High-Torque Load Applications
Oil Resistant
Low Odor
Sensor Safe
Set Time
1 Hour
Cure Color
Use On
  • Automotive
  • Metal
  • Rubber
  • Silicone Sealants & Gasket Makers
  • And More

Ultimate Grey Silicone

J-B Weld Ultimate Grey Gasket Maker & Sealant is an RTV (Room Temperature Vulcanized) Silicone gasketing material designed for use in mechanical assemblies where higher torque or closely spaced bolt profiles can lead to higher loads and cause gasket and sealing failures for average silicones. Upon curing, which occurs when the product is exposed to the moisture in air, the silicone forms a tough, waterproof, gasket and seal on most surfaces. It will not shrink or crack, resists oil and petroleum products, resists weathering, is sensor safe, has good temperature resistance up to 500º F intermittent and is great for many automotive applications.

Great For
  • Import Vehicles
  • Intake Manifolds
  • Transmission Pans
  • Oil Pans
  • Timing Gear Covers
  • Cam Covers
Made in the USA US flag

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Prepare: For best results, clean and dry surface area
Apply: Apply even, continuous ¼ inch bead of Silicone to one surface area. Surround all bolt holes with Silicone.
Assemble: Reconnect parts while Silicone is wet.
Secure: Hand tighten until Silicone begins to squeeze out.
Dry: Allow drying for 1 hour and then tighten an additional ½ turn.
Finish: Scrape or cut away excess cured sealant. Silicone will fully cure in 24 hours.