Selleys 100mL Autofix Instant Gasket Black | RTV Silicone | Australia

Conventional cork gaskets compress, harden, and fail over time — especially in high-temperature, high-pressure engine environments where they’re subjected to constant thermal cycling, oil exposure, and mechanical stress. Selleys Autofix Instant Gasket Black offers a modern, superior alternative. This tough RTV (Room Temperature Vulcanising) silicone rubber compound forms a custom, in-place gasket that conforms perfectly to mating surfaces, filling minor imperfections and irregularities that a pre-cut cork or paper gasket simply cannot accommodate.

Whether you’re rebuilding an engine, replacing a failed gasket, or carrying out routine mechanical maintenance, Autofix Instant Gasket Black gives you the flexibility to create a precision seal on-site without waiting on parts or cutting gasket material to shape. Its black silicone formulation is trusted by mechanics and serious DIY enthusiasts across Australia for a broad range of automotive, marine, and small engine applications — delivering a resilient, long-lasting seal that stands up to oils, fluids, and extreme operating temperatures.

Key Highlights

• RTV Silicone Rubber — Replaces Conventional Cork Gaskets — Room Temperature Vulcanising silicone cures at ambient temperature to form a tough, flexible rubber gasket in place, conforming precisely to mating surfaces and eliminating the need for pre-cut cork, paper, or fibre gaskets.
• Conforms to Surface Irregularities — Unlike rigid pre-cut gaskets, the applied silicone compound fills minor surface imperfections, warps, and machining marks between mating faces, creating a more complete and reliable seal than a conventional gasket can achieve.
• Broad Automotive Engine Application Range — Suitable for use on a comprehensive range of engine and drivetrain components including gaskets, gearboxes, water pumps, oil pans, rocker covers, timing chain covers, differential housings, and thermostat housings.
• Resistant to Oils, Fluids & Engine Temperatures — Formulated to maintain its sealing integrity when exposed to engine oils, coolants, transmission fluids, and the high operating temperatures and thermal cycling encountered in automotive engine environments.
• Flexible & Durable Once Cured — Cures to a tough yet flexible black silicone rubber that accommodates minor movement, vibration, and thermal expansion between mating components without cracking or losing adhesion over time.
• Versatile Beyond Automotive Use — Equally effective on lawn mowers, marine engines, boats, and other small engine applications, making it a genuinely versatile gasket-making compound for the home workshop, garage, and shed.
• Convenient 100mL Tube Format — The compact tube format allows for precise, controlled application directly onto mating surfaces, minimising waste and ensuring the compound is applied exactly where it’s needed.

⚠️ Application Instructions:

1. Ensure all mating surfaces are clean, dry, and free from old gasket material, oil, grease, and loose debris before application.
2. Apply a continuous, even bead of compound around the mating surface, encircling all bolt holes.
3. Assemble components immediately while the compound is still wet — do not allow to skin before assembly.
4. Tighten fasteners to the manufacturer’s specified torque.
5. Allow sufficient cure time before starting the engine or exposing the joint to fluids and operating temperatures — refer to product instructions for specific cure times.

⚠️ Safety Warnings:

• Contains acetic acid cure by-products during curing — use in a well-ventilated area and avoid prolonged inhalation of vapours during application and initial cure.
• Avoid contact with eyes and prolonged skin contact — wear gloves during application.
• If eye contact occurs, rinse immediately with water and seek medical attention.
• Keep out of reach of children.
• Not intended for use on oxygen sensors, catalytic converters, or components where silicone contamination could cause damage.
• Store with cap tightly sealed in a cool, dry place to prevent premature curing in the tube.

⚠️ Compatibility Warning: Not suitable for use in contact with oxygen sensors or in areas where silicone vapour contamination could damage sensitive engine management components. Always confirm suitability for your specific application before use.

Technical Specifications