Rapid Set® WunderFixx®:  Concrete Patching Compound

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”.



The Datasheet explains the performance and technical characteristics of Rapid Set® WunderFixx®.  It also shows how to use WunderFixx (i.e. surface preparation, mixing, placement and curing).

The Spanish Datasheet is also available here.


The Safety Data Sheet (SDS) outlines information and procedures for handling and working with Rapid Set® WunderFixx®.  It includes physical and chemical property information, potential hazards, emergency procedures and CTS’s contact information.


The Specification gives a detailed statement explaining the type of jobs to specify Rapid Set® WunderFixx® for, the scope of work, thicknesses, performance requirements and usage.

Click here for word document

Standard Practices

 Q: Where can I use WunderFixx®?
A: WunderFixx® can be used on tilt-ups, pre-cast, or cast-in-place concrete surfaces. WunderFixx is an ideal repair material for smoothing rough surfaces, seams, stable hairline cracks, bugholes, and imperfections in the concrete surface.

Q: Is WunderFixx sandable?
A: Yes, at normal temperatures, WunderFixx can be sanded after about 2 hours. It is easiest to sand within the first 24 hours.

Q: How should the surface be prepared?
A: Make sure all loose particles are removed from the surface to be patched. Make sure the repair surface is not contaminated by oil, bond breakers, paint, acids, dirt or other materials that will prevent a good bond.

Q: How much working time do I have with WunderFixx?
A: At normal temperatures, the working time of WunderFixx is approximately 60 minutes. Cold water and material will slow down the set time, and warm water and material will speed up the set time.

Q: What color is WunderFixx?
A: WunderFixx dries to a light grey color that matches most portland cement concrete.

Q: What coverage can I expect from a 50-lb. bag of WunderFixx?
A: Each 50-lb. bag of WunderFixx will cover an area of 90 square feet at 1/32 inch deep (skimcoat).

Q: Is WunderFixx waterproof?
A: WunderFixx is a weatherproof outdoor repair material and will stand up to moist conditions.  However, WunderFixx will not create a waterproof barrier.

Q: Can I use WunderFixx on floors and high traffic areas?
A: WunderFixx is designed as a cosmetic patching material. Due to the fact that WunderFixx is sandable, it will wear when left exposed to traffic. However, WunderFixx can be used on horizontal surfaces with moderate foot traffic if it is painted or coated, or covered with tile or flooring.

Q: How thick can I apply WunderFixx?
A: WunderFixx can be applied in thicknesses from featheredge up to ½-inch deep.

Q: How soon can I paint or coat WunderFixx?
A: Under dry conditions, water based coatings such as latex paint can be applied in 6 hours. Solvent based and impermeable coatings such as oil based paint and epoxy can be applied in 16 hours. Experience has shown that some coatings can be applied in much less time. Follow the coating manufacturer’s recommendations for surface condition.

Jobs & Applications

  • SkechersDistributionCenter in Rancho Belago, CA, Inland Concrete Constructors (concrete smoothing of panels)
  • MattelDistributionCenter in San Bernardino, CA, Oltmans Construction Company and JDC (concrete smoothing of walls)
  • Apffels Coffee Warehouse in Santa Fe Springs, CA (flawless walls and sharp edges and corners)
  • Victoria Gardens Parking Structure in Rancho Cucamonga, CA, McCarthy Construction (concrete smoothing of walls)
  • The PromenadeShopping Center in D’Iberville, MS, Foundation Contractors, Inc. (smoothed wall panels and slab)
  • MagnoliaShadowSchool, Shreveport, LA, Samuel Express Tilt Patch (concrete smoothing of walls)
  • Multi-purpose building Cvista, in Riverview, FL, Samuel Express Tilt Patch (concrete smoothing of walls)
  • Longhorn Village Retirement Community in Austin, TX, Manhattan Construction & Fees Associates (concrete smoothing of walls)
  • BuzzOatsBuilding in Phoenix, AZ (concrete smoothing of walls)
  • O’Connor Residence in Anaheim Hills, CA,
Leed Product Evaluation

TechnicalSupportWhether you’re working on a time-sensitive project and need answers, or evaluating and choosing the right cement products, or looking to achieve specific results, we are here to help. Get answers to your questions from our technical support team. Find and download useful information from our website. Ask us to help get your construction team up to speed by requesting a jobsite demonstration or educational seminars.

ConcreteCalculatorLearn how Rapid Set’s strength, speed and sustainability help you get better results and finish your jobs sooner. These Charts will show you how.

ProductEvaluationLEED product evaluations summarize a product’s ability to contribute to a variety of LEED credits. These credits include Solar Reflectivity (SS7), Regional Materials (MR4), Recycled Content (MR5), VOC Content (EQ4) and Innovation in Design (ID1).

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