The substrate must be clean, dry, sound and homogeneous, free from oils, grease, dust and loose or friable particles. Cement laitance must be removed. Grinding the surface of non-porous substrates with a very fine abrasive pad may improve the adhesion performance of Sikaflex® Tank N.
The Sikaflex® Tank N joint sealing system is approved for application on uncoated liquid proofed precast concrete elements. Sikaflex® Tank N has a technical approval for use in storage / filling / handling facilities for water-polluting liquids or grade ≥ C35/C45 ≤ C50/60 (EN 206-1), in-situ concrete to DIN 1045 as “FD” (liquid proof) concrete, or “FDE” (penetration-tested liquid-proof) concrete.
Non- porous substrates
Aluminium, anodised aluminium, stainless steel, galvanised steel, powder coated metals or glazed tiles have to be cleaned and pre-treated using Sika® Aktivator-100, wiped on and off with a clean towel. Before sealing, allow a flash-off time of > 30 minutes (< 2 hours).
Other metals, such as copper, brass and titanium-zinc, also have to be cleaned and pre-treated using Sika® Aktivator-100,wiped on and off with a clean towel. After the necessary flash-off time, use a brush to apply Sika® Primer-3 N and allow a further flash-off time of > 30 minutes (< 8 hours) before sealing the joints.
PVC has to be cleaned and pre-treated using Sika® Primer-215 applied with a brush. Before sealing, allow a flash-off time of > 30 minutes (< 8 hours).
Porous substrates
Concrete, aerated concrete and cement-based renders, mortars, and brick have to be primed with Sika® Primer-215, for uses in accordance with ETA-09/0272, or Sika® Primer-3 N applied with a clean brush or roller. Before sealing allow a flash-off time of > 30 minutes (< 8 hours).
For more detailed advice and instructions please contact the local Sika Technical Services Department.
Note: Primers are adhesion promoters. They are neither a substitute for the correct cleaning of a surface, nor do they improve the strength of the surface significantly.