Heat Transfer Compound, often referred to as heat transfer mastic, is a compound used to enhance the thermal performance of bolt-on heating products. The compound is applied to the bolt-on jacket at time of installation. Heat transfer compound consists of graphite and one or more binder components which are formulated for different applications. Graphite is a good heat conductor with half the thermal conductivity of aluminum and more than 100 times the conductivity of air.
For ControTrace® heating elements and panels, CSI recommends its Grade-B ControTrace® Thermal Compound. Grade-B is a non-hardening compound composed of a high-temperature petroleum derivative and graphite. Its maximum service temperature is 400°F. At room temperatures, Grade-B has the consistency of heavy grease. Its workability decreases with decreasing ambient temperature, becoming very stiff near freezing temperatures. Grade-B is not soluble in water. It will dissolve in light mineral oils. It has an unlimited shelf life and is provided in one-gallon containers.
For ControHeat® jackets, CSI recommends its Grade-1 ControHeat® Thermal Compound. Grade-1 is a hardening, water soluble compound composed of silica compounds and graphite. The silica binder causes the compound to become rigid as it dries. Once dried, it vigorously adheres to applied surfaces. Its maximum service temperature is 750°F. The consistency of Grade-1 from freshly opened containers is like a thick paste. It is workable at temperatures above freezing and should be stored above 32°F. Grade-1 has a 1-2 year shelf life and is provided in one-gallon containers. Special grades of the material are available for higher temperature service.
Material Safety Data Sheets are available for CSI’s heat transfer compound: