Review on 🔥 32oz Gry Hi Temp Cement by United States HDW MFG/U S HA KK0284-A: High Quality, Reliable and Durable by Jake Hill

I should give this one star but it barely works so I'll give it two. I used this on a pre-made mantel. There was a noticeable crack on the bottom plate and while it was still safe to use they wanted to avoid any risk and covered the bottom with this cement. I bought 3 tubs (although I only needed 1). After the first application everything looked great. It adheres well to brick and siding and applies very smoothly. I let it dry for 20 hours and then tried a propane torch. Maybe it was too aggressive but I thought it would give me more control. It bulged and bulged - it looked awful so I thought I made a mistake and did it again. I chipped and scratched as much as possible and repainted it a second time. Everything went smooth again, and after drying for a day I tried to cure it with a small kindling fire - according to the instructions. This time the curing result was even worse. It bulged and bulged badly in the hottest spots, completely breaking the smooth start (see image). I tried one last time, broke it off again and knocked it off and reattached it. Everything went smoothly and initially looked great, just like before. This time however I let it dry for 2 days and then slowly stoked the firebox with two electric space heaters which I left running for 3 hours. The box got very hot, then I let it cool and brought in the heat gun, guiding it carefully along the bottom of the fireplace. I watched it very closely and I had a thermometer to measure the surface, I checked it with my hands by waving a heat gun back and forth for about an hour. I heated it to about 200 degrees, confident that this solution would be as dry as ever. And then I gathered strips of cardboard and some paper with some thumb-thick kindling on a firewood holder and started a very small fire to finish the solidification process. Once again, by the time the kindling was lit, the temperature in the chimney had risen well over 500°...because we are FIRE, and the mortar at the bottom of the chimney began to buckle like a melon bulge, ruining the smooth look and effort that had flowed into it. Perhaps this material is suitable for repairing metal joints or corners of wood stoves, or for a limited specialty application like this. But if you're trying to create a protective layer, expect it to fail after exposure to real heat.