Joint compound acts as a sealant to create seal between the pipes. A joint compound is a mixture of several substances including clay, vegetable oil, kaolin, rosin and ethanol. It serves both as a lubricant and a sealant for threaded joints. Use of pipe joint compound on the threads of a pipe joint helps to ensure a water and air-tight seal.
If you want the best joint compound for better fitting and connection of the pipes, then check out the products provided by Sheridan Supply.