Overview

HB42 Fusion Ultimate Sealant is a next-generation hybrid polymer sealant, engineered to fuse the smooth toolability and clean finish of a traditional silicone with the superior strength, flexibility and long-term durability of a modern polymer. The result is a single, versatile sealant that performs where ordinary silicones and acrylics fall short.

Suitable across sanitary, construction, roofing, façade, automotive and marine applications, HB42 Fusion is also safe for use in food preparation areas and on consistently moist surfaces. It's the ideal choice for expansion and construction joints, and for sealing around plastic, timber and metal frames, thanks to excellent anti-mould and UV resistance built to last outdoors and indoors alike.

• Hybrid polymer technology - silicone-like finish, polymer-grade strength
• High movement accommodation - withstands ±20% joint movement without cracking
• Anti-mould & UV resistant - stays cleaner for longer, indoors and outdoors
• Overpaintable - compatible with waterbased paints once cured
• Wide temperature tolerance - service range of -40°C to +100°C
• Multi-surface adhesion - bonds to plastic, timber, metal and more
• Long-lasting - 20+ years life expectancy when applied correctly

Preparation

• Ensure all surfaces are clean, dry and free from dust, grease, oil or standing water.
• Clean non-porous surfaces (e.g. aluminium) appropriately with a suitable solvent cleaner.
• Prime porous substrates if required - check compatibility on a test area first.
• Check joint dimensions: minimum 6mm x 6mm, maximum 20mm wide x 12mm deep.
• For deeper joints, insert a backer rod before application to control sealant depth and improve movement performance.
• Mask joint edges with tape for a clean, professional finish if desired.

Application

• Cut the cartridge nozzle to the desired bead size and load into a standard cartridge gun.
• Apply the sealant firmly and evenly into the joint, keeping the gun at a consistent angle.
• Tool the sealant within 10 minutes of application for the best finish (a smoothing tool or spatula dipped in soapy water works well).
• Remove masking tape immediately after tooling, before the surface skins over.
• Allow to skin for approximately 15–20 minutes (at 23°C / 50% RH) before disturbing the surface.
• If overpainting, use waterbased paints only, and allow the sealant to fully cure first.

Tip: Work in temperatures between +5°C and +35°C for optimal application and curing performance.

Aftercare & Storage

Aftercare & Curing

• Keep the joint free from movement, water contact and dust while curing.
• Cure rate is approximately 3mm per 24 hours - larger beads will take longer to fully cure through.
• Avoid submerging the sealed joint in water; HB42 Fusion is not designed for permanently submerged or aquarium use.
• Once fully cured, the sealant offers excellent long-term resistance to mould growth and UV exposure.

Clean Up

• Wipe away excess uncured sealant immediately with a dry cloth or paper towel.
• Use a suitable solvent (such as isopropyl alcohol) to remove uncured residue from tools and non-porous surfaces.
• Cured sealant can only be removed mechanically (e.g. scraping) - solvents will not dissolve it once fully vulcanised.
• Clean the cartridge nozzle and reseal or replace it for future use to prevent the tube curing in storage.

Storage

Store unopened cartridges in cool, dry conditions between 5°C and 25°C. Under these conditions, shelf life is 12 months. Keep away from direct sunlight and frost during storage and transport (frost resistance during transport is rated to -15°C).