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

I got a used smoker off Facebook that had a few gaps in the welds smoke was escaping. I got this stuff to seal up those gaps. It was easy to stir up and apply. I worked it into the cracks and then let it sit 24+ hours to set. Fired up the smoker for a bit just to check and it had sealed up perfectly.

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!

The media could not be loaded. First if all, some reviews claim there isn't 3 ounces of material in the container. The one I received weighed 3.2 ounces in the plastic cup, without the lid, so it seems to me that 3 ounces is accurate.It was enough material to serve as "formed in place" gasket for two sheet metal patches for a cheap, thin-wall tubular header for my old Honda Accord (the two tack welds that attached a support bracket broke off, leaving two holes in the tubes). I used about half of the material, but once mixed, the remaining material will eventually set (even though the leftover material at the bottom of the cup was still soft and un-set a week after I mixed it).I took some pics and a video to show how this JB Weld extreme heat material looks when delivered to you, and how thick it is after it's thoroughly mixed. It's thicker than a Wendy's Blizzard, but it will still run and drop while it's setting. It does harden pretty fast though, I could see it thickening within a couple-three minutes of application.To my knowledge, I've had no issues with this JB Weld extreme heat version coming apart on my patched exhaust header, but in my application, I have hose clamps securing the patches, and where it is under the car, I can't easily check and see if any of the JB Weld material has cracked off. But the sound of the vehicle's exhaust being quiet tells me it's holding together/sealed.I prepped the material very thoroughly of course (a file to roughen the surface and remove contaminants, then 80 grit sandpaper to do more prep, then two wipedowns with rubbing alcohol before applying the JB Weld and patches).

Love J-B Weld's paste ability to create strong and lasting repairs. I used this to make a lazy Susan for my pizza oven, It has held up great. Can be used repairs to iron, steel and metal in high temperature.

Works great broke and egr cover used this to glue it together and works great been a week of use now

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.

This stuff is awesome! Patched a bullet hole on my gas grill.