Guide to RTV Colours
Date Posted:24 June 2026
RTV stands for Room Temperature Vulcanizing. Unlike a pre-cut paper, cork, or composite gasket, RTV silicone is applied as a paste that cures in place by reacting with moisture in the ambient air. The result is a flexible, formed-in-place gasket that conforms precisely to mating surfaces, sealing minor surface warps, tool marks, and imperfections that a rigid pre-cut gasket cannot bridge.
The flexibility of cured silicone also handles thermal cycling well. As engine components expand and contract with temperature changes, an RTV gasket flexes with the metal rather than cracking or losing contact pressure.
The color is not decorative. Each color represents a different silicone formulation with a specific temperature rating, cure mechanism, and intended application. Before opening any tube, it pays to know what each color is built for and what it is not.
| Factor | Standard RTV | Ultra Plus 999 |
| Temp. rating | Up to 500°F (260°C) | Up to 650°F (343°C), higher-spec formulation |
| Colors | Blue, Black, Clear, White | Grey, Blue, Red, Black |
| Sensor-safe option | No | Yes — Grey 999 and Ultra Plus 999 Grey |
| Best for | Routine service and general repairs | Performance engines, high-temp applications, sensor-equipped systems |
Complete Application guide
Clear RTV Silicone — Transparent Seal Rated to 500°FClear RTV Silicone Gasket Maker is rated up to 500°F (260°C), cures to a fully transparent, flexible seal, and is the correct choice wherever appearance matters or where a colored seal bead would be cosmetically unacceptable. It instantly forms tough, leak-proof gaskets and resists oil, coolant, water, and other fluids. Typical applications:
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White RTV Silicone — Clean Finish for Plumbing and HVACWhite RTV Silicone Gasket Maker is rated up to 500°F (260°C), cures quickly, and remains flexible after cure. It is designed for applications where a white, neutral finish is required and is commonly used in plumbing, HVAC, and sanitary environments where dark or brightly colored seals are not appropriate. Typical applications:
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Blue RTV Silicone — General-Purpose Gasket MakerBlue RTV Silicone Gasket Maker is a fast-curing, flexible sealant rated up to 500°F (260°C). It instantly forms a leak-proof, flexible gasket in place and is engineered to resist oil, coolant, water, and other automotive fluids. It is the go-to choice for a wide range of standard engine and drivetrain sealing applications. Typical applications:
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Black RTV Silicone — Oil Resistance for Sumps and CoversBlack RTV Silicone Gasket Maker is rated up to 500°F (260°C) and is formulated for maximum resistance to oil, oil additives, and petroleum-based fluids. It instantly forms leak-proof, flexible gaskets and is the standard choice for oil-flooded applications where sustained fluid contact is expected after assembly. Typical applications:
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Grey 999 RTV Silicone — Sensor-Safe, Designed for Import EnginesGrey 999 RTV Silicone Gasket Maker is a high-performance, neutral cure sealant formulated specifically for import engines and precision parts. It is rated up to 650°F (343°C) and uses a non-corrosive, low-odor neutral cure chemistry that is safe for oxygen sensors, catalytic converters, and emissions systems. It will not damage sensitive electronic components or trigger fault codes during curing. Grey 999 is designed for Japanese and European import vehicles and is the correct sensor-safe choice for any modern engine equipped with emissions controls. Typical applications:
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Ultra Plus 999 RTV Silicone — Premium High-Temp, Sensor-SafeUltra Plus® 999 RTV Silicone Gasket Maker is the premium-tier sensor-safe product in the ABRO range. It delivers super high-temperature resistance up to 650°F (343°C) with a neutral cure, low-odor, non-corrosive formula. It is oxygen sensor-safe and is specifically designed for exhaust manifolds, turbo systems, and high-performance engine components where both extreme heat and sensor safety are required. Ultra Plus 999 is available in Grey, Blue, Red, and Black, covering both sensor-safe and high-performance non-sensor applications at the premium tier. Typical applications:
The Ultra Plus 999 RTV Gasket Maker range can be found here. |
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Ultra Plus Copper RTV Silicone — 700°F Rated for Turbo EnginesUltra Plus® Copper RTV Silicone Gasket Maker is specifically engineered for 4-cylinder high-performance and turbocharged engines. It delivers the highest temperature rating in the ABRO RTV range at 700°F (371°C), with a neutral cure, low-odor, non-corrosive formula that is oxygen sensor-safe. It is the correct choice for turbo flanges, exhaust manifolds, downpipes, and other extreme-heat sealing points. Grey 999 is designed for Japanese and European import vehicles and is the correct sensor-safe choice for any modern engine equipped with emissions controls. Typical applications:
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