Note: Primers and activators are adhesion promoters and not an alternative to improve poor preparation / cleaning of the joint surface. Primers also improve the long-term adhesion performance of the sealed joint. Other metals, such as copper, brass and titanium-zinc, also have to be cleaned and pre-treated using Sika® Aktivator-205,wiped on 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.

The substrate must be clean, dry, sound and homogeneous, free from oils, grease, dust and loose or friable particles. However, for optimum adhesion, joint durability and critical, high performance applications the following priming and/or pre-treatment procedures must be followed: All joints must be correctly designed and dimensioned in accordance with the relevant standards and codes of practice before their construction. The basis for calculation of the necessary joint widths are the type of structure, dimensions, technical values of the adjacent building materials, joint sealing material and the specific exposure of the building and the joints. CE Marking and Declaration of Performance to EN 15651-4 - Sealants for non-structural use in joints in buildings - Sealants for pedestrian walkways. Classification: PW EXT-INT CC 25 HM Consult the tank manufacturer's instructions for their specific preparation and priming recommendations.

Example of typical joint widths for joints between concrete elements for exterior applications if the joint sealant is classified as ±35 % movement capability according to ASTM C 719, Calculation according to ASTM C 1472-10: Joint distance [m] The joint dimensions must be designed to suit the movement capability of the sealant. The joint width must be ≥ 10 mm and ≤ 35 mm. A width to depth ratio of 2:1 for facade joints must be maintained (for exceptions, see table below). Removal techniques such as wire brushing, grinding, sanding or other suitable mechanical tools can be used.

However, for optimum adhesion and critical, high performance applications, such as on multi-story buildings, highly stressed joints, extreme weather exposure or water immersion, the following priming and/or pre-treatment procedures shall be followed: The substrate must be clean, dry, sound and homogeneous, free from oils, grease, dust and loose or friable particles. Sikaflex® PRO adheres without primers and/or activators. It is suitable for making elastic, vibration-resistant joint seals, Can also be used for a variety of interior and exterior sealing applicationsAll dust, loose and friable material must be completely removed from all surfaces before application of any activators, primers or sealant. Other metals, such as copper, brass and titanium-zinc: Clean and pre-treat using Sika® Aktivator-205 applied with a clean cloth. After a waiting time of > 15 minutes (< 6 hours), apply Sika® Primer-3 N applied by brush. Before sealing, allow a waiting time of > 30 minutes (< 8 hours) Removal techniques such as wire brushing, grinding, grit blasting or other suitable mechanical tools can be used. Other metals, such as copper, brass and titanium-zinc, clean and pre-treat using Sika® Cleaner P or Sika® Aktivator-205 applied with a clean cloth. After a waiting time of > 15 minutes (< 6 hours). Apply Sika® Primer-3 N by brush.

PVC has to be cleaned and pre-treated using Sika® Primer-215 applied with a brush. Before sealing, allow a waiting time of > 30 minutes (< 8 hours).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 drying time of > 15 minutes (< 2 hours). All dust, loose and friable material must be completely removed from all surfaces before application of any activators, primers or adhesive / sealant.