Dielectric grease is a simple compound of oil and silica filler that’s very hydrophobic and is excellent at sealing out moisture and preventing corrosion. It is an electrical insulator or dielectric, and while a popular material for batteries, power outlets, light bulbs and spark plugs, its use is often misunderstood. The trick with using a dielectric grease is knowing where to apply it to seal the electrical contacts from moisture ingress and prevent arcing while not impeding current flow.
Where to put dielectric grease on spark plugs
As mentioned above, because it’s an electrical insulator, caution must be taken on where to put dielectric grease on. Spark plug terminals are an ideal area as the grease applied here will prevent the spark from the ignition coil from arcing around the spark plug boot to ground. When doing this, you must take caution not to get any grease on the metal terminal, as this will hinder the electrical connection. You can also apply dielectric grease to the inside of the spark plug boot to add more electrical insulation. Figure 1 below helps to illustrate this concept.
Is Dielectric Grease Necessary for Spark Plugs?
Strictly speaking, dielectric grease is not necessary for spark plugs to function; however, as noted above, it is a cheap, easy-to-use material that helps ensure the current moves through the spark plug into the ignition system. MG Chemicals’ 8462 dielectric grease is available in multiple packaging options for your convenience and volume requirements. Please get in contact with Technical Support to discuss your dielectric grease needs.