Seal-it® 520 PRIMER

Seal-it® 520 PRIMER is a high-quality, extra-durable adhesive primer for sealants and adhesives that is specially developed for porous surfaces/materials and that moisture-cures into a durable membrane.


  • Specially developed as a durable adhesion promoter for porous surfaces, such as masonry, stucco, cellular and aerated concrete, natural stone, sand-lime brick, untreated wood, gypsum blocks and other absorbent materials.
  • As a waterproof and moisture-proof primer for lasting protection of surfaces from moisture and water loads, to guarantee a strong and lasting bond/adhesion.
  • Completely seal porous surfaces off from surface absorption.
  • Can be used with sealants and adhesives based on silicone, hybrid polymer and MS-polymer® and polyurethane.


  • Forms a highly durable, non-porous membrane to protect from moisture and water loads.
  • Stops surface absorption and ensures excellent bonding.
  • Secures hard-to-remove dust particles to the bonding surface.
  • Easy to apply with a brush or roller.
  • Fast-drying, ready-made 1-part primer that retains its transparency.
  • Excellent resistance to UV, weather, water, moisture and ageing.
  • UN-approved packaging, fitted with safety seal.

Application conditions

  • Application temperature (ambient and surface) between +5°C and +35°C.
  • Before use, shake and/or mix Seal-it® 520 PRIMER well so it does not form a homogeneous mass.
  • Use a hard brush to remove any loose particles from bonding surfaces or other surfaces before applying Seal-it® 520 PRIMER.
  • Bonding surfaces and other surfaces must be dry, clean, uncontaminated, grease-free, dust-free, compatible and stable.
  • First use Seal-it® 510 CLEANER to degrease/clean greasy or contaminated surfaces properly before applying Seal-it® 520 PRIMER.
  • Use a suitable brush or roller to apply Seal-it® 520 PRIMER evenly and not too thickly.
  • If the sealant is not applied within the maximum drying time, you must sand off the old coat of primer and then reprime.
  • After use, close the canister as quickly as possible, so the Seal-it® 520 PRIMER does not harden.

Standard product line


250ml can

1000ml can




SI-XXX-XXXX-XXX = Article number.
Other colours and/or packaging on request.


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