ULTIMATE GREY GASKET MAKER & SEALANT
ULTIMATE GREY GASKET MAKER & SEALANT
ULTIMATE GREY GASKET MAKER & SEALANT
SKU: 32327

ULTIMATE GREY GASKET MAKER & SEALANT

$7.99

Attributes

Low Odor
Sensor Safe
Oil Resistant
High Temperature
Water Resistant

Use On

Metal
Automotive

Product Details

J-B Weld Ultimate Grey Gasket Maker and 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 700°F intermittent and is great for many automotive applications.

Get the Safety Data Sheet

Product Attributes

Set Time
1 Hour
Dry Color
Gray

Surfaces

Metal
Automotive

How to Use

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.

Frequently Asked Questions

How is Ultimate Grey different from Ultimate Black and Ultimate Copper?

All three are neutral-cure oxime silicones, but they are aimed at different jobs. Ultimate Grey is built for assemblies with high torque or closely spaced bolts that put heavy load on the seal, and is rated to 500 F intermittent. Ultimate Black goes to 700 F intermittent and offers the highest oil and petroleum resistance. Ultimate Copper also reaches 700 F and suits high-heat exhaust work.

Is Ultimate Grey resistant to coolant and antifreeze?

Yes. It is not affected by ethylene glycol and has been used on engine cooling systems for years, which makes it a standard choice for water pump housings, thermostat housings, and coolant passage flanges. It also resists oil and petroleum products and is water resistant. It is not resistant to gasoline or diesel, which dissolve every RTV silicone.

Can Ultimate Grey be used on aluminum, glass, and painted surfaces?

Yes, and it is the one J-B Weld support recommends for those surfaces. As a neutral oxime silicone it does not release acetic acid while curing, so it will not etch aluminum castings, mirrors, or paint the way an acid-cure sealant can. It also gives a stronger bond on glass and is dense enough to hold up on boost-pressure joints such as supercharger housings.

Can I use Ultimate Grey as a thread sealer or threadlocker?

No. A threadlocker is an anaerobic product that cures in the absence of air inside the threads, which is completely different chemistry from an RTV silicone. For locking threaded fasteners use Perma-Lock Blue 24206 for medium strength or Perma-Lock Red 27106 for high strength. Ultimate Grey belongs on flange faces and mating surfaces, not on threads.

What is the shelf life of Ultimate Grey, and how do I read the date code?

Unopened, it has a two-year shelf life, and once opened it should be used within about six months because the tube starts to skin over. The date code is stamped on the crimp or the bottom of the tube as a Julian date: the first two digits are the year and the next three are the day of that year. Do not let it freeze in storage.

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