Mineral Coatings for Masonry
Cathedral Stone Products Inc. has developed their Potassium Silicate Coating (formerly MasonRE® Mineral Coating), afor use on all masonry (mineral surfaces), and over latex and acrylic coatings. Similar coatings have been in use in Europe for over 160 years and are now produced for the first time in North America. This coating technology combines the advantages of silicate/mineral and silicone coatings. Unlike latex and acrylic coatings, they form a molecular bond with the masonry substrate and the coatings are 92% vapor permeable.
- Specially formulated for masonry surfaces and over dispersion coating.
- 92% vapor permeable.
- Color fast.
- Retards corrosion.
- Fire retardant.
- Withstands extreme climate conditions.
- Water repellent.
Available in 1 or 5 gal. | MSDS | Data Sheet | Specification Guidelines
Potassium Silicate Coating should only be used by experienced users. This coating can be applied to any sound masonry or plaster surface. (Do not use on wood, plastic, or apply over oil or gloss coating.) The surface must be clean, solid, dry and free from efflorescence. The surface must be completely dry at the time of application. Potassium Silicate Coating is designed for vertical surfaces only. Horizontal surfaces, especially where water can pool, are not suitable for application. Cracks and spalls must be repaired and cured before coating. Cracks can be filled with Jahn M30 or M40 mortars. To ensure even penetration of the coating, make sure repairs have been made with repair materials that are compatible to the substrate. Temperature (ambient and substrate) must be at least 45° F (8° C) and below 90° F (32° C). Do not apply the Potassium Silicate Coating when precipitation is expected within 48 hours of application. Do not apply Potassium Silicate Coating when the temperature is expected to reach the dew point within 24 hours. Protect adjoining surfaces from splashes. Potassium Silicate Coating can only be removed while wet. Once Potassium Silicate Coating dries they CANNOT be removed.
When coating with dark colors, irregularly absorbing surfaces, or freshly poured concrete the substrate should first be treated with Cathedral Stone Green Etch S-309 (see Cathedral Stone Stripper Section for more information). The difference in substrate absorption can cause small color variations, which are more noticeable on darker colors. The S-309 will etch masonry to create similarly absorbing surfaces. Contact Henry Frerk Sons at 773-588-0800 for further questions on proper substrate preparation prior to coating.
Do not mix Potassium Silicate Coating with water. If Potassium Silicate Coating needs to be thinned out add Cathedral Stone Liquid Silicate until the desired consistency is reached. Mix Potassium Silicate Coating with a drill prior to use. When installing multiple units of coating, be sure to box-mix (Box-mixing is the blending of coating by pouring alternately between two containers.) This will help alleviate any minor color inconsistencies between batches.
Substrate absorption definition: The absorption must not be too high or too low for the coating to be applied correctly. Absorption can be tested by applying small amounts of water (drops) on the vertical surface to be coated. Normal absorption can be defined as the water absorbing into the substrate without beading on the surface. High absorption can be defined as water being absorbed so quickly that all traces of water seem to disappear rapidly. Low absorption can be defined as water laying or beading on the surface of the substrate (masonry must be etched in cases of low absorption).
Protect all areas not to be coated prior to application. Substrate must be completely dry before coating. Do not work when precipitation is expected within 48 hours of installation. The coating needs adequate time to bond to the substrate and moisture disrupts this curing process. Apply liberally and spread well, filling all pores and cracks. Work wet into wet. Potassium Silicate Coating should be applied with a short bristle brush. Brushing increases the absorption of the coating into the masonry, resulting in a longer lasting, more durable coating. Spraying and rolling the coating is possible. Allow the first coat of Potassium Silicate Coating to dry of at least 12 hours. Apply a second coat of Potassium Silicate Coating in the same fashion; work wet into wet.
- Make sure the substrate is completely dry and there is no expected dew.
- Protect coatings from all forms of moisture: rain, dew, snow, etc. for 48 hours.
- Temperature must be at least 45°F (8°C).
- Protect any surfaces not to be coated.
- Do not add water to Potassium Silicate Coating .
- Always work wet into wet.
Place tools immediately in clean water when pausing work (15-30 minutes or more). Clean tools with clean water immediately after finishing work. Dried Potassium Silicate Coating is insoluble in water. Potassium Silicate Coating can be removed from non-porous surfaces with clean water while still wet.
Coverage depends on the absorption and structure of the substrate. Determine coverage with a trial application.
Normally absorptive, smooth surfaces with two coats:
One unit of Potassium Silicate Coating (approx. 5.0 gallons) will cover approx. 1200 square feet for a single coat and approx.750 square feet when two coats are applied. Coverage rates will generally be higher with darker color coatings.
Eye protection should be worn during mixing to protect eyes from splashing. Avoid contact with skin and mucous membranes. Work in well ventilated areas.
Storage and Shelf Life
Store in a dry area, away from direct sunlight. Storage conditions should be in the range of 40° – 80° F with low to average humidity. Average shelf life is six months in original, unopened packaging.
Notice: The information contained herein is based on our own research and the research of others, and it is provided solely as a service to help users. It is believed to be accurate to the best of our knowledge. However, no guarantee of its accuracy can be made, and it is not intended to serve as the basis for determining this product’s suitability in any particular situation. For this reason, purchasers are responsible to make their own tests and assume all risks associated with using this product.