Removing Unknown Stains From Marble Using The "Nest" Method
- Procedure code:
- Outdoor Sculpture Manual - Center For Public Buildings
- Last Modified:
REMOVING UNKNOWN STAINS FROM MARBLE USING THE "NEST" METHOD
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.
A. This procedure includes guidance on preparing a general
paste for removing unknown stains from marble. This
method of application is useful for applying solvent or
bleaching chemicals to graffiti or stains on horizontal
stone surfaces. For removal of a specific stain type,
see the appropriate procedure(s) as listed below:
1. Copper/Bronze Stains: See 04400-07-R.
2. Greasy Smudges: See 04455-10-R.
3. Oil and Fat Stains: See 04455-11-R.
4. Etch Marks: See 04455-15-R.
5. Ink and Dye Stains: See 04455-18-R.
6. Organic Stains: See 04455-14-R.
7. Linseed Oil Paints: See 04455-12-R.
8. Latex and Acrylic Paints: See 04455-13-R.
9. Rust Stains: See 04400-06-R.
10. Iodine Stains: See 04455-16-R.
11. Urine Stains: See 04455-17-R.
B. 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).
C. For general information on the characteristics, uses and
problems associated with marble, see 04455-01-S.
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. Solvent such as trichloroethylene (highly refined
CAUTION: TRICHLOROETHYLENE IS HIGHLY TOXIC AND MAY REACT
WITH STRONG ALKALIS SUCH AS FRESH CONCRETE TO FORM
1. Other chemical or common names include Ethinyl
2. Potential Hazards: TOXIC.
3. Available from automotive supply distributor,
chemical supply house (both commercial and
scientific), dry cleaning supply distributor, paint
store, photographic supply distributor (not camera
shop), or printer's supply distributor.
B. Molding plaster
C. Mineral water
D. Clean, lint-free cloths
A. Waterproof container for mixing the paste
B. Wooden spoon or spatula
C. Wooden scraper (for removing the mold)
3.01 ERECTION, INSTALLATION, APPLICATION
A. Pour a moderate amount of mineral water into the
B. Add a small amount of molding plaster to the water.
C. Stir the mixture, continue adding plaster and stirring
until the solution has the consistency of toothpaste.
D. Mold the paste like a bird's nest and place it on the
stain. Be sure the mold covers the entire stain and
parts of the unsoiled stone surrounding the entire stain.
E. Allow the nest to dry (approximately 30 minutes).
F. Pour some solvent into the nest and allow to set for
about three hours.
G. After the set period, remove the mold with a wooden
scraper (to avoid scratching the surface).
H. Thoroughly rinse the surface thoroughly with mineral
I. Blot the surface with clean, lint-free cloths and allow
it to dry completely.
J. If residual staining remains, repeat the treatment until
the entire stain has been removed.
END OF SECTION