Permatex 81878 Ultra Copper Maximum Temperature RTV Silicone Gasket Maker, 3 oz. Tube

This stuff works, Great seal for exhuast connection, Worked better than its sister Pipe Sealer that hardens and flakes off, I would recommend this stuff over any other i have used from same name.

Works great. My badly made NEW rear catalytic converter with a warped flange was leaking and it was giving me a code. Tried several time with different gaskets, but ended up using this silicone and a donut gasket/ Haven't got a code since. Good stuff.

The installation of the exhaust manifold went well! Time will tell if the repair holds or not.

Im a firm believer in a layer of RTV on all exhaust side gaskets. This plus proper gasketing and torque will save you the headache of exhaust leads.

Good products.

If you're working on anything high-heat, like an exhaust manifold or turbo application, this is the only gasket maker to use. The Ultra Copper RTV is a workhorse—it handles maximum temperatures without breaking down, shrinking, or leaking. It goes on smoothly, cures quickly, and forms a super durable, tight seal. I've used it on headers where standard RTV would just burn up, and this holds strong. It's the professional choice for reliability under extreme heat. Essential for engine work.

Exactly what I needed for the gym’s old fireplace doors in the break room. The seal around the glass was cracked and staff kept complaining about cold drafts. I used this sealer during a weekend cleanup. I cut it to size, pushed it in with a putty knife, and it grabbed right away. No weird smell, and it handled the heat fine after a full day of use. The next Monday my trainers walked in and said the room finally stayed warm. That alone made me glad I ordered it. Now I do not hear complaints during winter coffee breaks.

Works right do I use this for valve cover gasket on small engines?

Este sellador de silicona de alta temperatura ha funcionado de manera excelente en las uniones del escape de mi motocicleta. Su resistencia al calor extremo garantiza un sellado duradero sin deteriorarse con el tiempo. La aplicación es sencilla y la adherencia es muy buena, asegurando que no haya fugas ni vibraciones molestas en las conexiones. Además, su formulación a base de cobre proporciona una excelente conductividad térmica y estabilidad en condiciones exigentes. En general, un producto confiable y altamente recomendable para sellar uniones expuestas a altas temperaturas, como sistemas de escape y componentes de motor. ¡Gran desempeño!

Sehr gutes Produkt.

Five stars for a tube of sealant that appears to understand its role in life perfectly: go where it’s put, stay there, and stop important things from leaking out. Permatex Ultra Copper is excellent stuff. It applies well, spreads nicely, and gives you that reassuring sense that you are using a product designed by people who have met an engine and bear it no ill will. I used it for a gasket job where you very much want reliability over theatrics, and it behaved impeccably. What I liked most was that it felt properly substantial and easy to work with. Not too runny, not awkward, and it set up well. Once cured, it gave a solid, dependable seal and inspired far more confidence than some cheaper alternatives that seem to regard sealing as more of a philosophical suggestion. It’s the sort of thing you keep in the toolbox because sooner or later something hot, mechanical, and faintly temperamental will require attention. When that moment comes, this is exactly the kind of product you want on your side. Very good quality, does the job properly, and well worth having around

gasket van kamado joe classic gelijmd (stuk dat loshing) en 24u laten rusten met klep dicht. Ziet er voorlopig goed uit!

Product works very well, let is harden for at least 24 hours ! Exhaust leak resolved.. A+