Sikaflex 521 sealant grey

• Waterproofing pop rivets during roof mounting
• Sealing aluminium Z-profiles on van camper roofs (mechanically fastened with pop rivets)
• Elastic sealing of roof penetrations and connections (interior/exterior)

Tip: we use / include Sikaflex®-521 UV, among others (optional), with our Aluminium Z-profiles (set of 4), because an elastic seal handles the vibrations and movement of the roof better.

• Resistant to weather and ageing (suitable for outdoor use)
• Adheres to many surfaces without special pretreatment
• Permanently elastic – effectively absorbs movement and vibrations
• Isocyanate- and solvent-free
• Low odour and in many cases paintable (always test beforehand)

Note: surface preparation remains important. Always ensure a clean, dry, and grease-free surface.

Sikaflex®-521 UV is intended for sealing and light bonding/sealing applications, but not for structural bonding on a camper roof.

• Do not use for bonding plastic spoilers
• Do not use for bonding corner brackets
• Do not use as the sole means of fastening solar panels to the roof

Why not? With solar panels, the roof is constantly under stress (temperature, wind, vibrations). For safe, long-term roof mounting, a structural adhesive is required, along with the correct system setup (and often primers) — so you can let go and prevent damage.

• Surface: clean, dry, and grease-free
• Application temperature: approx. 5 °C to 40 °C
• Skin formation: approximately 30 minutes (depending on conditions)
• Curing: via humidity (this takes longer in cold/dry conditions)

Complete the work within the skin formation time and test adhesion/compatibility beforehand if in doubt.

Can I use this to bond solar panels?

No. For solar panels (spoilers/corner brackets), we recommend a suitable structural adhesive. Sikaflex®-521 UV is intended for sealing and elastic finishing.

Why do you include this sealant with Z-profiles?

Z-profiles are mechanically fastened with pop rivets. This sealant is ideal for waterproofing pop rivets and profiles, while keeping the assembly elastic.

Does it adhere to aluminium and common camper materials?

Yes, it adheres well to many surfaces (including metal, various plastics, and wood), often without primer. A clean surface and proper preparation remain crucial.

Unsure whether you need a sealant or a structural adhesive for your application? Contact us — this will help you avoid wrong choices and unsafe situations.

or WhatsApp: 06-38629787

Safety and application information: always follow the product information sheet and use a test area if in doubt.