For your high-performance patching and detailing needs, use Rapid Set® WunderFixx® Concrete Patching Compound. WunderFixx® is a fast-setting, durable, one-component concrete patching material formulated with a premium-grade hydraulic cement, high-performance polymers and a finely ground aggregate. It is suitable for moist environments on interior and exterior projects, and ideal for patching and detailing on tilt-up panels, pre-cast concrete, concrete block and other concrete surfaces.

Mix WunderFixx® with water to produce a workable, easy-to-apply mixture with excellent bonding characteristics. Trowel WunderFixx® over existing concrete from featheredge to ½-inch thick to achieve a smooth, uniform concrete appearance. After applying, you may sand WunderFixx® to achieve an ultra-smooth finish. One 50-lb bag of WunderFixx® will cover 115 ft2 at 1/16”.


Rapid Set® WUNDERFIXX® is a high performance, gray concrete smoothing compound. WUNDERFIXX® is a blend of Rapid Set hydraulic cement, highperformance polymers, self-curing technology (SCT) and finely ground aggregate. Mix WUNDERFIXX® with water to produce a workable, easy-to-apply mixture with excellent bonding characteristics. Trowel apply WUNDERFIXX® to achieve a smooth and uniform finish. After applying, WUNDERFIXX® may be sanded within 24 hours to achieve an ultrasmooth finish.


Use WUNDERFIXX® for cosmetic patching, detailing and smoothing on tilt-up panels, precast, formed work, concrete block and other concrete and masonry surfaces. Durable in wet environments, it is suitable for both interior and exterior applications. WUNDERFIXX® may be used on vertical/overhead and non-wearing horizontal surfaces.


Apply WUNDERFIXX® in thicknesses from skim coat to 1/2" (1.3 cm). For thicker applications, use appropriate Rapid Set® repair products. Consult your CTS Cement Representative for more information and training.


Application surface must be clean, sound and free from any materials that may inhibit bond, such as oil, asphalt, curing compound, acid, dirt and loose debris. Apply WUNDERFIXX® to a surface that is dry or saturated with no standing water. A test area should be applied to determine suitability in the repair environment.


The use of a drill-mounted mixing paddle is recommended. Organize work so that personnel and equipment are in place before mixing. Use clean, potable water. WUNDERFIXX® may be mixed using 6 to 8 quarts (5.7 L to 7.6 L) per 50-lb (22.7- kg) bag. Use less water to achieve higher strengths. Do not exceed 8 quarts (7.6 L) of water per bag. For increased fluidity and workability, use Rapid Set® FLOW Control® plasticizing admixture from the Rapid Set® Concrete Pharmacy®. Place the desired quantity of mix water into the mixing container. While the mixer is running, add WUNDERFIXX®. Mix for the minimum amount of time required to achieve a lump-free, uniform consistency. Do not retemper.


At time of installation, the surface and ambient temperatures must be between 50°F to 90°F (10°C to 32°C). WUNDERFIXX® has a working time of 30 minutes at a temperature of 70°F (21°C). Once in place, as the material becomes stiff (typically within 10 to 20 minutes), use a trowel to shave or cut the excess material to the desired shape. Material can be sanded, primed and painted the same day


WUNDERFIXX® does not require water curing or curing compound under moderate conditions at 70°F (21°C). In dry, windy or hot conditions, mist with water to maintain a continuously wet surface until the product has achieved sufficient strength.


  • Easy To Use: Just add water, no admixtures needed
  • High Performance: Patch, sand and paint the same day
  • Ultra-Smooth Finish: Grit free and sandable within 24 hours
  • Excellent Bond: Bonds to concrete, brick, block, plaster and more
  • Self-Curing Technology (SCT): No water curing needed under normal conditions


ENVIRONMENTAL ADVANTAGES: Use WUNDERFIXX® to reduce your carbon footprint and lower your environmental impact. Production of Rapid Set cement emits far less CO2 than portland cement. Contact your representative for LEED values and environmental information.

USGBC and related logo is a trademark owned by the U.S. Green Building Council and is used by permission.


DO NOT BREATHE DUST. AVOID CONTACT WITH SKIN AND EYES. Use material in well-ventilated areas only. Exposure to cement dust may irritate eyes, nose, throat, and the upper respiratory system/lungs. Silica exposure by inhalation may result in the development of lung injuries and pulmonary diseases, including silicosis and lung cancer. Seek medical treatment if you experience difficulty breathing while using this product. The use of a NIOSH/MSHA-approved respirator (P-, N- or R-95) is recommended to minimize inhalation of cement dust. Eat and drink only in dust-free areas to avoid ingesting cement dust. Skin contact with dry material or wet mixtures may result in bodily injury ranging from moderate irritation and thickening/cracking of skin to severe skin damage from chemical burns. If irritation or burning occurs, seek medical treatment. Protect eyes with goggles or safety glasses with side shields. Cover skin with protective clothing. Use chemical resistant gloves and waterproof boots. In case of skin contact with cement dust, immediately wash off dust with soap and water to avoid skin damage. In case of skin contact with wet concrete, wash exposed skin areas with cold running water as soon as possible. In case of eye contact with cement dust, flush immediately and repeatedly with clean water, and consult a physician. If wet concrete splashes into eyes, rinse eyes with clean water for at least 15 minutes and go to the hospital for further treatment.