Tough Metal Putty
The Hi-Temp Lab-metal one-component metal putty from Alvin Products (Everett, MA) requires no mixing, applies easily, and can be sanded or painted. According to the company, it can withstand temperatures up to 1,000°F. In addition, it is suitable for smoothing welds and filling cracks, dents, or voids, and it will not shrink. It air dries within 24 hours, and is weather-resistant.
Visit www.alvinproducts.com  to get additional information.