Overview

DOWSIL™ 798 Cold and Clean Room Sealant is a specialised, high-performance silicone sealant designed for sealing joints in refrigeration units, cold rooms, and other areas prone to mildew and bacterial growth. With its one-part, neutral curing formulation, it provides a durable, flexible seal that resists mildew, bacteria, and other contaminants. Suitable for both interior and exterior use, DOWSIL™ 798 offers excellent adhesion to a wide range of substrates, including masonry, tiles, aluminium, PVCu, glass, and stainless steel. Its low modulus and high elasticity make it ideal for environments exposed to temperature extremes, UV radiation, and ozone.

• Bacteria and mildew resistant
• Superior performance under extreme conditions.
• Adheres to a wide range of materials

Preparation

Before applying sealant, make sure all surfaces to be sealed are clean, dry, and in good condition. Surfaces should be free from frost, release agents, old sealants, and any other contaminants that could affect adhesion.

• For non-porous surfaces, wipe them with a clean, oil- and lint-free cloth dampened with a suitable solvent such as DOWSIL™ R-40 Universal Cleaner to remove dirt, grease, and other contaminants.
• For porous surfaces like concrete, brickwork, and mortar, mechanically clean the surfaces using a steel brush, sanding disc, or another suitable mechanical method to remove debris and contaminants.
• To avoid contamination of the surrounding areas and ensure a neat sealant line, mask areas adjacent to the joints with tape. This will help prevent the sealant from touching unwanted surfaces.

Always ensure adequate ventilation when using solvents. Keep away from heat, sparks, and open flames. Wear solvent-resistant gloves and follow all safety precautions listed on the solvent container label.

Application

The sealant is ready for immediate use. Cut the tip off the cartridge and screw on the nozzle and cut the nozzle to the desired bead size. We recommend using the Geocel Cox Skeleton Gun for application.

• To avoid contamination of the surrounding areas and ensure a neat sealant line, mask areas adjacent to the joints with tape. This will help prevent the sealant from touching unwanted surfaces.
• When back-up material is necessary, use a closed-cell polyethylene backer rod. This helps prevent three-sided adhesion, ensuring proper sealant movement.
• For joints that are too shallow to accommodate a backer rod, use low tack polyethylene tape as a back-up material to provide back pressure.
• Apply the sealant to the prepared joint, ensuring it fills the joint completely. Be mindful of joint dimensions and depth to accommodate the sealant’s movement capabilities.
• Tool the sealant within 5 minutes of application to ensure good contact between the sealant and the substrate we recommend Bedec Silicone Profilers. Tooling also helps create a smooth, professional finish for the joint.

Always follow the instrutions found on the cartridge.

Aftercare & Storage