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For cool room construction, refrigerated container components, and insulation panel installations, FulasealPro 840NS Sealant is a non-skinning, butyl-based sealant that creates a permanently plastic, moisture-resistant barrier. Formulated to remain wet and sticky inside concealed lap joints, it seals sandwich panels, Alucobond, and metal substrates without drying out, skinning, or cracking over time.
FulasealPro 840NS Sealant operates as a non-drying, permanently plastic sealant. Unlike standard elastomeric curing sealants, this butyl compound remains in a constant paste-like state, ensuring it does not skin or lose its tackiness inside closed assemblies. When clamped between sheet metal, Polystyrene, or Alucobond panels, the non-skinning formulation flows into small gaps to block air and moisture infiltration while resisting the growth of mould and mildew in damp or temperature-controlled environments. Because the chemistry is non-corrosive, it is safe for direct contact with sensitive metals like Zincalume, aluminium, and galvanised iron without the risk of chemical degradation or surface etching. It will not separate or bleed when applied to non-porous surfaces.
FulasealPro 840NS Sealant is formulated for small joints and concealed applications on the following substrates:
All surfaces must be clean, dry, sound, and free of dust, oil, old sealant, or other contaminants before application. Clean lightly contaminated surfaces using the two-rag wipe method with Isopropyl Alcohol (IPA) on a clean, lint-free cloth, ensuring the solvent does not dry directly on the substrate. For heavily contaminated surfaces, clean first with a generic wax and grease remover using the two-rag wipe method, followed by a final IPA clean.
Apply the sealant to one surface by holding the gun at a 45-degree angle and pushing the bead forward, then immediately combine the two surfaces. Uncured sealant can be cleaned up using an organic solvent such as mineral spirits.
Use FulasealPRO 840NS for small, static joints where no movement or dynamic stress is expected. It is a permanently plastic, non-elastomeric sealant designed for applications like cool room construction and insulation panels, not for joints that will move.
No, FulasealPRO 840NS is not suitable for applications exposed to weathering and dirt pick-up. For exposed areas, consider a product like H.B. Fuller 770 Sanitary Silicone, which is designed for those conditions.
FulasealPRO 840NS is formulated for a service temperature range of -40°C to +50°C. This makes it suitable for demanding low-temperature environments such as cool rooms and refrigeration units.
No, this sealant is not paintable. Ensure you account for this in your project planning, especially for visible joints.
| Application | Key benefit | Primary trades |
|---|---|---|
| Cool room construction and sealing | Forms a durable, non-skinning, permanently plastic seal that resists moisture and performs down to -40°C. | Cool room installers, refrigeration technicians |
| Refrigeration unit construction | Ensures excellent low-temperature performance and moisture resistance without separating or bleeding on non-porous surfaces. | Refrigeration manufacturers, appliance assemblers |
| Insulation panel construction | Provides a non-corrosive, non-sagging seal suitable for static joints in sandwich panels, Alucobond, and Zincalume. | Panel fabricators, builders |
| Concealed lap joint applications | Delivers a permanently plastic, non-skinning seal that maintains integrity over time, avoiding common failure modes of exposed sealants. | General builders, metal fabricators |
Clean all surfaces thoroughly following the two-rag IPA method. Ensure no dust, oil, or old sealant remains. Allow cleaned surfaces to fully dry before applying the mastic.
Cut the cartridge seal, attach the nozzle, and cut to the desired bead size (typically 5 mm). Load the cartridge into a quality caulking gun for smooth application.
Hold the gun at a 45° angle and push forward, forcing the sealant into the joint. Apply a continuous bead to one surface, then assemble the joint while the sealant is fresh. Adjust panels as required – the non-skinning property allows time to reposition.
Remove excess mastic immediately with a cloth dampened in mineral spirits. Dispose of waste safely according to local regulations.
For prolonged or repeated skin contact, use nitrile rubber gloves. Wear safety glasses to protect eyes. Respiratory protective equipment is not normally required unless ventilation is insufficient.
Ensure adequate ventilation during application. If ventilation is insufficient, wear suitable respiratory equipment.
Store between +5°C and +25°C in unopened packaging, in a dry area away from direct sunlight. Keep the container closed when not in use. Do not freeze. Dispose of solidified material in an approved landfill; consult local authorities for specific requirements.
Proper surface preparation is critical for FulasealPRO 840NS to achieve reliable adhesion and long-term performance.
Surface prep: All surfaces must be clean, dry, sound, and free of dust, oil, old sealant, or other contamination. For light contamination, use the 2-rag wipe method with Isopropyl Alcohol (IPA). For heavy contamination, use a generic wax and grease remover followed by a final IPA wipe. Light abrasion can further improve adhesion.
Primer: Not required for these common metals when properly prepared.
Surface prep: Ensure surfaces are clean, dry, and free from contaminants. Follow the 2-rag wipe method with IPA for general cleaning. If residues are present, use a wax and grease remover, then finish with an IPA wipe.
Primer: Not required.
Surface prep: Surfaces must be clean and dry. Consult plastic manufacturers for suitable cleaning solvents to avoid damage. Adhesion to specific plastics should always be pre-tested.
Primer: Pre-testing required to determine suitability and adhesion performance on specific plastic types.
| Property | Value |
|---|---|
| Colour | Off-White |
| Specific Gravity | ca. 1.4 |
| Application Temperature | +5°C to +35°C |
| Service Temperature | -40°C to +50°C |
| Skin Time | Non-skinning |
| Coverage | Approx. 15 lineal metres (5mm bead per cartridge) |
Here are some common examples on where H.B Fuller FulasealPro 840NS Sealant used by our customers.
