LOCTITE SI 5910 Silicone Flange Sealant for Oil Pans, Timing Covers and Flexible Flanges

LOCTITE SI 5910 Silicone Flange Sealant Benefits

LOCTITE SI 5910 Silicone Flange Sealant is designed for stamped sheet-metal covers and other flexible assemblies that may move during operation. Unlike rigid gasket materials, the cured silicone accommodates vibration, thermal expansion and normal flange movement. This flexibility helps maintain sealing contact when machinery experiences repeated heating, cooling and mechanical loading.

The ready-to-use formulation requires no resin-to-hardener measurement, reducing preparation time and mixing errors. Its non-running consistency helps operators maintain a continuous bead around corners, bolt holes and potential leakage paths. The black appearance also makes application coverage easy to inspect before assembly.

Applications for LOCTITE SI 5910 Silicone Flange Sealant

LOCTITE SI 5910 Silicone Flange Sealant is suitable for timing covers, oil pans, valve covers, transmission covers, gearbox housings, pump covers and similar flexible flanges. Henkel specifically identifies stamped sheet-metal covers and oil sumps as typical applications where oil resistance and joint-movement capability are required.

The product can also be evaluated on compatible machined or cast flange surfaces made from metal and selected plastics. It is suitable for flange gaps up to approximately 1 mm when the joint design and curing conditions are appropriate.

This form-in-place gasket can reduce the need to stock multiple precut gasket shapes. It fills surface irregularities and follows the complete sealing path after the parts are assembled. Because coatings, plastics, oils and service fluids vary, manufacturers should test the completed assembly under actual pressure, temperature and movement conditions.

LOCTITE SI 5910 Silicone Flange Sealant Technical Properties

The uncured material is a black, thixotropic oxime-silicone paste with a typical specific gravity of approximately 1.34 at 20°C. Henkel lists a tack-free time of up to 40 minutes at 25°C and 50% relative humidity. Moisture curing begins immediately after exposure to the atmosphere and progresses inward from the exposed surfaces.

After one week of curing under the specified conditions, typical properties include Shore A hardness of approximately 30, tensile strength of at least 1.7 N/mm² and elongation at break of at least 400%. These properties demonstrate the soft, flexible performance required for flanges exposed to movement.

The official product information lists an operating-temperature range from approximately -55°C to 200°C. Laboratory testing also demonstrates useful resistance to engine oil, water-glycol mixtures and long-term heat exposure under specified conditions. Published figures are typical reference values rather than guaranteed purchasing specifications.

How to Apply LOCTITE SI 5910 Silicone Flange Sealant

Remove the existing gasket and clean both flange surfaces thoroughly. The surfaces should be dry and free from grease, oil, dust, moisture and loose residue. Apply a continuous bead to one flange, surrounding bolt holes and following the complete sealing path.

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

Allow adequate curing before exposing the assembly to heavy loads, maximum pressure or demanding service fluids. Henkel gives seven days as an example of curing time before heavy service loading. Uncured excess can be removed using a compatible non-polar solvent.

Why Choose LOCTITE SI 5910 Silicone Flange Sealant?

LOCTITE SI 5910 Silicone Flange Sealant combines excellent engine-oil resistance, flexible movement capability, high-temperature performance and controlled thixotropic application. It is a practical form-in-place gasket for timing covers, oil pans, valve covers, gearboxes and industrial flange assemblies.

Store unopened packaging in a dry location, ideally between 8°C and 21°C. Review the official Henkel LOCTITE SI 5910 Technical Data Sheet and current Safety Data Sheet before qualification or production use. Explore our silicone gasket sealants for additional automotive and industrial flange-sealing solutions.