SpecChem > Products > Repair Mortars > SpecPrep SB

SpecPrep SB

Structural concrete bonding agent/anti-corrosion reinforcement coating

SpecPrep SB is a three-component, long open time, cement/epoxy bonding adhesive and anti-corrosion rebar coating. It offers a 24-hour open time and provides a structural bond for fresh concrete or repair mortars to existing concrete. Additionally, it serves as an anti-corrosion protective coating for steel rebar in concrete restoration, effectively resisting water and chloride penetration without forming a vapor barrier after curing.

  • Provides a long open time up to 24 hours for flexible application.
  • Bonds fresh concrete to hardened concrete and bonds steel to fresh concrete.
  • Suitable for use both interior and exterior, above or below grade.
  • Provides an anti-corrosion coating for steel reinforcement.
  • VOC compliant and solvent-free.

Tech Sheet
Safety Sheet
Sell Sheet


Surface Preparation:

  • Ensure surfaces are clean and structurally sound.
  • Remove all oil, grease, dirt, laitance, rust, and curing compounds.
  • Abrasive blast cleaning and mechanical removal methods are recommended to achieve a Concrete Surface Profile (CSP) of CSP 5-7 per ICRI Guideline # 310.2-1997.

Mixing Instructions:

  • Ready to use; do not thin with solvents.
  • Condition materials to a minimum of 60°F before use.
  • Mix 1 part of Part A with 1 part of Part B for 1 minute using a low-speed drill with a Jiffy mixer or paddle.
  • Slowly add the pre-measured Part C to achieve a smooth, lump-free consistency over 3 minutes.
  • Mix only what can be applied within the pot life.


  • Apply SpecPrep SB to the saturated surface damp (SSD) substrate using a stiff brush or hopper gun.
  • For bonding, apply at a rate of 65-75 sq ft per gallon to a minimum thickness of 20 mils.
  • The material can act as an effective bonding agent for up to 24 hours at approximately 65°F.


Available in 1-gallon units and 3.75-gallon units.

Test Data

  • Compressive Strength (ASTM C109): 3 days: 3,200 psi; 7 days: 6,200 psi; 28 days: 8,250 psi.
  • Flexural Strength (ASTM C348): 28 days: 1,285 psi.
  • Bond Strength (ASTM C882): 7 days with 1-hour open time: 2,490 psi; 24-hour open time: 2,550 psi.