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Moeller Stone Care has been cleaning, protecting, and caring for natural stone, ceramic and artificial stone for over 40 years. Our aim is to provide consistent, high-quality products, as well as acting as a support partner for specialist companies in their stone treatment.




Moeller Stone Care HMK S731 is for all absorbent natural and artificial stones. Reduces water and dirt penetration and potential frost damage. Interior and exterior use.

HMK® S731 is a ready-to-use silane-based impregnator that reduces the penetration of water and dirt into all natural stone surfaces (soft and hard stones), concrete, and unglazed bricks. HMK® S731 is vapor permeable, suitable for interior and exterior use, and will leave little to no aesthetic change on the surface.

Important: Clean the surface thoroughly before treatment using HMK® R155 Intensive Cleaner (diluted) followed by a flood rinse with water and allow at least 24 hours to dry (max residual moisture of 6-8%) before sealing. If underfloor heating exists, switch it off and allow the surface to cool to room temperature.


Instructions: Apply to chemically clean and dry surface with a natural bristle brush, or HMK® Z950-HMK Z951 sealing brushes. One or two thin and even applications wet on wet are usually sufficient. Allow 20 minutes between each application for penetration. Repeat the process for more absorbent surfaces. Thoroughly remove excess product 5-10 minutes after the last application with a white terry cloth; add solvent if necessary to facilitate the excess removal. Do not allow HMK® S731 to dry on the surface as it will be very difficult to remove once dried. It is possible to use HMK® S731 in an airless sprayer for use on vertical surfaces.


Do not walk on the treated area until it has dried completely. Protect the surface from rain and humidity for three days after treatment is applied. Do not apply to rubber, plastics, varnished surfaces, and solvent-intolerant surfaces. For regular cleaning and continued protection use HMK® P324 Liquid Stone Soap, a no-rinse natural product.


Coverage: About 35 to 110 square feet per liter


Warning: Chemical product. Contains Turpentine Substitute. Flammable. Keep away from heat, sparks, and flame. Harmful or fatal if swallowed or inhaled. Ensure the area to be treated is adequately ventilated. Avoid eye/skin contact. If exposed wash/flush with water and seek medical attention immediately. Keep out of the reach of children. See Material Safety Data Sheet for more detailed information. Do not use the product in temperatures below 50 and above 80°F.


Storage: Store in cool place and keep lid tightly closed.


Testing: Always test the product in an inconspicuous area to evaluate suitability, coverage and performance.


Limitation of liability: The liability of HMK® Moeller Stone Care and/or HMK Stone Care, Inc for defective products and any claims for damages whatsoever is limited to the purchase price of the products. HMK® Moeller Stone Care and/or HMK Stone Care, Inc shall not be liable for any consequential damages. No other warranty or representation is made or implied.

HMK® S731 Silane Impregnator

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