J-B Weld37901 ExtremeHeat High Temperature Resistant Metallic Paste - 3 oz

this stuff works!!had a small hole in the exhaust header of my truck. about the size of a dime. I opened the package, stirred it around a bit (settled during shipment, etc.) applied it direct to the header and that was about 3 weeks ago. Still holding strong. The exhaust headers on the motor probably get up to the 700'ish degrees F at the least. So high heat, good bond, works as advertised! Also, i did sand the area to bare metal before applying, I'd recommend this just to be sure to get a good bond.

Completely sealed all 3 leaks I had but had to buy 3 so if you have multiple leaks highly recommend having to much vs too little; also super easy to apply

Worked great on one of out gas grill burners. But, went to use it again three weeks later to glue a plant hanger and, it was dried up. Love the product but, 8 dollars for a minor repair gets pricey. Cheaper in the long run for me to buy new burners for the grill.

I used J-B Weld Extreme Heat to patch a pinhole in a 64qt stainless steel pot. After applying and letting it cure, I placed the pot on a propane burner for over 3 hours. Despite the high heat and long duration, there were no leaks at all. The product held up exactly as advertised—super impressed with its performance under extreme temperatures. Highly recommended if you need a high-temp, durable fix.

Used to patch exhaust on wife's minivan with 300k on it. Shop wanted 150 to weld it back together. This worked for me.

I prepared all surfaces with a Dremel with and wire brush attachment. All surfaces became shiny, clean metal.First impression of the product - very small. It says 3 ounces, but that's by weight, so obviously much smaller than 3 fluid ounces. That said, it also weighed less than 3 ounces on a tested scale even with the tub included, so I feel like I've been cheated.Next point: it was a thick, dense paste, not the liquid you see on the videos. I would guess that was because the foil was damaged or not properly sealed. It was the correct color: separate tan/black before mixing and cement gray after, but mixing took quite a lot of effort, because it felt like nearly cured cement when mixing.I did each step quickly, with no time between opening, mixing, and applying, so as not to allow it to cure prematurely. Being a nearly-dry cement consistency, It didn't want to adhere at all when applying it to the clean metal. I forced it to stay on by placing wood objects to keep it in place.I waited around around 30 hours. My setup to keep things in place worked. The epoxy became completely dry, but not strong at all. The very light metal parts separated with almost no effort beyond the parts' own weight. I was attaching a very light heat shield to a vehicle floor. The heat shield had two good bolts already holding one side and middle; I was just attaching the other side where the stud had broken from the vehicle floor. The bond didn't even last long enough to give the vehicle a test drive. The epoxy was just barely stronger than a dried sand castle. Strong enough to hold its shape, but noting else. I can crumble it with my fingers despite it having been given time to dry completely.In closing, this job took a lot of time and effort, and it was quite frustrating and discouraging to see the results. I will attempt to return this to the seller. Regular JB Weld has been good stuff, but this extreme heat version turned out to be a total failure.

So i got a car with a cracked engine block, it was leaking coolant. I thought i give high heat a try, even though the coolant doesn't get that hot. Anyways, the problem with this stuff is it ONLY cures when under heat! I let it cure for 16 hours, and it came right off of the block. So i tried again and let it sit for about 36 hours, plus some time with a heat gun on it. That didn't work either!I ended up using normal JB weld and let it dry overnight. That worked.

good stuff. JB Weld has an excellent reputation. I am not disappointed. Would buy again.