Stain removal Possible ?

[altheg]

Hi,
I have a marble trimmed fireplace with a 3/4" marble slab hearth. I had a roof leak that made the wood subfloor collect water near the fireplace. The marble hearth now has stains from the wood showing on the top surface (this is a basic white marble with greyish waves, don't know the exact name). Is it possible to remove the stain or would I have to replace the marble because the stain started on the back side ?

Thanks

	Marble MARBLE: CHARACTERISTICS This standard includes general information on the characteristics and common uses of marble and identifies typical problems associated with the material. INTRODUCTION Marble is an extremely hard, metamorphic stone composed of calcite (CaCO3). It is formed as a result of the recrystallization of limestone under the intense pressure and heat of geologic processes. The effect of this process is the creation of a stone with a very tight crystalline structure and small but definite porosity. Because of its structure, marble can take a very high polish and is a very popular decorative stone for architectural and sculptural uses. The limited porosity of marble, especially polished marble, makes it less vulnerable to the leaching effects of water. Calcium carbonate, however, of which marble is composed, is highly susceptible to attack by acidic agents. Marble is readily dissolved by acids, even very dilute acids, however the actual results of acidic exposure will vary with the nature of the acid. Chlorides, nitrates, sulfates and other chemical compounds react differently with marble and produce various by-products, which have a wide range of solubility and impact on the durability of marble. For this reason, it is always important to determine the exact type of pollutants causing marble deterioration. Marble itself can be of two types, one composed of calcite and the other of dolomite. Dolomitic marble is much more resistant to acid attack than calcite marble. The color of marble ranges from the brilliant white of calcite to black, including blue-gray, red, yellow and green, depending upon the mineral composition. TYPICAL USES Marble has many decorative and structural uses. It is used for outdoor sculpture as well as for sculpture bases; in architecture it is used in exterior walls and veneers, flooring, decorative features, stairways and walkways. The way in which the stone is used may be a factor in limiting or controlling the severity of exposure. The use or function of the marble may also affect the feasibility of applying certain treatments, but type of use is not the primary factor in the major types of deterioration and damage to which marble is susceptible.

[kdnoel]

Dry it up and use a poultice. The stain should come up after a few times.

	Poultice This operation takes a minimum of twenty-four hours to extract foreign materials (stains) from most natural stones.

[Huligar]

Can you post a picture of the damage stone?

[Koessler]

As Jo mentioned, a picture would help. What color is the stain? Do you know what the marble is set over?

	Marble MARBLE: CHARACTERISTICS This standard includes general information on the characteristics and common uses of marble and identifies typical problems associated with the material. INTRODUCTION Marble is an extremely hard, metamorphic stone composed of calcite (CaCO3). It is formed as a result of the recrystallization of limestone under the intense pressure and heat of geologic processes. The effect of this process is the creation of a stone with a very tight crystalline structure and small but definite porosity. Because of its structure, marble can take a very high polish and is a very popular decorative stone for architectural and sculptural uses. The limited porosity of marble, especially polished marble, makes it less vulnerable to the leaching effects of water. Calcium carbonate, however, of which marble is composed, is highly susceptible to attack by acidic agents. Marble is readily dissolved by acids, even very dilute acids, however the actual results of acidic exposure will vary with the nature of the acid. Chlorides, nitrates, sulfates and other chemical compounds react differently with marble and produce various by-products, which have a wide range of solubility and impact on the durability of marble. For this reason, it is always important to determine the exact type of pollutants causing marble deterioration. Marble itself can be of two types, one composed of calcite and the other of dolomite. Dolomitic marble is much more resistant to acid attack than calcite marble. The color of marble ranges from the brilliant white of calcite to black, including blue-gray, red, yellow and green, depending upon the mineral composition. TYPICAL USES Marble has many decorative and structural uses. It is used for outdoor sculpture as well as for sculpture bases; in architecture it is used in exterior walls and veneers, flooring, decorative features, stairways and walkways. The way in which the stone is used may be a factor in limiting or controlling the severity of exposure. The use or function of the marble may also affect the feasibility of applying certain treatments, but type of use is not the primary factor in the major types of deterioration and damage to which marble is susceptible.

[Michael of Stonehenge]

The restoration part of me says " Well we can try ", however if urea based materials found in plywood or wood tannins have been released then even a perfect poultice plan may not help in this circumstance.

You can try like hell but I have to be pessimistic on this one.

Michael

	Poultice This operation takes a minimum of twenty-four hours to extract foreign materials (stains) from most natural stones.

[Fred Hueston]

I agree with Michael..It it is wood tanins, it is going to be difficult. Might want to try a strong peroxide poultice.

	Poultice This operation takes a minimum of twenty-four hours to extract foreign materials (stains) from most natural stones.

[Huligar]

OK, with out seeing the images, I can not say what you should do, but if you have an insurance claim you should take full advantage and update your fire place rather than chancing the restoration.

[altheg]

I took a picture this morning but left my camera cable at home, but I will post it this weekend, please check back later.
I'm sure the stain is from wood, as the hearth is on a plywood subfloor.
Is there a link to a good poultice product or recipe somewhere ?
Alex

	Poultice This operation takes a minimum of twenty-four hours to extract foreign materials (stains) from most natural stones.

[StoneBuddy]

Not sure of poultice recipe for wood tannins. You Fred? I would say it will probably be a peroxide poultice or even something stronger. Anybody got a recommendation?

	Poultice This operation takes a minimum of twenty-four hours to extract foreign materials (stains) from most natural stones.

[Huligar]

Alex before we can tell you of a recipe, lets see if we can identify the staining agent. some of the chemicals can set the stain rather than remove it.

Alex where are you located, there may be a NSRA member that can stop by an assist you with this task.