GENERAL
CARE
Care and Precautions
Use coasters under all glasses, particularly those
containing alcohol or citrus juices. Many common foods
and drinks contain acids that will etch or dull the
surface of many stones. Do not place hot items directly
on the stone surface. Use trivets or mats under hot
dishes and placemats under china, ceramics, silver or
other objects that can scratch the surface.
Cleaning Procedures and Recommendations
Floor Surfaces
Dust mop interior floors frequently using a clean non-treated
dry dust mop. Sand, dirt and grit do the most damage
to natural stone surfaces due to their abrasiveness.
Mats or area rugs inside and outside an entrance will
help to minimize the sand, dirt and grit that will scratch
the stone floor. Be sure that the underside of the mat
or rug is a non-slip surface. Normally, it will take
a person about eight steps on a floor surface to remove
sand or dirt from the bottom of their shoes. Do not
use vacuum cleaners that are worn. The metal or plastic
attachments or the wheels may scratch the surface.
Other Surfaces
Clean stone surfaces with a few drops of neutral cleaner,
stone soap (available at hardware stores or from your
stone dealer) or a mild liquid dishwashing detergent
and warm water. Use a clean rag mop on floors and a
soft cloth for other surfaces for best results. Too
much cleaner or soap may leave a film and cause streaks.
Do not use products that contain lemon, vinegar or other
acids on marble or limestone. Rinse the surface thoroughly
after washing with the soap solution and dry with a
soft cloth. Change the rinse water frequently. Do not
use scouring powders or creams; these products contain
abrasives that may scratch the surface.
Bath and Other Wet Areas
In the bath or other wet areas, soap scum can be minimized
by using a squeegee after each use. To remove soap scum,
use a non-acidic soap scum remover or a solution of
ammonia and water (about 1/2 cup ammonia to a gallon
of water). Frequent or over-use of an ammonia solution
may eventually dull the surface of the stone.
Vanity Top Surfaces
Vanity tops may need to have a penetrating sealer applied.
Check with your installer for recommendations. A good
quality marble wax or non-yellowing automobile paste
wax can be applied to minimize water spotting.
Food Preparation Areas
In food preparation areas, the stone may need to have
a penetrating sealer applied. Check with your installer
for recommendations. If a sealer is applied, be sure
that it is non-toxic and safe for use on food preparation
surfaces. If there are questions, check with the sealer
manufacturer.
Outdoor Pool & Patio Areas
In outdoor pool, patio or hot tub areas, flush with
clear water and use a mild bleach solution to remove
algae or moss.
STONE IDENTIFICATION
Know Your Stone
Natural stone can be classified into two general categories
according to its composition: siliceous stone or calcareous
stone. Knowing the difference is critical when selecting
cleaning products.
Siliceous stone is composed mainly of silica or quartz-like
particles. It tends to be very durable and relatively
easy to clean with mild acidic cleaning solutions. Types
of siliceous stone include granite, slate, sandstone,
quartzite, brownstone and bluestone.
Calcareous stone is composed mainly of calcium carbonate.
It is sensitive to acidic cleaning products and frequently
requires different cleaning procedures than siliceous
stone. Types of calcareous stone include marble, travertine,
limestone and onyx. What may work on siliceous stone
may not be suitable on calcareous surfaces.
How to Tell the Difference
A simple acid sensitivity test can be performed to determine
whether a stone is calcareous or siliceous. You will
need about 4 oz. of a 10% solution of muriatic acid
and an eye-dropper. Or you can use household vinegar
and an eyedropper. Because this test may permanently
etch the stone, select an out of the way area (a corner
or closet) and several inches away from the mortar joint.
Apply a few drops of the acid solution to the stone
surface on an area about the size of a quarter. If the
stone is calcareous, the acid drops will begin to bubble
or fizz vigorously. If little or no reaction occurs,
the stone can be considered siliceous. Rinse the area
thoroughly with clean water and wipe dry. This test
may not be effective if surface sealers or liquid polishes
have been applied. If an old sealer is present, chip
a small piece of stone away and apply the acid solution
to the fractured surface. CAUTION: Muriatic acid is
corrosive and is considered to be a hazardous substance.
Proper head and body protection is necessary when acid
is used.
Stone Finishes
A polished finish on the stone has a glossy surface
that reflects light and emphasizes the color and marking
of the material. This type of finish is used on walls,
furniture tops and other items, as well as floor tiles.
A honed finish is a satin smooth surface with relatively
little light reflection. Generally, a honed finish is
preferred for floors, stair treads, thresholds and other
locations where heavy traffic will wear off the polished
finish. A honed finish may also be used on furniture
tops and other surfaces.
A flamed finish is a rough textured surface used frequently
on granite floor tiles.
Stone Colors and Appearance
Granites and marbles are quarried throughout the world
in a variety of colors with varying mineral compositions.
In most cases, marbles and granites can be identified
by visible particles at the surface of the stone. Marble
will normally show "veins" or high concentrations.
The minerals in granite will typically appear as small
flecks distributed uniformly in the stone. Each type
of stone is unique and will vary in color, texture and
marking.
Sandstones vary widely in color due to different minerals
and clays found in the stone. Sandstone is light gray
to yellow or red. A dark reddish brown sandstone, also
called brownstone, has commonly been used in the northeastern
United States and eastern Canada. Bluestone is a dense,
hard, fine-grained sandstone of greenish-gray or bluish-gray
color and is quarried in the eastern United States.
Limestone is a widely used building stone with colors
typically light gray, tan or buff. A distinguishing
characteristic of many limestones is the presence of
fossils that are frequently visible in the stone surface.
Slate is dark green, black, gray, dark red or multi-colored.
It is most commonly used as a flooring material and
for roof tiles and is often distinguished by its distinct
cleft texture.
STAINS
Spills and Stains
Blot the spill with a paper towel immediately. Don't
wipe the area, it will spread the spill. Flush the area
with plain water and mild soap and rinse several times.
Dry the area thoroughly with a soft cloth. Repeat as
necessary. If the stain remains, refer to the section
in this brochure on stain removal.
Stain Removal
Identifying the type of stain on the stone surface is
the key to removing it. If you don't know what caused
the stain, play detective. Where is the stain located?
Is it near a plant, a food service area, an area where
cosmetics are used? What color is it? What is the shape
or pattern? What goes on in the area around the stain?
Surface stains can often be removed by cleaning with
an appropriate cleaning product or household chemical.
Deep-seated or stubborn stains may require using a poultice
or calling in a professional. The following sections
describe the types of stains that you may have to deal
with and appropriate household chemicals to use and
how to prepare and apply a poultice to remove the stain.
Types of Stains and First Step
Cleaning Actions
OIL-BASED
(grease, tar, cooking oil, milk, cosmetics)
An oil-based stain will darken the stone and normally
must be chemically dissolved so the source of the stain
can be flushed or rinsed away. Clean gently with a soft,
liquid cleanser with bleach OR household detergent OR
ammonia OR mineral spirits OR acetone.
ORGANIC
(coffee, tea, fruit, tobacco, paper, food, urine, leaves,
bark, bird droppings)
May cause a pinkish-brown stain and may disappear after
the source of the stain has been removed. Outdoors,
with the sources removed, normal sun and rain action
will generally bleach out the stains. Indoors, clean
with12% hydrogen peroxide (hair bleaching strength)
and a few drops of ammonia.
METAL
(iron, rust, copper, bronze)
Iron or rust stains are orange to brown in color and
follow the shape of the staining object such as nails,
bolts, screws, cans, flower pots, metal furniture. Copper
and bronze stains appear as green or muddy-brown and
result from the action of moisture on nearby or embedded
bronze, copper or brass items. Metal stains must be
removed with a poultice.(See section on Making &
Using a Poultice) Deep-seated, rusty stains are extremely
difficult to remove and the stone may be permanently
stained.
BIOLOGICAL
(algae, mildew, lichens, moss, fungi)
Clean with diluted (1/2 cup in a gallon of water) ammonia
OR bleach OR hydrogen peroxide. DO NOT MIX BLEACH ANDAMMONIA!
THIS COMBINATION CREATES A TOXIC AND LETHAL GAS!
INK
(magic marker, pen, ink)
Clean with bleach or hydrogen peroxide (light colored
stone only!) or lacquer thinner or acetone (dark stones
only!)
PAINT
Small amounts can be removed with lacquer thinner or
scraped off carefully with a razorblade. Heavy paint
coverage should be removed only with a commercial "heavy
liquid" paint stripper available from hardware
stores and paint centers. These strippers normally contain
caustic soda or lye. Do not use acids or flame tools
to strip paint from stone. Paint strippers can etch
the surface of the stone; re-polishing may be necessary.
Follow the manufacturer's directions for use of these
products, taking care to flush the area thoroughly with
clean water. Protect yourself with rubber gloves and
eye protection, and work in a well-ventilated area.
Use only wood or plastic scrapers for removing the sludge
and curdled paint. Normally, latex and acrylic paints
will not cause staining. Oil-based paints, linseed oil,
putty, caulks and sealants may cause oily stains. Refer
to the section on oil-based stains.
WATER SPOTS AND RINGS
(surface accumulation of hard water)
Buff with dry 0000 steel wool.
FIRE AND SMOKE DAMAGE
Older stones and smoke or fire stained fireplaces may
require a thorough cleaning to restore their original
appearance. Commercially available "smoke removers"
may save time and effort.
ETCH MARKS
Etch marks are caused by acids left on the surface of
the stone. Some materials will etch the finish but not
leave a stain. Others will both etch and stain. Once
the stain has been removed, wet the surface with clear
water and sprinkle on marble polishing powder, available
from a hardware or lapidary store, or your local stone
dealer. Rub the powder onto the stone with a damp cloth
or by using a buffing pad with a low-speed power drill.
Continue buffing until the etch mark disappears and
the marble surface shines. Contact your stone dealer
or call a professional stone restorer for refinishing
or re-polishing etched areas that you cannot remove.
EFFLORESCENCE
Efflorescence is a white powder that may appear on the
surface of the stone. It is caused by water carrying
mineral salts from below the surface of the stone rising
through the stone and evaporating. When the water evaporates,
it leaves the powdery substance. If the installation
is new, dust mop or vacuum the powder. You may have
to do this several times as the stone dries out. Do
not use water to remove the powder; it will only temporarily
disappear. If the problem persists, contact your installer
to help identify and remove the cause of the moisture.
SCRATCHES AND NICKS
Slight surface scratches may be buffed with dry 0000
steel wool. Deeper scratches and nicks in the surface
of the stone should be repaired and re-polished by a
professional.
Poultices
Making and Using a Poultice
A poultice is a liquid cleaner or chemical mixed with
a white absorbent material to form a paste about the
consistency of peanut butter. The poultice is spread
over the stained area to a thickness of about 1/4 to
1/2 inch with a wood or plastic spatula, covered with
plastic and left to work for 24 to 48 hours. The liquid
cleaner or chemical will draw out the stain into the
absorbent material. Poultice procedures may have to
be repeated to thoroughly remove a stain, but some stains
may never be completely removed.
Poultice Materials
Poultice materials include kaolin, fuller's earth, whiting,
diatomaceous earth, powdered chalk, white molding plaster
or talc. Approximately one pound of prepared poultice
material will cover one square foot. Do not use whiting
or iron-type clays such as fuller's earth with acid
chemicals. The reaction will cancel the effect of the
poultice. A poultice can also be prepared using white
cotton balls, whitepaper towels or gauze pads.
Cleaning Agents or Chemicals
OIL-BASED STAINS
Poultice with baking soda and water OR one of the powdered
poultice materials and mineral spirits.
ORGANIC STAINS
Poultice with one of the powdered poultice materials
and 12% hydrogen peroxide solution (hair bleaching strength)
OR use acetone instead of the hydrogen peroxide.
IRON STAINS
Poultice with diatomaceous earth and a commercially
available rust remover. Rust stains are particularly
difficult to remove. You may need to call a professional.
COPPER STAINS
Poultice with one of the powdered poultice materials
and ammonia. These stains are difficult to remove. You
may need to call a professional.
BIOLOGICAL STAINS
Poultice with dilute ammonia OR bleach OR hydrogen peroxide.
DO NOT MIX AMMO-NIA AND BLEACH! THIS COMBINATIONCREATES
A TOXIC AND LETHAL GAS!
Applying the Poultice
Prepare the poultice. If using powder, mix the cleaning
agent or chemical to a thick paste the consistency of
peanut butter. If using paper, soak in the chemical
and let drain. Don't let the liquid drip.
Wet the stained area with distilled water.
Apply the poultice to the stained area about1/4 to
1/2 inch thick and extend the poultice beyond the stained
area by about one inch. Use a wood or plastic scraper
to spread the poultice evenly.
Cover the poultice with plastic and tape the edges
to seal it.
Allow the poultice to dry thoroughly, usually about
24 to 48 hours. The drying process is what pulls the
stain out of the stone and into the poultice material.
After about 24 hours, remove the plastic and allow the
poultice to dry.
Remove the poultice from the stain. Rinse with distilled
water and buff dry with a soft cloth. Use the wood or
plastic scraper if necessary.
Repeat the poultice application if the stain is not
removed. It may take up to five applications for difficult
stains.
If the surface is etched by the chemical, apply polishing
powder and buff with burlap or felt buffing pad to restore
the surface.
Do's and Dont's
DO Dust mop floors frequently
DO Clean surfaces with mild detergent or stone soap
DO Thoroughly rinse and dry the surface after washing
DO Blot up spills immediately
DO Protect floor surfaces with non-slip mats or area
rugs and countertop surfaces with coasters, trivets
or placemats
DON'T Use vinegar, lemon juice or other cleaners containing
acids on marble, limestone, travertine or onyx surfaces
DON'T Use cleaners that contain acid such as bathroom
cleaners, grout cleaners or tub & tile cleaners
DON'T Use abrasive cleaners such as dry cleansers or
soft cleansers
DON'T Mix bleach and ammonia; this combination creates
a toxic and lethal gas
DON'T Ever mix chemicals together unless directions
specifically instruct you to do so
Call your professional stone supplier, installer or
a restoration specialist for problems that appear too
difficult to treat.
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