FAQs

Q?

What is Efflorescence?

A.

Efflorescence is a white crystalline or powdery, often fluffy/fuzzy deposit on the surface of masonry materials like concrete, brick, clay tile, etc. It's caused by water seeping through the wall/floor/object. The water dissolves salts inside the object while moving through it, then evaporates leaving the salt on the surface.

Q?

My floors had a beautiful shine when new. How can I restore that new shine?

A.

If your floor is not deeply scratched, surface polishing may bring back an acceptable shine. However, existing scratches may remain. If your floor has worn badly, a complete restoration is warranted. This decision should be made between you and us.

Q?

Can you fix cracks in marble or other natural stone?

A.

Yes we can. Most cracks can be repaired to virtually invisible. However, it is important for us to also identify the source of the crack. It is possible there is an underlying problem that may need to be resolved.

Q?

Do you work with granite? We have a granite floor that is really in need of repair and restoration.

A.

Yes we do. As you may know, not all stone maintenance and restoration contractors do. Granite is more difficult to work with than marble and many other natural stones. Our services for granite include cleaning, polishing, sealing, repair, restoration, and maintenance. To learn more, visit our Granite services page.

Q?

How much dust will be created during the restoration of my floor?

A.

There is no dust created during the restoration process, because we use diamond abrasives and water.

Q?

Recently a cleaning firm spilled a cleaner that is obviously acid on my marble vanities. They were sealed, but the damage is still very evident in the form of hundreds of small circles. What would you recommend as the way to repair them, the materials to use, etc? Would it be better to replace the vanities?

A.

Sealing DOES NOT prevent etching. Sealing your stone inhibits staining. You do not need to replace your vanity tops. They can easily be repaired by Restoration Stoneworks.

Q?

I have a beautiful entry rug. Will it harm my stone floor?

A.

Rugs are a good idea to catch dirt and grit. However, there are a few things to keep in mind. It is important to use rug holders designed to go under rugs to keep them in place. Sliding rugs are not only dangerous, they are a constant source of new scratches. Do not use rugs that are backed with rubber or latex.

Q?

Why won’t the water spots on my marble or travertine clean up?

A.

These are likely not water spots, but an etch mark in the surface of the stone. This is what happens when an acidic substance comes in contact with any calcium based stone. To get rid of the etch marks, the stone will need to be polished out, much like a gemstone would have to be if it were scratched. If the etch mark is minor (i.e. you can see it, but can't really feel it with your finger) we recommend that you first try using a high quality Marble Polish. (See our  Caring For It page.) If the etching is more severe, you will need to have it professionally serviced. If this is the case, call us.

Q?

Where can I find information about caring for my stone?

A.

Please see our Caring For It page. You can download our Stone and Tile Care Guide from there. It provides a wealth of information pertaining to caring for your stone.

Q?

Is there routine, daily or weekly maintenance I should be performing?

A.

The #1 culprit of damage to floors is dirt, (grit, sand & dust). The best treatment for your floor is a dry, untreated microfiber dust mop or vacuum, used every day when possible. Damp mopping is recommended on a weekly basis and whenever there are visible spills. For more information about stone care, consult our page.

Q?

Our antique marble table top has some dull whitish areas that have developed over the years. Is this a problem you can fix?

A.

What you are describing sounds like etching. When acidic substances come in contact with marble and other calcite based stones, a chemical reaction occurs and what results is what you are describing. We can polish out the etching and restore your antique table top to its original state. To help prevent further damage, be sure to use coasters under drinks and clean up any spills as quickly as possible. Most importantly use only cleaning products designated safe for natural stone. Definitely don't use vinegar and water to clean your marble

Q?

I have a stain in my stone what should I do?

A.

Here is a great article in which we discuss stains and what can be done. [Stain removal on natural stone.]

Q?

Is moisture intrusion a problem for natural stone?

A.

Most of the problems associated with stone tile installation can be traced to moisture or water intrusion of some kind. Many stains are caused by the presence of water. Water is an essential ingredient for the setting cleaning and restoration of stone but it can also be its number one enemy. Read this article about the problems that are associated with moisture and water.

Q?

What does it mean that you are a Certified Stone and Tile PRO Partner?

A.

Stone and Tile PRO Partners are qualified stone professionals that are committed to professional integrity and business practices from delivering superior services using only quality products to maintaining their own ongoing education and training as well as educating their customers with sound information. A Stone and Tile PRO Partner has met stringent criteria including a list of verified references, proof of insurance, a health and safety program in place and an assurance that they meet all the state requirements to conduct business. Certified Stone and Tile PRO Partners provide support and consumer questions at stoneandtilepros.com "Ask Our PROS."

Q?

My stone countertops are no longer shiny. How do I get the shine back?

A.

Most of the time when a customer asks us why their countertop is not shiny anymore, it turns out that some sort of film is sitting on the surface. This happens when one does not use the proper cleanser, or when they clean their granite surface with water and dish soap. (This will eventually lead to soap film build up.) Give us a call. We can provide solutions for you.

Q?

I have heard some completely opposing views about sealing stone. What is your recommendation? Do we need to have our stone sealed…. or not??

A.

We get this question quite a bit. We believe that some stone must be sealed and other stone does not need to be sealed. It all depends on how porous the stone is. Maurizio Bertoli, considered by many to be the godfather of stone maintenance and restoration, was passionate about this topic and wrote a great article several years ago. We believe the article still holds true. You can read it here.

Q?

What is the “lemon juice” test you speak of for granite countertops?

A.

This test originated with Maurizio Bertoli. He wanted to give consumers a way to test different types of stones they were considering purchasing for their kitchen countertops. [Click here to see the Lemon Juice and Oil Test.]

Q?

My Granite Countertops are no longer shiny. How do I get the shine back?

A.

Most of the time when a customer asks us why their countertop is not shiny anymore, it turns out that some sort of film is sitting on the surface. This happens when one does not use the proper cleanser, or when they clean their granite surface with water and dish soap. (This will eventually lead to soap film build up.) Give us a call. We can provide solutions for you.

Q?

Does my stone require any special treatment different from my tile?

A.

YES. Ceramic and porcelain tile surfaces are much harder than your marble, limestone and travertine. These surfaces are acid sensitive and will wear and abrade when dust and dirt are ground underfoot.

Granite surfaces are harder, and with very few exceptions, impervious to acids. Still, proper care will help you maintain its beauty for years to come. You will want to insure your surface is sealed every other year or so to maintain stain resistance.

Q?

Can I put a hot pan on my granite counter top?

A.

Yes you can, although using a trivet or hot pad is recommended. Granite is naturally created under extreme heat and pressure. It will not be affected by residual heat from your frying pans, or baking sheets. Even a lit flame placed under a granite slab will not leave any scorch marks.

Q?

Advantage of Natural Stone

A.

Natural stone is by far and away the most respected covering material from a value added approach. Most people agree upon the elegance and sophistication of stone and thanks to rapid advances in industry technology stone is more affordable and practical then ever before. From the design point of view, natural stone can meet both traditional and contemporary schematics. As a completely natural material, stone brings its own authenticity and culture to your design while the great variations in color and texture allow for the most inspiring lay outs.

Aside from its unsurpassed genuine beauty, natural stone is extremely well built for covering applications. Granite, is second only to diamond on the hardness scale. This durability ensures that it does not blister, scratch, stain or crack. The cool, smooth polish of granite does not fade and will stand up to your sharpest knives and hottest pots.  Granites that  are sealed will to ensure years of maintenance free enjoyment. Clean up is easy with a natural cleaner. Natural stone is the pinnacle of form and function.

  • ADVANTAGES
  • Stain Resistant
  • Scratch Resistant
  • Heat Resistant
  • Acid Resistant
  • Highest in Clean Ability
  • Highest in Value Added
  • Natural Green Product
  • Low maintenance

Q?

Can yellow staining on White Carrera Marble be removed?

A.

I have had some cases where it is possible but it depends on how long the stain was there, if the moisture problem has been abated, etc. You can usually tell by the severity of the stain. If it’s dark, brown or red, chances are it won’t come out. If it a light yellow color it may be possible. Of course finding out the where the moisture is coming from is the most important. Even if you are able to remove the stain it can come back

Q?

What Kind of Sealer to Use for Natural Stone?

A.

In the service industry of stone restoration one of the most common requests is sealing to protect the surface of natural stone. A properly sealed natural stone surface; vanity, counter top or floor, will help the customer maintain their investment. We have found that a simple explanation of what a sealer actually is and more importantly how it will perform can be very useful. First and foremost, a well informed customer is important. Having the knowledge of some of the chemistry that goes into a sealer will be able help the service technician to answer the customer’s basic questions. This information can also be useful to determine whether the sealer has been misapplied or the wrong type sealer for a particular type of stone has been used.

The terminology “sealing’ can be confusing to the consumer. The most common definition of” sealer” and what most consumers believe is that the performance of a sealer is a coating or in the service trade known as a “film former” that when applied forms a protective film or coating on the surface of the stone, just like a coat of paint or varnish. While there are products out there that produce this effect it is merely a coating and is not designed to work as a true sealer or “Impregnating Sealer.”

Impregnating sealers (also known as penetrating sealers) are designed to penetrate below the surface and protect from within the stone while still allowing the miniscule pores of the stone to allow moisture vapor to escape. Impregnators reduce the pore size of the stone by filling the pores with solids typically made up of a resin. The resins are small enough to prevent complete blockage of the pores, so the stone will still allow vapor to pass through while not allowing a liquid to penetrate. When a stone's pores are completely blocked, moisture vapor will condense within the stone and the stone will be saturated with moisture. This can lead to a variety of problems such as spalling, iron oxidation and efflorescence.

Choosing what type of Impregnating Sealer to use.
Most Impregnating Sealers contain one of two main ingredients: A silicone derivative which is designed to repel water and a fluoro aliphatic resin derivatives such as polymers which repel both water and oil. Impregnating sealers can be water based or solvent based. Choosing the correct type can be very important to the performance of the sealer and the particular type of stone. In general solvent based sealers usually have smaller solids that will penetrate tighter grained stones. Water based sealers typically have larger” solids” which are better for more porous stones. Carefully determining what type of sealer to use can save many hours of time on site if the surface is soaking up the sealer like a sponge. The main job of a good impregnating sealer is to create a high surface tension so stains are not able to penetrate deep. This knowledge can save the service contractor a lot of money and time

Q?

How long will a stone sealer last?

A.

How long will a sealer last? What about the warranty claims made by manufacturers? There are plenty of claims, but it really comes down to proper application and maintenance. Homeowners should be aware that most warranties take effect ONLY when an accredited applicator seals your stone. Be sure that the applicator doing the work is reputable. It should be noted that any sealer on the market today that offers a warranty, the homeowner and/or applicator read what is warranted. Read the fine lines.

The wear and tear of daily use, exposure to the elements and maintenance plan all play a part in how long a sealer will last. A simple water porosity test to check the seal can be done by the customer:

Drip a tablespoon of water on the stone surface. Be sure to time the test. If the puddle darkens quickly, then sealing granite countertops is required. If it takes 3 or 4 minutes to darken a good impregnator sealer should be applied, sealing every 3-5 years should be fine and stains won't be an issue unless a staining material sits on the surface for a long period of time. If the puddle doesn't darken, then you have a stone that is next to impossible to stain. Sealing granite countertops in this category is really not necessary.

Assuring the customer that their stone surface is protected is the primary reason many professionals recommend applying granite sealer when in doubt or even if it really isn't needed.

For most granite material applying a sealer even when not needed won't present a problem. However, some dark granite material such as blacks and greens are very dense and if a sealer is applied, it sits on the surface without sinking into the stone and can noticeably dull the appearance. This can lead to having to refinish the stone or using strong chemicals to strip the surface. The best way to determine if the darker, denser stone material needs to be sealed is to drop a small amount of oil on the surface( in an inconspicuous area) and let it sit overnight. If the oil wipes up leaving no stain, then sealing isn’t necessary.          

Q?

What Does a Sealer Actually Do Anyway?

A.

A common term used by Stone Craftsmen to describe a stain deterrent that is applied to natural stone is "sealer". It's a general term that most consumers can relate to, and understand why it needs to be applied. In actuality the correct term is impregnator, however impregnating sealer, penetrating sealer seem to be used interchangeably . The name of the substance pretty much explains what it does. It penetrates into the stone and seals, but it seals without clogging the pores like a topical coating does. Instead an impregnator merely coats the pores of the stone allowing moisture vapor to escape, and letting the stone breathe. I know I know this has been said a million times, and most restoration professionals could recite it in their sleep, but do they actually know what occurs to make the impregnators work? Well in most cases only partially.

When a stone is impregnated properly what should the result be when liquid is placed on it? It should bead up, but why? Many would say it's because of the resins or solids in the particular impregnator, and they would be partially correct. What is the rest of the answer to complete the puzzle? The answer is in your chemistry books. You see Most liquids have a molecular make up that is positively charged, and most natural stones are negatively charged. The impregnator induces an ionic exchange which causes the surface of the stone to take on a positive charge. If you remember playing with magnets when you were a kid ( or maybe just yesterday lol) you'll remember that when you place the negative near the positive - smack they would attract - like liquid and stone. However if you placed the two like charges near each other you could slide them around the table all day and never get them to connect - like liquid beading up and rolling around on an impregnated natural stone.

So as you can see there is a little more that goes into the science of impregnators than just the delivery system, size of the solids, resins, oh and scent.

Categories

Natural Stone Cleaning , ‎ Natural Stone , ‎ Marble , ‎ Granite , ‎ Limestone

Q?

What Is The Difference Between “Honed” and, “Polished” Finish?

A.

A honed finish is a smooth matte finish, and a polished floor is a shine on the floor which can range from low to a high mirror finish, depending on what you want.

Q?

I have Marble Natural Stone floors in the kitchen. Some vinegar got on the floor and now we have a light spot. I believe that it is the sealer (polyurethane coating?) that got discolored. What is the best way to get rid of these dull spots and bring the normal shine back?

A.

When acid (vinegar) comes into contact with marble (calcium carbonate), it causes a chemical reaction. The result is called etching. Natural stone sealers penetrate the stone and do not prevent this natural reaction. If you do in fact have apolyurethane coat on top of your stone, then you have a different problem altogether. If the stone is etched, we can refinish

Q?

The Ten Most common Stone Problems

A.

The Ten Most common Stone Problems by Frederick M. Hueston

Marble, granite, limestone and other decorative stone are durable materials that will last a life time. However, if not installed correctly or properly cared for, will experience problems that will shorten its life. The following ten problems are the most common in dealing with stone.

1. Loss of shine

The loss of the high polish on certain marble and granite can be attributed to wear. This is especially true of marble, since it is much softer then granite. The bottoms of ones shoe acts like sandpaper on a stone floor surface and over time will wear the polish off. To prevent excessive wear it is important to keep the floor dust mopped, place walk off mats at all entrances. To repair a worn stone surface, it will be necessary to have a professional hone and polish it.>

2. Etching

The dull spot created when liquids containing acids are spilled on marble is called etching. Marble and limestone etch very easily. Granite is more acid-resistance and will rarely etch. To prevent etching, avoid using cleaners and chemicals that contain acids. Bathroom cleaners, toilet bowl cleaners and lemon cleaners commonly contain acids. Certain drinks and foods contain acids and will also etch. Light etching can be removed with a little marble polishing powder. Deep etching will require resurfacing of the stone.

3. Staining

All stone surfaces can become stained very easily. Most foods, drinks, ink, oil and rust will stain marble. Once a stone becomes stained, it can be very difficult to remove. To prevent staining clean the spilled material as soon as possible. Blot the spill with a clean paper towel or cloth. If this does not remove the stain then a process called “poulticing” may be needed. To prevent staining, sealing the stone with a good quality penetrating Hereto find a proven sealers.

4. Efflorescence

Efflorescence appears as a white powdery residue on the surface of the stone. It is a common condition on new stone installations or when the stone is exposed to a large quanity of water, such as flooding. This powder is a mineral salt from the setting bed. To remove efflorescence do not use water, buff the stone with a clean polishing or #0000 steel wool pad. The stone will continue to effloresce until it is completely dry. This drying process can take several days to as long as one year.

5. Spalling, Flaking & Pitting

If your stone is developing small pits or small pieces of stone are popping off the surface(spalling) then you have a problem. This condition is common on stone exposed to large amounts of water or when deicing salts are used for ice removal. Like efflorescence, mineral salts are the cause for spalling and pitting. Instead of the salts depositing on the surface(efflorescence) they deposit below the surface of the stone, causing pressure within the stone and therefore the stone spalls, flakes or pits. Unfortunately once a stone begins to spall it is almost impossible to repair. It is recommended that the stone be replaced.

6. Yellowing

There are several reasons why a stone will turn yellow: Embedded dirt and grime can give the stone a yellow, dingy look. Waxes and other coatings can yellow with age. Certain stones will naturally yellow with age. This is caused by oxidation of iron within the stone and especially problematic with white marbles.
If the yellowing is caused by dirt or wax build up, clean the stone with an alkaline cleaner or wax stripper. If the yellowing is the result of aged stone or iron oxidation, live with it, it is not coming out.

7. Uneven Tile-Lippage

Lippage is the term given to tiles that are set unevenly. In other words the edge of one tile is higher then the next. Lippage is the result of a poor installation. If the lippage is higher than the thickness of a nickel, it is considered excessive and the tile will have to be ground to flaten the floor. This will require the services of a professional stone refinishing contractor.

8. Cracks

Cracks in stone tiles can be caused by settling, poor installation, excessive vibration, especially if you live in California, etc.
Cracks can sometimes be repaired by filling with a color matched polyester or epoxy. Before a crack is repaired, it is wise to find out how and why the cracked occurred in the first place otherwise it may crack again.

9. White stun Marks

Stun marks appear as white marks on the surface of the stone and are common in certain types of marble. These stuns are the result of tiny explosions inside the crystal of the stone. Pin point pressures placed on the marble cause these marks. Women’s high heels or blunt pointed instruments are common reasons for stun marks.
Stun marks can be difficult to remove. Grinding and/or honing can reduce the number of stuns, but some travel through the entire thickness of the stone.

10. Water Rings/Spots

Water rings and spots are very common on marble table tops. These spots are hard water minerals such as calcium and magnesium. These minerals are left behind when the water evaporates leaving a ring or a spot. To remove these spots use a marble polishing powder. Deep spots may require honing. To prevent spots on counters and table tops, frequently apply a good stone paste wax.

Other Stone Problems

Many problems can occur with stone surfaces. The above ten are the most common. The following is a quick problem solving technique that will help identify other stone problems that might be encountered.

1. Identify the problem- Is it discolored, etched, cracked or what?
2. Cause of the problem- What happened to cause the problem? Identifying the cause will often lead to the solution.
3. Stone Type- Identify the stone type. Is it marble, granite, limestone, slate, etc.?
4. Installation- check the installation, is it installed properly?
5. Age- How long has the problem existed? Old problems are difficult to impossible to cure.
6. Maintenance Procedures- How is the stone being maintained? Could the maintenance or lack of, caused the problem?
7. Test the Solution- Perform a small test in an inconspicuous area to decide if your proposed cure will work effectively.

Q?

Granite Polishing

A.

Most companies are not equipped or educated to work on granite. The only method they know is waxing to make a shine. Waxes = Fake Shine. It does not last and can only get worse over time. You can think of it as waxing a surfboard rather than a car. It collects dirt & debris, wears unevenly, and smudges.

The proper technique to polishing granite is mechanically with the use of abrasives and plain water. Granite is harder than calcite based stones such as marble, limestone, and travertine. Therefore, more physical effort is needed. Heat, psi, and rpm along with the proper abrasives and machinery can attain a natural high polished shine that will last forever with the proper maintenance which is very easy and inexpensive.

Q?

Stain Removal Guide

A.

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.