The substrate must be sound, clean, dry and free of all contaminants such as dirt, oil, grease, cement laitance, old sealants and poorly bonded paint coatings which could affect adhesion of the adhesive / sealant. The substrate must be of sufficient strength to manage
with the stresses induced by the sealant during movement.
Removal techniques such as wire brushing, grinding, sanding or other suitable mechanical tools can be used.
All dust, loose and friable material must be completely removed from all surfaces before application of any activators, primers or adhesive / sealant. For optimum adhesion, joint durability and critical, high performance applications the following priming and/or pre-treatment procedures must be followed:
Non-porous substrates
Aluminium, anodised aluminium, stainless steel, galvanised steel, powder coated metals or glazed tiles, slightly roughen surface with a fine abrasive pad. Clean and pre-treat using Sika® Aktivator-205 applied with a clean cloth. Before bonding / sealing, allow a waiting time of > 15
minutes (< 6 hours).
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. Allow a further waiting time of > 30 minutes (< 8 hours) before bonding / sealing.
PVC has to be cleaned and pre-treated using Sika® MultiPrimer Marine applied with a brush. Allow a waiting time of > 15 minutes (< 8 hours) before bonding / sealing.
Porous substrates
Concrete, aerated concrete and cement based renders, mortars and bricks, prime surface using Sika® Primer-3 N applied by brush.
Before bonding / sealing, allow a waiting time of > 30 minutes (< 8 hours).
For more detailed advice and instructions contact Sika Technical Services.
Note: Primers are adhesion promoters and not an alternative
to improve poor preparation / cleaning of
joint surfaces. Primers also improve the long term adhesion
performance of a sealed joint.
