Permatex Ultra Red High Temperature Gasket Maker, 13 oz — Sensor-Safe, Oil-Resistant

Permatex 81624 Ultra Red High Temperature Gasket Maker is a sensor-safe, high-temperature silicone sealant designed to form reliable gaskets and repairs that resist heat, oil, and common shop fluids.

This 13 oz cartridge of Ultra Red combines high-temperature tolerance with strong adhesion and flexibility so you can create effective gaskets or dress existing ones. It meets OE silicone gasket performance specifications and is formulated for professional and DIY use where elevated temperatures and exposure to oils are expected. The product is low-odor, non-corrosive, non-flammable, and labeled sensor-safe to protect modern engine components.

How hot can this gasket maker handle?

Ultra Red is engineered for demanding thermal environments. It withstands intermittent peaks up to 650°F (399°C), making it suitable for many engine and exhaust-area repairs where silicone performance is required.

• Intermittent temperature resistance: up to 650°F (399°C)
• Continuous-use resilience for common engine temperatures
• Maintains seal integrity under thermal cycling

Will it resist oil and common shop fluids?

Yes — the formula is dual-resistant, providing durable protection against both high temperatures and exposure to oils, fuels, and typical automotive fluids. That makes it appropriate for areas where oil contamination would otherwise break down ordinary sealants.

• Oil and fluid resistant formulation for engine compartments
• Maintains adhesion when exposed to gasoline, motor oil, and coolant splashes
• Helps prevent leaks by preserving flexibility after fluid exposure

Is it safe around sensors and electronics?

Permatex designates this gasket maker as sensor-safe, meaning it is compatible with oxygen sensors and similar components when used according to instructions. Its low-odor, non-corrosive profile reduces the chance of harming nearby electronics or sensors during cure.

• Sensor-safe formulation recommended for O2 sensor areas when installed properly
• Low odor and non-corrosive to protect surrounding components
• Non-toxic and non-flammable for safer shop use

How should I apply and where is it best used?

Apply from the 13 oz cartridge with a standard caulking gun to clean, dry surfaces. It can be used as a formed gasket, as a dressing, or to replace OE silicone gaskets on flanges and covers where high heat and fluid exposure occur.

• Use on valve covers, transmission pans, water pumps, and oil pans
• Apply a continuous bead and allow recommended cure time before pressurizing
• Meets performance specs of OE silicone gaskets for many applications

Who is this for? Permatex 81624 Ultra Red High Temperature Gasket Maker is aimed at professional mechanics, restoration enthusiasts, and knowledgeable DIYers who need a high-heat, oil-resistant silicone seal for engine and exhaust-area repairs. If you require sensor-safe material, low odor, and a product that matches OE silicone gasket performance while tolerating aggressive shop conditions, this 13 oz cartridge provides a versatile, durable option.