Oh, those nasty stains! How do you go about removing that red stain from the fruit drink your son spilled on the floor? What do you use to remove black marker ink from your white marble floor? Does lipstick stain? The list can go on and on.
Any spill should be cleaned as soon as possible. Blot spills with a paper towel or clean rag. At this stage, it is important only to blot; wiping a spill may spread it over a larger area, making a larger mess. Use only cold water and stone soap or a neutral cleaner. Rinse the area several times. If a stain is still present, a chemical poultice may have to be applied.
Avoid using chemicals of any kind until you know which chemical cleaner to use. (See "Choosing a Chemical" below) Certain chemicals will react with the spilled material and could make the stain permanent.
Marble, granite and certain ceramic tile are porous materials. If not thoroughly sealed, they will stain. The only way a stain can be removed is to literally pull it out of the stone or ceramic with both a chemical and material that will absorb the stain. This chemical absorbent-material combination is what we call a poultice.
Poultices are commonly powder or cloth materials that can be mixed with a chemical and placed on top of the stain. Refer to the table below for some of the more common poultice materials. Clays and diatomaceous earth are safe and readily available, but do not use whiting or clays containing iron with an acidic chemical; iron will react with the acid, and may cause rust staining. It is best to purchase powders that are designed specifically for stone and tile. Consult a stone restoration specialist or your stone supplier if in doubt.
Clays such as Attapulgite, Kaolin, Fuller's Earth
Talc Chalk (whiting)
Sepiolite (hydrous magnesium silicate)
How to apply a poultice
Before you attempt to remove a stain, it is extremely important to know what has caused it. If you don't know, I would recommend that you consult a stone specialist, or refer to my book on stain removal for a detailed description of the procedure.
To apply a poultice, take the following steps:
1. Clean the stained area with water and stone soap. Remember to blot rather than wipe.
2. Pre-wet the stained area with a little water. Distilled water is recommended.
3. Refer to the chart below and determine which chemical to use for the stain.
4. Mix the poultice material with the selected chemical. Mix until a thick peanut-butter paste consistency is obtained.
5. Apply the paste to the stained area, overlapping the stain by at least ¼". Do not make the application too thick, or it will take a long time to dry.
6. Cover the paste with a plastic sandwich bag or food wrap. Tape the plastic using a low-contact tape.
7. Allow the paste to sit for 12–24 hours.
8. Remove the plastic cover and check to see if the paste has dried. If it has not, allow it to sit uncovered until thoroughly dry.
9. Once it is dry, remove the paste by scraping and rinse the area.
10. Examine the stain. If it still remains, but is somewhat lighter, re-poultice until it is gone. If the stain refuses to disappear completely, it is time to give up, replace the tile or call a stone specialist.
Stain removal can be very difficult, and care must be taken when using a poultice.
Choosing a Chemical
|Coffee and tea||Hydrogen Peroxide|
|Ink, magic marker, etc.||Methylene Chloride (use with extreme care)|
|Oil||Ammonia or a degreaser|
Please use extra caution when handling all chemicals listed above. Thoroughly read Material Safety Data Sheets for each chemical before use.
Marble or Granite?
I am building a new house and would like to use some type of stone for my kitchen countertops. Is marble or granite best?
Both marble and granite can be used for a kitchen counter but each has its advantages and disadvantages. Marble is available in an unlimited number of colors. It scratches very easily though. If you are going to be cutting meats and vegetables marble is a poor choice. Granite is very scratch resistant and will take cutting, however granite can be very porous and if you are doing a lot of cooking with hot oil, granite can stain easily. Granite can be protected against staining if you seal it with a good quality stone sealer. Most kitchen stone kitchen countertops are granite and overall is a good choice.
Is granite acid resistant?
Warning: There is one acid that will severely etch, pit and dull a polished granite surface. This acid is known as Hydrofluoric acid (HF) and is found in many rust removers. If you have experienced etching on granite surfaces, and you are using such a product, you may want to check the label and see if it contains Hydrofluoric acid. If it does, the granite may need to be repaired.
Black Granite Fading
I have received numerous calls lately concerning the fading of black granite counter tops. Why does black granite fade?
The answer is, black granite should not fade. Black granite imported from Asia is sometimes Doctored with dyes and oils to darken the surface. The fading is nothing more than the dyes and oils being removed. Unfortunately, the only fix is to re-polish the top. This can be costly.
Before purchasing a granite top perform the following test to find out if it has been doctored.
Take a clean white rag and apply a some acetone to the surface of the granite. If any residue or black color is observed on the top, do not accept it, it has been dyed.
Rust is one of the most difficult stains to remove from marble, granite and other stone surfaces. Many of the rust removers available in stores can damage stone. We have found a great method for removing rust stains.
A product called Iron Out is available from most home centers and hardware stores. This product is a white powder that is designed for removing iron from water softeners, but also works great for removing iron and other metal stains from stone.
To remove iron stains mix I part Iron Out to 2 parts poultice powder (diatomaceous earth). Add water until you get a soupy consistency. Apply this mixture to the iron stain, cover with plastic and let it sit for 24 hours. After 24 hours remove the poultice and reapply if necessary.
For more information on iron and other stain removal see the book Stain Removal Guide for Stone, available from The National Training Center for Stone & Masonry Trades at 800-841-7199.