Best Gasket Sealers of 2026

"I've relied on this RTV for multiple car repairs, and it consistently delivers a tough, leak-proof seal that stands up to high pressure and vibration. The application is straightforward and mess-free, and knowing it's sensor-safe makes it my go-to for engine work. The tube lasts a good while, and I always get dependable, long-term results."

"For anyone who goes through a lot of RTV, this big tube is a great buy. I've used it on everything from metal-to-plastic repairs to sealing a throttle body with a broken bolt, and it's held up for years, even with constant heat and oil exposure. The flow control with a caulk gun is a bonus, and I really like how versatile and reliable this stuff is."

"My 2007 Altima needed a new oil pan seal, and this Permatex RTV worked perfectly—no more leaks, just as recommended in the manual. The precut tip made the job easier, and I appreciate being able to save and reuse the tube. The only thing is it does need time to cure properly, so patience is key for the best results."

"I used this RTV as both an adhesive and potting compound for a circuit board wiring harness. The 'sensor safe' formula means minimal outgassing and no risk of corrosion. It cured fully in a few days, securely holding the wires, and I like that I can peel it off for repairs. For the price, it was an effective solution, and I still have plenty left after fixing multiple assemblies."

"This worked perfectly for sealing my Mazda CX-5 transmission fluid pan. Six months later and still no leaks—it's durable and easy to clean."

"Permatex RTV gasket makers are always straightforward, reliable, and easy to apply. They don’t dry too quickly, so I never feel rushed. Great adhesion, excellent sealing, and no leaks even after extended use."

"I've been using this product for years on motor rebuilds, and every new version continues to be a top-quality item. It's especially good as an exhaust gasket sealer, even for older, pitted headers."

"I recently used this RTV silicone for my intake manifold installation and was thoroughly impressed. It applied smoothly, created a strong, durable seal, and handled high temperatures and pressure effortlessly. I highly recommend it for any automotive sealing job!"

"While the sealing capability is fantastic and my oil pan gasket feels solid, the tube was tough to squeeze and eventually broke before I finished. Still, I'm confident the repair will last the life of my car."

"As a dedicated DIYer and car enthusiast, I can confidently say this gasket maker delivers outstanding oil resistance, reliable sealing, and impressive flexibility. It has never let me down, even on challenging engine projects. The sensor-safe and non-corrosive formula gives me peace of mind, and the product’s ease of use makes it a staple in my toolbox."

"This gasket maker is a real game-changer for quick repairs. It sets in just 90 minutes, allowing me to finish jobs efficiently. Even though it's a bit pricier, the quality and fast drying time make it well worth it for both beginners and pros."

"When sealing my oil pan, I found the adhesion to be extremely strong. There have been zero leaks and long-lasting performance. The tube does require a bit of effort to squeeze, but the durability and easy cleanup make it a reliable choice for any sealing task."

"If you're tackling any high-heat projects like exhaust manifolds or turbo setups, this gasket maker is my top pick. The Ultra Copper RTV is incredibly durable—it stands up to the highest temperatures without breaking down, shrinking, or leaking. Application is smooth, cure time is quick, and the seal is rock-solid. I've put it to the test on headers where other products failed, but this one holds up every time. It's a must-have for serious engine work."

"I've used this on several projects, and I’m impressed by its strong adhesive strength and outstanding heat resistance. Even after hours of continuous heat, the bond doesn’t weaken. However, the bottle's packaging could be improved—it burst open at the back when I applied a bit too much pressure. The product itself is excellent, though, just be gentle with the tube."

"For sealing the exhaust joints on my motorcycle, this high-temp silicone sealant performed exceptionally well. Its resistance to extreme heat means the seal stays intact over time, with no leaks or annoying vibrations. The application process was straightforward, and the copper-based formula ensures great thermal stability. I highly recommend it for anyone dealing with exhaust systems or engine components exposed to high temperatures."

"I've used this sealant for multiple water pump installations, and it always prevents leaks when I follow the instructions carefully. It gives me confidence that the job is done right."

"As a mechanic, I appreciate how this product makes gasket installation so much easier. A small bead holds the gasket perfectly, and I no longer worry about leaks or having to redo the job. Highly recommend for any shop."

"While the tube is a bit small, there’s just enough to seal the thermostat housing on my Toyota 1MZ-FE. It does the job well, but I might go for a larger size next time."

"I’ve been using this sealant on my farm tractor's leaking fuel valve and even on my riding mower’s carburetor, and it’s outperformed my expectations. No leaks after days of heavy use, and I might even skip replacing the parts I ordered because this stuff works so well. Just make sure to clean the area well before applying, and you’ll get a solid, lasting seal."

"After struggling with a leaking crush washer on my new fuel filter, I tried this product and it completely solved the problem. Multiple washers and precise torquing failed, but this sealant did the trick. Really effective for stubborn leaks."

"When I rebuilt an old engine, I kept seeing Aviation No.3 recommended as the top gasket dressing. I used it for freeze plugs and intake joints, and it worked great. Just be prepared for a sticky cleanup—I found that denatured alcohol makes wiping up much easier."

"My Honda engine has plenty of power, and I've found that Hondabond is the only gasket sealer I'll ever trust. It's always worked perfectly for me and is incredibly easy to use."

"When I received my order, I noticed the part number didn't match the one shown online. Even though the liquid gasket should still work as a replacement, I would prefer to get exactly what I paid for."

"I swear by this product for high-temp sealing and easy application. It dries fast and creates a tough, leak-free bond. I use it for exhaust gaskets and headers—the copper really helps with heat resistance. It’s a must-have for anyone serious about reliable, long-lasting engine repairs."

"Whenever I’m rebuilding a small block Chevy, I always use this spray on both sides of the head gasket. The tacky surface keeps things in place during assembly, and the copper helps with better heat transfer, keeping the engine cooler. Honestly, it’s like spraying on a layer of protection—plus, it looks like you’re coating everything in gold! I wouldn’t build without it."

"After replacing the clutch springs on my Bonneville T100, I used this spray for the clutch cover. It made sealing so much easier and I’ve had no oil leaks since. Just make sure you clean the surfaces first. It’s a real game changer for DIY repairs."

"After years with my 1996 Subaru Outback Impreza, I was ready to send it to the scrapyard due to severe overheating and a failing head gasket. Spending just $50 on this sealer gave me a functional car again, which is incredible compared to a $1600 repair quote. It took two rounds of application, but it worked—my car now starts without any issues and runs cooler than before. Even if I have to use another bottle every few months, it's far cheaper than a new car payment, and I get to keep driving my beloved 'OldBaru.' For anyone deciding between this and the junkyard, this product is a true lifesaver."

"When my 2004 Toyota Matrix developed a slow head gasket leak, I didn't have the budget for another rebuild. After a thorough flush and following the instructions, the product stopped the leak and let me drive 20,000 more miles without major issues. It bought me years of extra use, even towing another car at times. It's not a permanent fix, but for those short on funds, it's a great way to keep a car running until you can afford a real repair or replacement."

"Funcionó bastante excelente, solo tuve que esperar a que el líquido reposara y repetir el proceso para que sellara bien. El truco de dejarlo reposar un día ayudó a que funcionara mejor. Fue una solución efectiva para mi problema de fuga."