Frequently Asked Questions

Is it necessary to seal a natural stone?

What is an impregnating Sealer?

What is the difference between sealing and impregnating?

Will an impregnator actually stain-proof a natural stone?

Do  sealers prevent oil penetration into natural stones?

So what does an impregnating sealer do?

What maintenance is still needed after sealing the stone?

 How often do you need to seal your natural stones?

Why do sealers wear so quickly in high traffic areas?

How do I know the sealer is still effective?

What difference will Micro MED’s sealers bring?

The Answers

                   Is it necessary to seal a natural stone?

To preserve a natural stone installation it is very important to protect it with a proper sealer. All natural stones are porous, even granite. As long as we have an absorption factor, stone will stain and deteriorate over time since the regular tap water used in maintenance contains salts, minerals and chlorine which are all harmful: just look at the Grand Canyon, Bryce Canyon or Zion and you will see how water has eroded the natural stones there. In addition more and more colorful marbles are being selected and used for their beauty and not their strength. These marbles are generally very prone to traffic abrasion and staining.

                       What is an impregnating Sealer?

Impregnator or penetrating sealers are designed to penetrate below the surface of the stone and either deposit solid particles in the pores of the stone, or coat the individual minerals below the surface. Penetrating sealers work by restricting water, oil and dirt from entering the stone or tile.
Properly applied, a good impregnator sealer will not affect the texture or the appearance of the stone. For all polished and smooth surfaces, an impregnator is recommended since sealers, which are surface coats, will not bond and will be easy abraded.

   What is the difference between sealing and impregnating?

In the stone industry, sealing and impregnating are often confused. The main objective of an impregnator is to protect the inside of natural stone from staining. Impregnators help prevent fluids from penetrating into the stone surface, but they do nothing to protect the top surface of the stone. They do not prevent traffic patterns, and they will not prevent etching from acid spills on marble. An impregnator will keep the acid out of the stone but not off the top surface.

 Will an impregnator actually stain-proof a natural stone?

No. Most penetrating sealers are designed to be either water or oil resistant, not water or oil proof If a liquid is left on the stone long enough, it will eventually penetrate and stain. Penetrating sealers are designed to give you time to clean up the spill before staining occurs. Nor are they designed to prevent acid etching that happens from lemon, vinegar, tomato and other acidic foods and drinks. Any acid will etch the surface of most marble and limestone, whether sealed or unsealed.

Do  sealers prevent oil penetration into natural stones?

Most sealers will prevent water and oil penetration, but it is very difficult to stop hot cooking oil from penetrating into the stone, because it can melt the resin in the stone.

              So what does an impregnating sealer do?

Impregnators are a mixture of silicon, resins, and usually a mineral spirit, which is a solvent. That is why they have a strong odor. The mineral spirit is added to the mixture because it acts as a carrier for the silicones and resins. The mineral spirit rides the resin and silicone into the stone as a liquid form. The mineral spirit evaporates out of the stone and leaves the silicone resin. The silicone and resin then begin to cure into a solid form, thus forming a fluid repellent membrane in the pores of the stone. This all happens within five to 10 minutes. However, complete curing time is usually 12 hours due to moisture content in natural stone.

 What maintenance is still needed after sealing the stone?

   Impregnators and sealers are preventive measures that provide extra protection to the stone which gives you time to clean up spills and such before they have the time to penetrate deeply and cause staining. Natural stone still needs to be maintained with proper stone care products after it has been sealed. Sealers will last longer and work better when the stone is properly maintained.

                How often do you need to seal your natural stones? 

Impregnating sealers will not last forever. Over time, the sealer loses its strength and bond to the stone and eventually wears and evaporates. Sealers lose their ability to protect through time and wear and tear. Some sealers are better than others are, and some will last longer. However in high traffic areas (shower, kitchen or dining room floors), the sealers will not last more than a year.

  Why do sealers wear so quickly in high traffic areas?

In a high traffic floor areas, the impregnator wears down as the stone surface wears down. The reason is because impregnators only penetrate approximately 1/6 inch (1.6 mm) or less. Since stones vary in their porosity, the sealer will penetrate more in some stones than in others. Additionally, some stones require one coat while others require two or more. But as the stone erodes, such as travertine, so goes the sealer. Sealers do not prevent the stone from abrasive traffic wear.

             How do I know the sealer is still effective?

A good way to measure the strength of an impregnating sealer is to apply water to the surface and to see if the stone darkens within a few minutes. If the stone darkens, this means that moisture has penetrated, and a fresh coat should be applied. It is important to remember that if the moisture does not bead up on the surface, it does not necessarily mean that the impregnator/sealer is not working: it might mean that it’s just working at a reduced level.