Stone Care & Maintenance

STONE MAINTENANCE GUIDE & STAIN MANAGEMENT:

Stone Procurement proceeds through four stage:

1. Selection / Design by architect
2. Stone supplier fabricates & delivers the material.
3. Proper stone installation & protection.
4. Establishing stone maintenance cycle properly.

Stone Maintenance cycle:

(Designing Proper three steps stone maintenance programme)

There are three phases in stone maintenance cycle. These are;

a. Preventive Maintenance :

• Protecting the interior of stone with Penetrating SEALERS;
• Proper matting of entrance.

b. Daily Maintenance :

• Dusting & sweeping with Vacuum or Broom;
• Wet cleaning;
• Repairing of cracks & Joints with glues / chemicals;
• Powder or liquid polishing (if possible);
• Reabsorbing STAINS with POULTICE powders .
• Restoration:
• Resurfacing the stone with a diamond abrasive program to remove scratches and abrasions;
• Deep cleaning of pores of textured surface.

Preventive Maintenance :

SEALERS: Sealers are of two types;

• Coating
• Impregnators/ Penetrating sealers

Coatings : Coatings are sealers that place a sacrificial coating on the surface of the stone. This is a film that lies on the top of the stone acting as barrier to prevent water, oil or dirt from entering into pores of the stone. Coating sealers are usually acrylics, urethanes, epoxies and varnishes.

These are further categorised into two types; STRIPPABLES & PERMANENT

So, coating sealers are film-forming polymers, which are applied to floors to maintain physical barriers that isolate the stone surface from abrasions.

Advantages :

• Economical and easy to apply.

Disadvantages:

• Since most coatings are typically softer than the stone itself, they are usually scratched and scuff very easily & will show traffic patterns soon after application. So, reapplication after short intervals becomes necessary.
• Coatings give unnatural, wave like or plastic look on natural stones.
• Under UV light, this can turn yellow as time passes.
• Some wax strippers can harm certain stones.
• Moisture can be trapped below the stone. Thus coating can block breathing of natural stone.

Impregnator/ Penetrating Sealers : these are the microscopic balls of generally silicones, which attach themselves to the crevices inside the stone. These balls of silicones are negatively charged, which means they repel each other so that they are not clustered to become a big ball of silicone. Once attached they become permanent part of stone & give out a magnetic charge, which creates an invisible umbrella between balls. Thus balls becomes a shield when a much larger drop of liquid lands on them. This shield holds the liquid upside and prevents its penetration in the stone pores.

Advantages:

• Impregnators do not change the appearance of stone.
• Most impregnators don’t require frequent reapplication.
• No effects of UV, as the impregnators are below the stone surface.
• Some impregnators are hydrophobic or oilliophobic.
• Low maintenance cost.

Disadvantages:

• Initial cost is very high compared to coating.
• Solvent-based impregnators are highly inflammable during application.
• Solvent-based impregnator produce high VOC (Volatile organic compounds) so these smells bad & harmful to environment.

b. Daily Maintenance :

• Dusting & sweeping with Vacuum or Broom;
• Wet cleaning;
• Repairing of cracks & Joints with glues / chemicals;
• Powder or liquid polishing (if possible);
• Reabsorbing STAINS with POULTICE powders .

Cleaning chemicals:

• Soaps: Vegetable oil based soaps are best for natural stone cleaning. As they are user & environment friendly. The residues that soap tends to leave behind can be utilised as natural dressing, which acts as preventive stone management.
• Detergents: Detergents are water-soluble, so they are pH based & so should be used only after expert’s advice.
• Abrasives: Abrasive may be combined with soap or detergent. For scouring a surface, specially honed, abrasives remains thin layers from surface.
• Bleach: Bleaches are oxidising agents (generally oxygen) & are useful in stains removal.

c. Restoration:

• Resurfacing the stone with a diamond abrasive program to remove scratches and abrasions;
• Deep cleaning of pores of textured surface.

STAIN MANAGEMENT:

As we are talking about stain management; the first thing comes to mind is “Why stones are stained ?? The answer is stones are natural alkalis (Hydroxides i.e., OH) and so are dirt & soil. So, stones and dirt get attracted to each other, often making cleaning very difficult.

The other question, which arises in our mind, is “ Can we clean our natural stone floors with chemicals?” The answer is a strict NO. We should use these cleaners after an expert’s advice only. Natural stones should be treated carefully and gently.

First one should understand the Basic facts about stones and their classification. Secondly, one should understand the chemicals with which you should clean or treat your stone tops. Most stones used today are sensitive to both acidic and alkali cleaners. The reason is the composition of stones, as the stones are alkalies. Acidic chemicals burn them by dissolving the bonding agents that keep them together. Use of alkalic chemicals will deteriorate the stone gradually. So, Neutral cleaners having pH value near 7 are the best choice for cleaning stones. We will talk about it in details under the heading

STAIN MANAGEMENT.

STAIN REMOVAL:

To restore the glass & shine of stone surface an effective stain removal programme should be followed.

STAIN REMOVAL GUIDE:

Natural stones are generally porous materials. This porosity is the main reason of Stain on the surface of stones. Surprisingly, this very porosity helps in the removal of stains.

Understanding the Stain is important. As we know that everything in this world exist because of chemical reactions. (Existence of U & I is also because of some chemical reactions). Staining of stone is nothing but patch because of chemical reaction & reversal of this chemical reaction is removal of the stain. This is the basic concept of stain and stain removal. So, if a stone has absorbed a stain we have to reabsorb it into some other material. This different material is what we call as POULTICE. A poultice can be made with powdered whiting & hydrogen peroxide or a chemical reducing agent; depending on nature of stain.

TYPES OF STAINS:

Oil based Stains: Greece, tar, food stains & cooking oil.

Organic Stains: Fruit juices, tobacco, cosmetic, coffee & tea.

Ink Stain: Magic marker or Pen Ink.

Metal Stains: Iron (rusty), copper, bronze or Aluminium.

Biological Stains: Algae, Lichens etc.

THE PRIMARY STEPS OF STAIN REMOVAL (FIRST AID)

1. Identify the stain type.
2. Any spill should be cleaned as soon as possible. Bolt spill with paper towel or clean rag. At this stage it is important only to bolt (Pls take care: wiping should be avoided.).
3. Use only cold water & stone soap or a natural cleaner. Rinse the area several times. Most of the stains will disappear. If still present, stain will be removed by applying chemical Poultices.
4. Consult a stone restoration specialist or your stone supplier if in doubt or otherwise go ahead with Poultices.

Chemicals should be used to remove stains only as the last resort, as natural or soft environment friendly soap cleaning method is best suited for natural stone surface. Always perform a test in inconspicuous area first to determine the result of chemical cleaning.

Chemicals, which are used as stain removers, can be classified in three categories:

1. Solvents (No pH determination): e.g., Mineral spirits, Xylene or Chlorinated solvents. Solvents dissolve grease, chewing gum, lipstick etc.
2. Bleaches (Oxidants): e.g., Hydrogen Peroxide, Ammonia, and Acetic acid etc. Bleaches discolour stains.
3. Absorbents: e.g., blotting paper, Chalk, Powder telcom etc. These absorb fresh oil & grease stains.

POULTICE : As we have used this word so many times, its necessary to know; What is Poultice ???

As we know the stains are absorbed in the stone surface. Poultice is a material apart from chemicals, which is used to reabsorb stain from the stone surface.

Different Poultice materials are;

• Chalk (whiting, available easily in hardware shops)
• Methyl cellulose
• Talk
• Sepiolite (hydrous magnesium silicate)
• Diatomaceous Earth
• Clay (Fullers earth)

Applying the Poultice (final solution)

1. Clean the stained area with cold water & stone soap. Remember to bolt rather than wipe.
2. Prewet the stained area with a little water. Prewetting fills the pores of stone with water; so isolating the stain & accelerating the removal by the chemicals.
3. Prepare the poultice. If a powder is to be used, premix the powder & chemicals of choice into a thick paste. If a paper poultice is to be used, soak the paper into chemical. Lift the paper out of the chemical until it stops dripping.
4. Apply this paste only on the effected area & make a layer of about ¼ inch thick.
5. Allow the paste to sit for 12-24 hours after covering it with plastic sheet. Drying may take more time.
6. Remove poultice from the stain, rinse with distilled water & dry with clean rag.
7. If stain is not removed completely then repeat the same procedure again.

QUICK REFERENCE QUIDE FOR POULTICE FOR DIFFERENT STAINS;