Weather-resistant STP adhesive and sealant with a broad adhesion spectrum
Sikaflex®-521 UV is a weather-resistant, one-component STP adhesive and sealant with good adhesion to a wide range of substrates such as metals, ABS, PC, FRP and wood where no special pre-treatment is usually required. This universal product is suitable for indoor and outdoor sealing.
- Resistant to ageing and weathering
- Good adhesion to a wide range of substrates without special pre-treatment
- Free from isocyanate and solvents
Product advantages
- Resistant to ageing and weathering
- Good adhesion to a wide range of substrates without special pre-treatment
- Free from isocyanate and solvents
- Can be painted over
- Sandable
- Low odour
ApplicationSikaflex®-521 UV adheres well to a variety of substrates and is suitable for permanent, elastic sealing and bonding. Suitable substrates, including wood, are metals, primers and paints (two-component systems), ceramic materials and plastics. This universal product is suitable for interior and exterior waterproofing. Follow the manufacturer's recommendations before using Sikaflex®-521 UV on materials susceptible to stress cracking. Preliminary tests must be carried out with original materials to avoid stress cracking. This product is only suitable for experienced users. To ensure adhesion and material compatibility, preliminary tests must be carried out with original materials under the respective conditions.
Technical data
Chemical base: Silane-terminated polymer (STP)
Colour (CQP001-1): black
Curing mechanism: Moisture curing
Density before curing: 1.4kg/litre
Stability: good
Processing temperature: 5 to 40°C
Skin forming time (CQP019-1): 30 minutes (23°C)
Volume change (CQP014-1): -2%
Shore A hardness (CQP023-1 / ISO 7619-1): 40
Tensile strength (CQP036-1 / ISO 527): 1.8 MPa
Elongation at break (CQP036-1 / ISO 527): 400%
Tear resistance (CQP045-1 / ISO 34): 5.5 N/mm
Shelf life (CQP016-1): 12 months when stored below 25°C
Safety instructions and warnings
Further information can be found in the linked media and download files.
Manufacturer contact information
Contact Manufacturer
Sika Germany GmbH
Kornwestheimer Str. 103-107
D-70439 Stuttgart
EHS@de.sika.com