Historic Preservation - Technical Procedures
Poulticing Iodine Stains From Concrete
Hstrc Concrete: Investigation & Rpr/Pre-Conf Training - 1989
Poulticing Iodine Stains From Concrete
POULTICING IODINE STAINS FROM CONCRE= TE
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 THE POROUS CONCRETE. USE THE PRODUCTS AND TECHNIQUES
DESCRIBED HERE ONLY FOR THE COMBINATIONS OF DIRT/STAIN AND
A. This procedure includes guidance on removing iodin= e
stains from concrete. Iodine stains generally fade and
disappear with time. However, if immediate removal is
desired, a poultice containing denatured alcohol may be
used in stain removal.
B. 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 substanti= al air movement. Use only
spark-proof fans near operations involving
5. Provide adequate clothing and protective gear where
the chemicals are indicat= ed to be dangerous.
6. Have available antidote and accident treatment
chemicals where noted.=0C 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 Precaution= s
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 adequa= te
for stain removal work, and these products should be purchas= ed
when available, as they tend to be less expensive. Com= mon
names are indicated below by an asterisk (*).
A. Denatured Alcohol:
1. Other chemical or common names include Methylated
2. Potential hazards: TOXIC AND FLAMMABLE.
3. Available from hardware store, paint store or
printer's supply distribu= tor.
4. Denatured alcohol, which carri= es no liquor tax,
should be a satisfactory substitute for ethyl
alcohol for stain removing purposes.
B. Filler material such as whiting, diatomaceous earth or
C. Mineral water
D. Clean dry towels for blotting the area after treat= ment
E. Clean, potable water
F. Accessible source of water, soap and towels for washing
and rinsing in case of emergencies assoc= iated 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
1. Provide adequate wash solutions (i.e. water, soap
and towels) before starti= ng 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 whiting material from Section 2.01 with denatu= red
alcohol to create a thick paste. S= elect the amount of
whiting or filler material to make a poultice of the
required size. Add denatured alcoh= ol to obtain the
proper paste-like consistency.
B. Thoroughly wet the concrete surface to be treated with
clean, clear water.
C. Apply the poultice 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 migrates into the concrete
where it will dissolve some of the stain= ing 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
D. When the poultice has dried, brush or scrape it off with
a wooden scraper.
E. Thoroughly rinse the area with clean, clear water and
allow to dry.
F. Repeat the process as necessary to sufficiently remove
END OF SECTION