Maximum Oil Resistance
Temperature Resistant up to 500° F
Low Odor
Sensor Safe
Set Time
1 Hour
Cure Color
Use On
  • Automotive
  • Metal
  • Rubber
  • Silicone Sealants & Gasket Makers
  • And More

Ultimate Black Silicone - 3oz

J-B Weld Ultimate Black Gasket Maker & Sealant is an RTV (Room Temperature Vulcanized) Silicone gasketing material designed for use in mechanical assemblies where maximum petroleum and oil resistance is required. 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 500 F intermittent and is great for many automotive applications.

Great For
  • Oil Pans
  • Valve Covers
  • Transmission Pans
  • Timing Gear 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.