LOCTITE SI 587 High-Performance RTV Silicone Gasket Sealant for Oil Pans, Valve Covers and Engine Flanges

LOCTITE SI 587 Silicone Gasket Sealant Benefits

LOCTITE SI 587 Silicone Gasket Sealant provides excellent resistance to industrial lubricants and automotive engine oils. It is therefore suitable for machinery and engine assemblies where the sealing material must tolerate oil exposure, vibration, thermal cycling and normal flange movement. The flexible cured silicone absorbs shock and distributes stress across the joint instead of forming a rigid, brittle seal.

The ready-to-use, one-component formula requires no weighing or mixing. This simplifies manual maintenance work and supports repeatable dispensing in OEM production. Its non-sag consistency helps maintain bead dimensions during application, while the metallic-blue appearance makes coverage easier to inspect before the components are assembled.

Applications for LOCTITE SI 587 Silicone Gasket Sealant

This silicone sealant is designed for gasket replacement and gasket dressing on flexible or stamped metal flanges. Typical automotive and industrial applications include valve covers, rocker covers, oil pans, water pumps, intake manifolds, end seals and rear axle housings. It can also be used in pumps, gearboxes, machinery covers, compressor assemblies and plant-maintenance equipment.

LOCTITE SI 587 Silicone Gasket Sealant is also suitable for bonding and repairing fabricated silicone gaskets. Its ability to remain flexible after curing makes it valuable on assemblies that experience vibration, impact or movement caused by differences in thermal expansion.

The product adheres to a wide range of compatible substrates, but actual performance depends on surface condition, flange design, contamination, joint movement and service exposure. Production trials should be completed using the actual parts before final approval.

LOCTITE SI 587 Silicone Gasket Sealant Technical Properties

The uncured material is a metallic-blue oxime silicone paste with a typical specific gravity between 1.28 and 1.33 at 25°C. Henkel publishes a tack-free time of approximately 10 to 50 minutes when cured at 25°C and 50% relative humidity. Full performance properties normally develop over approximately 72 hours.

After seven days of curing under specified conditions, published properties include tensile strength of at least 1.6 N/mm², elongation of at least 350% and Shore A hardness between 26 and 40. This combination provides a durable elastomeric seal with high flexibility and useful mechanical strength.

The product is typically used in demanding applications at temperatures up to approximately 260°C. Actual continuous-service suitability must be confirmed according to exposure duration, flange movement, pressure, fluid type and equipment design. Published values are typical technical data rather than guaranteed purchasing specifications.

How to Apply LOCTITE SI 587 Silicone Gasket Sealant

Remove old gasket material and clean the mating surfaces thoroughly. Flanges should be dry and free from oil, grease, dirt, moisture and loose residue. Dispense a continuous bead around the flange while surrounding bolt holes and other potential leakage paths.

Assemble the components within a few minutes because moisture curing begins immediately after exposure to air. Tighten the fasteners according to the equipment manufacturer’s recommended sequence and torque. Avoid disturbing the joint while the silicone develops sufficient strength.

Uncured excess can be wiped away with a compatible non-polar solvent. Cured material may require mechanical removal with a suitable blade or scraper. Store unopened containers in a dry location between 8°C and 21°C for optimum product stability.

Why Choose LOCTITE SI 587 Silicone Gasket Sealant?

LOCTITE SI 587 Silicone Gasket Sealant combines excellent oil resistance, high-temperature performance, flexible curing, shock absorption and easy one-component application. It is a practical choice for automotive repair shops, equipment manufacturers and industrial maintenance teams requiring reliable form-in-place flange sealing.

The product should not be used in pure oxygen, oxygen-rich systems, chlorine service or other strong oxidizing environments. It is also unsuitable for constant contact with hydrocarbon fuels and concentrated strong acids. Review the official Henkel LOCTITE SI 587 Technical Data Sheet and current Safety Data Sheet before qualification or use. Explore our silicone gasket sealants for additional engine, gearbox, pump and industrial flange-sealing solutions.