A few weeks ago, Jim Hansel from CTS Rapid Set® came to Runyon and demoed two new products for us – Concrete Resurfacer and Skim Coat. Each of these cement-based materials has its benefits and specific uses. For detailed instructions on how and when to use each, keep reading.

How to Use Rapid Set® CR Concrete Resurfacer
To resurface damaged or discolored concrete, CR Concrete Resurfacer, an advanced hydraulic cement-based mortar, can be used both indoors and outdoors to produce a smooth, durable surface that’s ready for foot traffic in as little as three hours.

In about 30 minutes work time, a thin coat of CR Concrete Resurfacer – from 1/32 inch to ½ inch – can be applied to a dry surface that has a minimum temperature of 50°F. Clean the surface of oil, curing compound, dust, mastic or other bond breakers before application. The surface needs no priming. However, for porous substrates, use Rapid Set® Acrylic Primer to minimize pinholes.

Using a power mixer, combine CR Concrete Resurfacer with 2.5, but no more than 3, quarts of water per 25-lb bag. Using less water will achieve higher strengths. The mixed product should be used within 30 minutes at 70°F. CR Concrete Resurfacer uses Rapid Set’s self-curing technology, and can be left to air cure rather than wet curing under most conditions. However, in dry, windy or hot conditions, mist the area with water for a continuously wet surface for a proper cure.

One 25-lb bag yields approximately 0.22 cubic feet. Coverage at 1/8 inch is approximately 21.1 square feet. CR Concrete Resurfacer is formulated to match the light gray color of Portland cement.

How to Use Rapid Set® Skim Coat
To easily repair, level and smooth concrete substrates prior to floor covering installations or for floor underlayments, concrete repairs, patching and skim coating, Skim Coat, a hydraulic cement-based material, can be used both indoors and outdoors to produce a smooth, high-bond surface that’s resistant to mold and mildew. However, Skim Coat cannot be used on a worn surface and will not support car or forklift traffic.

In about 30 minutes work time at temperatures of 70°F, Skim Coat is applied in thicknesses from feather-edge up to 1-inch deep to a surface that’s been mechanically abraded by scarifying, grinding, shot-blasting or other approved methods. For a good bond, remove all loose particles, oil, bond breakers, paint, acids, dirt or other materials. Priming is necessary only on porous substrates where Skim Coat is applied in multiple lifts. Rapid Set® Acrylic Primer is specially formulated for this purpose.

Using a ½” drill mixer with a mixing paddle, combine Skim Coat with no more than 4 quarts of clean water per 20-lb bag. Do not add any additives or admixtures except one packet of Rapid Set® Set Control® retarding admixture to extend working time or one packet of Rapid Set® Flow Control® to increase the flow of the product. In about an hour, top with flooring such as VCT, sheet vinyl, carpet, tile or pavers. Epoxy coatings can be applied in 16 hours.
One 20-lb bag has skim coat coverage of 66.6 square feet at 1/8-inch deep or 33.4 square feet at ¼-inch deep. Skim Coat can be compatible with water based sealers.