Poor adhesion due to incorrect priming procedure
Incorrectly defined or uncontrolled priming procedures may lead to a variation in Product performance.
Test adhesion on project-specific substrates and agree on procedures with all parties before full project application. For more information contact Sika Technical Services.
Poor adhesion due to inadequate surface preparation
Note: Primers are adhesion promoters. Primers cannot replace proper surface preparation and surface cleaning.
Do not use primers for improving poorly prepared or poorly cleaned joint surfaces.
The substrate must be sound, clean, dry and free of contaminants such as dirt, oil, grease, cement laitance, sealant residues and poorly bonded coatings which could affect adhesion of the primer and sealant.
The substrate must be of sufficient strength to withstand the stress induced by the sealant during movement.
Use techniques such as wire brushing, grinding, grit blasting or other suitable mechanical methods to remove all weak substrate material.
Repair all damaged joint edges with suitable Sika repair products.
Remove dust, loose and friable material from all surfaces before applying the sealant.
Use the following priming or pre-treatment procedures to ensure optimum adhesion and joint durability, or if the Product is used for high-performance applications such as joints on multi-storey buildings, highly stressed joints, or joints exposed to extreme weather.
