Sikalastic® GDC Primer

ASTM E96 - water vapor transmission
ASTM C794 / ASTM D903 - wet adhesion to concrete

2-component epoxy

24 months 

Store dry at 50–77 °F (10–25 °C). Protect from moisture.

69 lb/ft³ (1.1 kg/l)

96%

24 g/l
 

-40 to 158 °F (-40 to 70 °C)

Component A to Component B = 3 to 1 (by volume)

Condition material to 50–86 °F (10–30 °C) before using for ease of application.

41 °F (5 °C) min. / 95 °F (35 °C) max.

Surfaces may be damp but surfaces with condensation present should be avoided. Substrate temperatures should be 5°F (3°C) or more above the dew point before application. Avoid application during rising substrate temperatures to significantly reduce the chance of pin holes.

41 °F (5 °C) min. / 140°F (60°C) max.

Saturated surface dry concrete (damp) conditions are acceptible but physical moisture from condensation should be avoided.
Residual moisture up to 100 % R.H. or 25 lb/1,000 ft²/24 hr (11.4 kg/92.9 m²/24 hr).

Application to Damp Concrete: Sikalastic® GDC Primer can be applied to damp concrete as soon as surface water has dissipated after rainfall or other sources of water have ceased.

Application to Green Concrete: Sikalastic® GDC Primer can be applied to horizontal concrete surfaces 48 hours after concrete pour (or when concrete is walkable) and vertical surfaces 24 hours after forms are removed. 

Minimum time: cured.  Maximum time: 72 hours.

* When Sikalastic® GDC Primer is left on the substrate for more than 72 hours, scuff sand/deglaze the surface and solvent wipe before proceeding with second coat of primer. 

380–450 ft² (35.3–41.8 m²) per pail

MUST produce a monolithic, pinhole-free and continuous mirror-like film finish. The need for multiple coats is directly related to surface absorption and substrate roughness.

For all concrete (green, damp and dry):

• Substrate must be clean, sound and free from oils, grease, dust, laitance and loose or friable particles. Paint, laitance, and other poorly adhering contents must be mechanically removed
• Substrate must have an open textured surface to allow Sikalastic® GDC Primer to penetrate (i.e. blast cleaning and grinding are considered acceptable means to achieve the desired surface profile. Acid and chemical etching are not acceptable to achieve the desired surface profile)
• Concrete surfaces should have a Surface Profile (CSP) of 2 to 5
• Before overall installation begins, Sika® recommends the application of several small test patches to determine primer application requirements and acceptability of final product performance
• Adhesion in peel tests should result in > 8 lbs per linear inch (PLI)
• Minimum substrate compressive strength > 3000 psi. at the time Sikalastic® GDC Primer is applied
• On fiber reinforced concrete, fibers should be flamed off the surface prior to application of Sikalastic® GDC Primer as a moisture barrier

Additional clarification for green (under 28 days old) concrete:

• Substrate must have an open textured surface to allow Sikalastic® GDC Primer to penetrate.  If green concrete surfaces have Concrete Surface Profile (CSP) of 2 to 5, powerwashing the surface may be the only surface preparation method required to remove any concrete laitance 
• If the green concrete surfaces do not have a Concrete Surface Profile (CSP) of 2 to 5, reprofiling by blast cleaning and grinding are considered acceptable means to achieve the desired surface profile. Acid and chemical etching are not acceptable means to achieve the desired surface profile

Premix each component.  Add one full can of component B to one full can of component A then mix with an electric drill and mixing (Jiffy Mixer type) paddle at a low speed keeping the paddle in the product to reduce air entrainment (300–400 rpm). Using a paint stick or similar is not sufficient to mix the primer.  Mix for a minimum 3 minutes; continue mixing until a homogeneous mix has been achieved. During mixing, scrape sides of pail with paint stick or paddle to ensure all contents are thoroughly mixed together. Unmixed material will not cure properly when applied.

Apply Sikalastic® GDC Primer uniformly (in 2 directions 90°) to the substrate using a medium nap roller, ensuring that a continuous coat is achieved over the entire surface. Pour contents of pail onto the desired substrate for best working time. Attempting to work from the pail will reduce working time.

Application MUST produce a mirror like finish.

 

For applications requiring two coats, apply the first coat at 10 mils (160 ft²/gal) and allow to cure.  Then, apply the second coat at 15 mils (100 ft²/gal) in accordance with the open time and application time windows.

Clean all tools and application equipment with cleaning solvent (Xylene, Acetone, are effective). Hardened/cured material can only be removed mechanically.