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

I purchased this item to repair an ash fettle in an old Vermont Castings wood burning stove, and it completely exceeded my expectations outlasting an entire season of direct fire contact. The fettle was cracked into two pieces and a prior owner had drilled two holes on either side and tried to connect it with an aluminum "bridge." The repair interfered with the door closing, so I needed to seamlessly "weld" the two cast iron sides back together. Before going through the trouble of taking it to a welder and paying to have it repaired properly, I took a chance on this J-B Weld ExtremeHeat. I used a Dremel tool with a fine grinding stone and cleaned up the two broken faces, along with about 1/4 inch of the area on either side of the crack. Following the advice of another review, I then took a cotter pin, stuck it into the chuck of my battery powered drill, and used that to thoroughly stir the J-B Weld in the container (this is a one-time use container... once opened and stirred, use it and toss the rest). After stirring for just under 2 minutes, I immediately applied it to the two surfaces, pieced them together, and then spread a little more on either side to ensure a supported bond. I then set the item on a flat piece of cardboard to cure for 2 days. (NOTE: you have to support the joint while curing, because the J-B Weld provides no structural support until completely cured. While wet, the item will just fall apart again if the pieces aren't otherwise held together.) When it was done, I replaced the fettle and lit the first fire of the season (crossing my fingers at the same time). Several months and probably 100+ fires later, the piece was still holding strong like the day I put it in. The fettle sits right against the fire, and many logs have rolled into it while it was extremely hot, with no noticeable damage whatsoever. I would absolutely recommend and use the J-B Weld ExtremeHeat again on future projects. As long as the proper preparation is done, and you follow the instructions, it's an awesome product!

I used JB Weld 36901 Extreme heat. to stop and exhaust manifold leak. A section of the gasket was missing. I just wanted a temp fix so it didn't damage the head on my tractor. This stuff worked great.

Here's what is true. If seal is broken, contents can set up upon arrival. If sealed, there's no problem. You will need to provide your own mixing amd application stick. This product will not hold a broken exhaust system together. It only works well as a filler to patch hole. Even once product is mixed and dries, it will turn back to mush if soaked in water. I tested that. That is true. However, once the product fully cures after 24hrs and is subjected to exhaust temperatures of 480 to 500 degrees or more, it will fully set. It can start to bubble after it flashes off. Stinks really bad when exhaust heats up but goes away after a 20 minute drive. As you can see, my motorcycle exhaust had pin holes that needed filling. I used the entire mixture applying back over the holes as the product will settle down in the holes. Anything bigger than a BB I recommend using a metal screen for added support. Not sure how long this may last but I have gone on several 2 hour rides and it is still holding up well. I can't see this dissolving in water now that it has been fully cured by the heat of the exhaust, but time will tell. Happy so far. Just remember. It's a filler. It will not work to hold anything together.

This metallic paste is such a relief. I got it to fix a cracked spot near the bottom of our gas oven because calling a repair guy again just felt silly. one afternoon while the kids were napping, I cleaned the area, spread this on, let it cure, then baked dinner like usual. The patch stayed solid and didn’t smell weird at all, which made me really glad I tried this instead of replacing the whole thing.

I purchased this as a desperate attempt at saving my 26 year old cub cadet tractor. It is a one year only engine and developed a crack in the heat that was allowing oil to spray out. A new head used on ebay runs $200-300 and to have a shop correctly weld it is a similar price. I wire brushed the crack and used this jb weld. Let it set for 24 hours and it was solid as a rock. I have mowed about 4 times since and no signs of a leak. Will keep my old mower running for a few more years.

I followed the instructions on this product well and while it did perform better than the squeeze bottle J-B Weld high temperature muffler repair, this product still cracked under frequent hot-cold cycles on an exhaust system. It did last longer than the dedicated muffler repair product which is why it's getting at least the 3 stars.

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.

Performs as expected, reputable brand, great price!

kanon

Amazing result. Used on an old gas oven door. Unable to get parts to repair handle but this product did the trick. Very pleased.

I bought it to fill the gap developed in high pressure vessel..it is very good and handy in such situations..highly recommend.

Reparer un coude d’echapement sur un bateau le temps d’avoir la piece de rechange.

This glued me and my wifes marriage back together