J-B Weld 37901 ExtremeHeat High Temperature Resistant Metallic Paste - 3 oz

This stuff is great! I patched to holes in a catalytic converter and despite the intense Heat, the product has remained intact! It's easy to mix and apply, and dries rather quickly.

Used this to patch a crack in my muffler on my 150cc scooter and so far it has worked perfectly! I live in North Texas and it's June, so it's pretty warm out even in the evenings, so I had no problems with cure time. Started to harden within a few minutes after application.I did have to mix up the product pretty well before it was ready, but that was easy. It doesn't come with something to stir/apply it, so I used a small spatula that came with another weld glue product.Seems to be holding well even with high temperatures. If it fails I will update this review, but so far so good!

I have used another one of their products that is intended for a similar use. That is more like toothpaste than a tube so it is somewhat easier to apply because you can put it on the tip of your finger and place it where need be. This comes in a extremely small jar. You have to stir it before using it so the only thing I could use was a small screwdriver. Trying to get it in on my manifold around all the obstructions It was so watery that it was difficult to not have it completely run off my finger before getting it to where I needed it to be. It's not completely liquid but it's not the paste either. Not really satisfied with how little of it you get compared to let's say the paste that the same manufacturer sells. One thing that I understand but I don't like is that you cannot apply heat to it for 24 hours. So with the amount of heat that would come off of a manifold obviously you really do have to wait It's not like an exhaust pipe that would be cooler. So the negatives were: amount given, size of container, product consistency. Waiting for it to cure so I cannot give a review on quality

Cracks over time used it to seal a intake manifold on atv worked good till it started cracking

Follow the instructions and this works well.I has a gas stovetop grate crack and the replacement price was $150 — no way! It was for the middle grate that I rarely use, so it was worth trying this.My 1st attempt I didn’t sand the connecting pieces well enough, and the second time I let it dry in a position where weight was helping the bond for 24 hours. That clearly made the difference.

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.

Used this product on a weber kettle performer grill that had a small rust through hole in it, it worked great and sealed the hole, much cheaper, since weber doesn’t make the bottom bowl to repair their product anymore….