Sikaflex-522 black 600 ml foil pack (unipack) - STP sealant for motorhome roof, windows and hatches

Sikaflex-522 is a one-component adhesive sealant based on STP (silane terminated polymer) that cures with the moisture in the air. On motorhomes and caravans it is used for sealing and elastic bonding both outside, for example on the roof, window frames and service hatches, and inside, in the kitchen and bathroom. This version is a black foil pack (unipack) holding 600 ml, twice as much as a standard 300 ml cartridge. That is handy for bigger jobs, such as renewing the seals on a whole roof or on several windows in one go. The sealant has high resistance to ageing, weathering and mould, keeps its colour in the sun and has very low emissions and odour, so it also works well inside the vehicle.

Key features

• one-component STP adhesive sealant, cures with air moisture
• 600 ml foil pack (unipack), black
• high resistance to ageing, weathering and UV
• contains a fungicide, resists mould
• free of isocyanate, solvents, phthalates and silicone
• bonds well to many substrates without special pre-treatment
• EC1 PLUS certificate (very low emissions)

Where to use it on a motorhome

• sealing the roof from outside, for example around roof penetrations, trims and roof-mounted parts
• window frames and roof lights
• service hatches and locker doors
• joints in the kitchen and bathroom, including areas exposed to moisture
• elastic bonding of lighter interior fittings
• ventilation and air-conditioning systems (meets the hygiene requirements of VDI 6022, sheet 1)

Substrates

Sikaflex-522 bonds well to timber, glass, metals, primed metals, 2-part paint coatings, ceramic materials and plastics. Many of them need no special pre-treatment. On plastics prone to stress cracking, such as some acrylic and polycarbonate glazing, test first on a piece of the same material. The manufacturer recommends an adhesion test on the original substrate before every new application.

Surface preparation

• Remove the old sealant and loose residue, ideally with a plastic scraper so you do not scratch the surface.
• The surface must be clean, dry and free of grease, oil and dust.
• Degrease the bonding area with a suitable cleaner and let it evaporate.
• On more demanding substrates use an activator such as Sika Activator-205, following the manufacturer's pre-treatment chart.
• Masking tape along the joint gives you clean, straight edges.

Applying from the foil pack

• Apply the 600 ml foil pack with a foil pack gun: manual, pneumatic or electric.
• The best temperature for the substrate and the sealant is 15-25 °C, and it can be applied from 5 to 40 °C.
• The sealant gets thicker in the cold, so keep the pack at room temperature before use.
• Tool the joint within about 30 minutes, before a skin forms. The manufacturer recommends Sika Tooling Agent N for this.
• In hot and humid weather the skin forms faster, so work in shorter sections.
• The sealant cures from the surface inwards, more slowly in cold and dry air.

Painting, cleaning and storage

The joint is best painted before a skin forms. If you paint later, wiping the joint with Sika Aktivator-100 or Activator-205 improves paint adhesion. Paints are usually less elastic than the sealant, so the paint may crack around the joint, which is why you should always do a test first. Uncured sealant can be removed from tools with Sika Remover-208, cured sealant only mechanically. Clean your hands straight away with hand cleaning wipes or an industrial hand cleaner and water, never with solvents. Keep the unopened pack below 25 °C and it stays usable for 12 months.

Safety

The product is labelled with the signal word "Warning" and the statements H317 (may cause an allergic skin reaction), H412 (harmful to aquatic life with long lasting effects) and EUH211. Wear gloves, keep the area ventilated and follow the safety data sheet. The manufacturer intends the product for experienced users.

Related products

• Sikaflex-522 white 600 ml - foil pack for bigger jobs
• Sikaflex-522 black 300 ml - cartridge for a standard gun
• Sikaflex-522 white 100 ml - small tube for minor repairs
• Sika Activator-205 30 ml - surface preparation before sealing
• Sika Remover-208 Spray - removes uncured sealant from tools
• Sika Tooling Agent N 1 l - for smoothing joints

Technical data

Manufacturer

Sika AG, Zugerstrasse 50, 6340 Baar, Switzerland.