Features:

  • Sensor-safe, non-corrosive formula designed for superior adhesion to oily surfaces and long term durability
  • Superior resistance to powertrain fluids including engine oil, transmission fluid, gear lube and coolants
  • Retains high flexibility and eliminates the need for pre-formed, pre-cut, paper, rubber or cork gaskets; OEM specified and approved for dealership warranty requirements
  • Temperature Range -65°F to 500°F (-54°C to 260°C) intermittent
  • Suggested Applications: Valve covers, oil pans, intake manifold end seals, timing covers, and differential covers
Make the gasket you need

If you're doing small engine repair then put a tube of this stuff in your tool box. Don't have or can't get a gasket, no problem. Ultra Black can make just about any gasket you'll need. Since it is rated for high oil resistance I use it for a crankcase cover gasket, on my push mower.

Brake Fluid Resistant

My new Chinese master cylinder cover leaks like a sieve no matter how much tension is on the bail, might as well leave the cover off. So instead of removing it and sanding the flange flat I wondered if there was a brake fluid resistant gasket sealer. I let a blob cure overnight then soaked it in DOT- 3 brake fluid for a week, rinsed it and examined it for softening, smearing, stretching, deterioration, discoloration etc. No change whatsoever so I feel confident using it on the rubber seal and will. (when I get around to it) Wash and dry the seal and cover, wipe the MC flange with a damp cloth and go for it.

Excellent RTV sealant and gasket maker

This is amazing stuff. It is well worth the price. I have used it on transfer cases and differential covers by itself with no leaks. I used it on an oil pan with gasket and it made installing the gasket much easier (again no leaks). I have even used it to create a gasket for a vacuum chamber: I let it set up for an hour and then loosely placed the lid to let it cure overnight. It stuck to the chamber, not the lid, and creates a perfect seal and a gasket that is reusable. The best part is that with the caulking tube you just let a little stick out and leave it to cure and when you go to use it next time grab the little piece and pull and about 1/2" comes out solid and the tube is ready to go!

This is the stuff! Great for sealing out oil, water or any gasket making you need done!

This is the stuff! I have a roof rack on my truck and one of the screws holding it down was allowing rain water to seep into the passenger side seatbelt tray, which then leaked on my passengers. Not good! I backed that screw out, put a pea sized bead of this RTV down and I had no more leaks! This product came highly recommended to me from my mechanic buddy. Since then, I have used it to make a new gasket on a low pressure water pump housing for a small sprinkler pump and also to seal a leaking differential housing. Had I purchased the OEM gasket for that differential it would have been about $40. This RTV has many uses and is an excellent product to have on hand. I hope you found my review helpful and if so, please click the yes button below. Thanks!

Great for Resealing Delidded i7-8700Ks

I used Permatex Ultra Black to reseal my i7-8700k computer processing unit (cpu) after I "delidded" it (removed the IHS) and replaced the thermal paste with liquid metal compound. This sealant works very well to reseal the 8700k, and will probably work well with the i7-7700k or any other delidded cpu, if common sense is used; meaning apply an ultra thin layer - thinner than the factory sealant, if you plan on over clocking. I carefully applied a very very paper thin layer of Ultra Black Permatex to the Integrated Heat Shield (IHS), but just along the outer rim's edges on the underside. This was done using a plastic shopping promotional card (an extra Game Stop Rewards card) and steady hands; use soap and water to get the silicon off your hands afterwards, or use rubber gloves while applying the Permatex Ultra Black. You'll want to let this stuff dry in your relid tool or in the socket of your mamaboard clamped down for about 4 to 12 hours, however waiting longer is probably better to ensure a solid flat contact and seal. This stuff is strong, so it will hold the IHS tight if given enough time to dry out, even with only a small amount. I've seen some people put them in toaster ovens at low heat to help speed up the drying of the silicon sealant, but air and time works just as well, and less chance of something going wrong, such as the contact shifting around.

Seal it... Forget it

Excellent product. Used it when I replaced the output shaft cover on my transfer case.

Wear gloves.

My hands have never looked so manly. Lots of black crud stuck to them that won't come off. In all seriousness, wear gloves with this stuff. It's nasty. But it is definitely gooey and sealey.

works great.

I used this to seal my IHS after a 7700k delid. works great.

I recommend this product

I'm used to the silicone based products, so when I first applied this I was a little concerned since it has the consistency of whipped cream. But I followed the directions, and after a month no leaks so far with 3 differentials. It was about 32 degrees when used also. I recommend this product

Best stuff I've ever used

I use this stuff daily it seems (not really, but pretty often) as a mechanic. We get it in the 13oz tube for use in a caulk gun. The other type of RTV just doesn't compare. I'm talking about the vinegar smelling stuff, this is different. It adheres much better to surfaces than standard rtv, and as it states has better oil resistance. I have used it as the only gasket on transmission pans, differential covers, etc. I clean the surfaces up very well with brake clean and oil free rag, and put a small bead all the way around the surface, following the inside surface of the bolt holes. I've never had one leak using it, I won't go back to the regular stuff. Gasket kits from fel-pro often come with black rtv, that gets tossed and this used in it's place, I use it in addition to water pump gaskets, o-ring sealing surfaces, well lets just say anything that would benefit from rtv. I've only not used this stuff on water pump gaskets twice, and I've only had a water pump gasket leak twice. I'm going to continue using it. Some say not to because they find it hard to clean off. Well I'll tell you that this is 100x easier to clean off than those really old and been on there a really long time gaskets that were applied dry. Plus this stuff pretty much deteriorates after any decent exposure to brake clean, so spray it, wait a few minutes, and it will be soft. (This won't effect it's use as a gasket, it only gets the outer areas wet)

Full Reviews