Flue Goo is a multi-purpose furnace/refractory cement. It will bond masonry to masonry, steel to steel, and steel to masonry. Flue Goo will withstand temperatures up to 3000 degrees F without cracking or shrinking. Flue Goo is freeze/thaw stable; however, it’s still a good idea to bring it indoors in freezing weather. It comes premixed and ready to use, and is water soluble for easy cleanup. Comes in three colors: black, buff, and gray. It’s packed in 1/2 gallon, 1 gallon, or 3 1/2 gallon plastic tubs. It is not for exterior use.
You can use Flue Goo in many areas in or around a chimney. You can use Flue Goo to seal around the stove pipe going into the chimney in the thimble. You can also use it to seal a chimney liner that is installed in a fireplace to the smoke chamber. Flue Goo is recommended because of its resistant to cracking and shrinking under high heat.
Flue Goo II is used to seal the joints between two flues and set firebrick inside a fireplace. Also used if parging the smoke chamber of a fireplace. Flue Goo is easily cleaned up using a rag and water. When parging the smoke chamber it should be smoothed out using a wet sponge to make the transition into the chimney liner as smooth as possible.