undiluted hypochlorite solution can be
commercial household bleach (which is about 5%
sodium hypochlorite) or 5% potassium hypochlorite
solution or Javelle water. For guidance on making
javelle water, see 03710-02-S.
B. Thoroughly wet the concrete surface to be treated with
clean, clear water.
C. Apply the poultice mixture to the stained area using a
wood or plastic spatula and allow to dry. Be sure to
spread the poultice well beyond the stained area. The
liquid portion of the paste will migrate into the
concrete where it will dissolve some of the staining
material. Then the liquid will gradually move back
beyond the concrete surface and into the poultice, where
it will evaporate, leaving the dissolved staining
material in the poultice.
D. When the poultice has dried, brush or scrape it off with
a wooden scraper.
E. Using a stiff bristle brush, scrub the surface with
scouring powder and clean water to remove any residual
F. Thoroughly rinse the area with clean, clear water and
allow to dry.
G. Repeat the process as necessary to achieve the desired
level of cleanliness.
END OF SECTION