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Removing Pollution, Industrial, Petroleum-based, and Miscellaneous Stains From Limestone And Marble
REMOVING POLLUTION, INDUSTRIAL, PETROLEUM-BASED, AND MISCELLANEIOUS STAINS FROM LIMESTONE AND MARBLE
THE CLEANING OR REMOVAL OF STAINS FROM STONE MAY INVOLVE THE USE
OF LIQUIDS, DETERGENTS OR SOLVENTS WHICH MAY RUN OFF ON ADJACENT
MATERIAL, DISCOLOR THE STONE OR DRIVE THE STAINS DEEPER INTO POROUS
STONES. USE THE PRODUCTS AND TECHNIQUES DESCRIBED HERE ONLY FOR
THE COMBINATIONS OF DIRT/STAIN AND STONE SPECIFIED.
PART 1---GENERAL
1.01 SUMMARY
A. This procedure includes guidance on the removal of
industrial stains from limestone and marble by poulticing
with a chemical solvent. Industrial stains include smoke
and soot, grease, oil, tar, asphalt, waxes, food stains,
and handmarks.
B. Industrial stains result from contact with such materials
as fuel oil, asphalt and tar. Industrial stains that
have penetrated deeply into the masonry should not be
rubbed in, but should always be removed with a poultice.
C. Some organic solvents that may be effective in removing
industrial stains include: naptha, mineral spirits,
chlorinated hydrocarbons (such as methylene chloride and
perchloroethylene), ethyl alcohol, acetone, ethyl
acetate, amyl acetate, toluene, xylene, and
trichlorethylene.
D. 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
3. Submittals
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).
E. For general information on the characteristics, uses and
problems associated with limestone, see 04460-01-S; for
marble, see 04455-01-S.
PART 2---PRODUCTS
2.01 MANUFACTURERS
A. The Procter & Gamble Co.
www.pg.com
2.02 MATERIALS
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. For Surface Stains:
1. Non-sodium based bleach
NOTE: DO NOT USE BLEACH ON DARK COLORED STONES AS
THIS WILL CAUSE THE STONE TO LIGHTEN.
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
mineral spirits.
3) If any chemical is splashed onto the
skin, wash immediately with soap and
water.
e. Available from construction specialties
distributor, hardware store, paint store, or
printer's supply distributor.
B. For Smoke and Soot:
1. Methyl Chloroform:
a. Other chemical or common names include 1,1,1-trichloromethane.
b. Potential Hazards: TOXIC.
IMPORTANT: Methyl chloroform is often known
as 1,1,1-trichloromethane. It has similar
solvent properties to trichlorethylene and
carbon tetrachloride whose usage is not
recommended on safety grounds. Care must be
taken with methyl chloroform although it is
much less hazardous than the other chemical
solvents mentioned. Ensure good ventilation
and/or respiratory apparatus.
c. Available from chemical supply house.
-OR-
Trisodium Phosphate (see Section 2.02 C.1. below)
C. For Grease, Oil, Foodstains or Handmarks:
1. Trisodium Phosphate:
NOTE: THIS CHEMICAL IS BANNED IN SOME STATES SUCH
AS CALIFORNIA. REGULATORY INFORMATION AS WELL AS
ALTERNATIVE OR EQUIVALENT CHEMICALS MAY BE
REQUESTED FROM THE ENVIRONMENTAL PROTECTION AGENCY
(EPA) REGIONAL OFFICE AND/OR THE STATE OFFICE OF
ENVIRONMENTAL QUALITY.
a. Strong base-type powdered cleaning material
sold under brand names.
b. Other chemical or common names include Sodium
Orthophosphate; Tribasic sodium phosphate;
Trisodium orthophosphate; TSP*; Phosphate of
soda*; (also sold under brand names such as).
c. Potential Hazards: CORROSIVE TO FLESH.
d. Available from chemical supply house, grocery
store or supermarket or hardware store.
-AND-
2. Sodium Perborate:
a. Other chemical or common names include
Perborax*.
b. Potential Hazards: TOXIC AND FLAMMABLE (WHEN
IN CONTACT WITH ORGANIC SOLVENTS).
c. Available from chemical supply house,
drugstore or pharmaceutical supply
distributor, grocery store or supermarket.
-OR-
3. Acetone (C3H6O):
a. A volatile fragrant flammable liquid ketone
used chiefly as a solvent and in organic
synthesis and found abnormally in urine.
b. Other chemical or common names include
Dimethyl ketone; Propanone
c. Potential Hazards: VOLATILE AND FLAMMABLE
SOLVENT
d. Available from chemical supply house or
hardware store.
-AND-
4. Amyl Acetate:
a. Other chemical or common names include Amyl
acetic ester; 1-pentanol acetate; Banana oil*;
Pear oil*.
b. Potential Hazards: FLAMMABLE.
c. Available from chemical supply house,
drugstore or pharmaceutical supply
distributor, paint store or photographic
supply distributor (not camera shop).
D. Suitable filler such as talc, chalk, clay, cotton pads,
or cotton flannel.
E. Neutral pH liquid soap such as "Joy" (Procter & Gamble),
or approved equal.
F. Clean, potable water
2.03 EQUIPMENT
A. Garden hose and pneumatic spray nozzle
B. Stiff bristle brushes (no iron wire)
C. Wood scrapers, knife blades and spatulas
PART 3---EXECUTION
3.01 ERECTION/INSTALLATION/APPLICATION
A. Removing Surface Stains:
1. Superficial (or surface) stains may be removed by
gently scrubbing with a scouring powder containing
bleach (none which are sodium-based) or water-based
household detergents that are acid and alkali-free.
NOTE: The use of bleach may depend on the color
and type of stone.
2. Brush with an emulsion of mineral spirits and rinse
with clean, clear water.
3. Allow to dry.
B. Removing Smoke and Soot:
1. Scrub stained area with a neutral pH liquid soap.
2. More stubborn patches may be pulled from the
masonry pores using a poultice based on methyl
chloroform; Another useful poultice contains
trisodium phosphate and bleaching powder.
For guidance on poulticing, see 04455-02-R.
C. Removing Grease, Oil, Food Stains or Handmarks:
1. Thoroughly scrub the surface with soap, non-abrasive
scouring powder and trisodium phosphate to
remove excess debris.
2. Apply a poultice of 1 part trisodium phosphate, 1
part sodium perborate, and 3 parts talc in a hot
neutral pH detergent solution in water. A useful
proprietary de-greasing caustic alkali cleaner is
available to break down greasy surface soiling,
particularly on surfaces exposed to pollution from
vehicles, and may be successfully used as a
preliminary preparation for cleaning by other
methods. Thorough removal from the surface is
essential. For guidance on poulticing, see 04455-02-R.
-OR-
1. Mix 1 part acetone and 1 part amyl acetate.
2. Soak a non-dyed cotton flannel in the solution and
place the flannel over the stain (clay may also be
used to form a pack).
3. Keep the flannel or the clay on the stain for three
days under a thin film of plastic.
4. Remove poultice with wooden spatulas or scrappers,
and thoroughly flush surface with mineral water.
END OF SECTION
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