UV resistant assembly sealant

  1. Sikaflex-521 UV adheres well to a wide variety of substrates and is suitable for elastic sealing and bonding applications in transportation, wind and general industry, for bonding stiffeners in elevator industry and many more.
Available pack size 300ml, 600ml, 23Litre
Standards ISO, RoHS,REACH
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Chemical Composition Silane Terminated Polymer
Curing Mechanism Moisture
Color White/Grey/Black
Specific Gravity NA
Recommended substrates Metals, Plastics, Composites, Ceramic.
Max gap fill 6mm
Tack Free Time N/A
Elongation at Break 400% approx.
Hardness 40 Shore A
Tensile Strength 1.8MPa
Service Temperature -50 to +90 °C

Features and Benefits

Good Ageing and weathering resistant
Bonds well to a wide variety of substrates without the need for special pre-treatment
Can be over painted after it becomes tack free
Low odor, Isocyanate- and solvent-free, Silicone- and PVC-free


  • The product offers very good UV resistance suitable for outdoor application
  • Suitable substrate materials include timber, metals, metal primers and paint coatings (2-part systems), ceramic materials and plastics