Inadequate surface preparation
Note: Primers are adhesion promoters and not an alternative to improve poor preparation or cleaning of the joint surface. Primers also improve the long term adhesion performance of the sealed joint.
Substrate testing
Note: Adhesion tests on project specific substrates must be performed and procedures agreed with all parties before full project application. For more detailed advice and instructions contact Sika Technical Services.
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 cope with the stresses induced by the sealant during movement.
- Use techniques such as wire brushing, grinding, grit blasting or other suitable mechanical tools to remove all weak substrate material.
- Repair all damaged joint edges with suitable Sika repair products.
- Remove all dust, loose and friable material from all surfaces before application of the sealant.
If tested or supported by experience, the Product can be used without primers or activators on many substrates.
NON-POROUS SUBSTRATES
Aluminium, anodised aluminium, stainless steel, galvanised steel, powder coated metals, glazed tiles, or other metals, such as copper, brass and titanium-zinc.
- Lightly roughen the surface with a fine abrasive pad.
- Clean and pre-treat using Sika® Aktivator-205 with a clean cloth. Wait until the flash off time has been achieved.
- Apply Sika® Primer-3 N by brush.
PVC substrates.
- Lightly roughen the surface with a fine abrasive pad.
- Clean and pre-treat using Sika® Aktivator-205 with a clean cloth. Wait until the flash off time has been achieved.
- Clean and pre-treat using Sika® Primer-215 applied with a brush.
Glass substrates
- Clean and pre-treat using Sika® Cleaner P applied with a clean cloth and wait until the flash off time has been achieved.
POROUS SUBSTRATES
Concrete, aerated concrete and cement based renders, mortars and bricks.
- Prime surface using Sika® Primer-3 N applied by brush.
For more details of the primer or pre-treatment products refer to the individual Product Data Sheet. Contact Sika Technical Services for additional information.