Permatex 81878-12PK Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. (Pack of 12)

Works great to seal V-Band connections on my downpipe. I was getting leaks from the V-Band with the metal to metal connection. I decided to try this RTV to seal the leaks. Initial impression, it’s working good. I don’t hear any exhaust leaks.

This is good copper gasket maker and seal.

I used this for the various sealant requirements in my recent Mazda rotary engine rebuild. Rotor housing feet, front pulley bolt, oil pan. The color makes it stand out so when I got some squeeze-out from putting a little too much on the rotor feet, I could easily remove it before the oil pan was installed. The temperature range seems way overkill for this, but that's not a bad thing. While not specific to this RTV alone, make sure you clean the nozzle with a nail. Between uses you'll get boogers in your bead or a clog in the nozzle and nobody wants that.

It works exceptionally well, the only thing I didn't like is that if you don't finish it all, it tends to get hard even if you seal the lid well it gets somewhat hard and it no longer works as well.

Good product.

Used it on a few things. So far so good. Unfortunately I did not read that it's NOT good for oil and gas products. The main reason I got it was to seal an intake leak on old cast iron head.

I used this to seal up a cat back exhaust on my Jeep. Easy to apply and spread a thick bead around the pipe. Makes for easy removal if you have to take the pipes apart later. Good quality product that helps speed up install.

I’m a retired mechanic and over the years I’ve used many different gasket sealers. I have a clear favorite that never let me down and this Copper is the Best in my opinion. Do yourself a favor and get this if you don’t like oil leaks.