How to Put Silicone on Metal Gaskets

Start with a clean surface. Wipe down both metal surfaces that will sandwich the metal gasket with grease remover or mineral spirits. If you suspect grease or oil has gotten on the metal gasket, clean it as well. Take measures not to touch the mating metal surfaces with your bare hands or an oil-soaked rag once you clean them.

Apply a bead of silicone sealer around both metal surfaces that will sandwich the metal gasket. If the gasket seals around bolts, apply a ring of silicone around each bolt hole. Wait the specified amount of time the manufacturer recommends before you place the gasket onto one of the metal surfaces. In most cases, the elapsed time is 15 minutes, but it will vary depending on the brand of silicone sealer you use.

Place the metal gasket onto the silicone sealer and carefully line it up where it needs to go. For example, if the gasket has holes to allow bolts to go through the metal pieces, make sure you line up the bolt holes.

Place the other metal piece onto the gasket and line up the bolt holes you must use to secure both metal pieces together and to sandwich the gasket together.

Thread the bolts as tight as you can with your fingers but do not tighten with a wrench. Again, wait the specified amount of time to allow the silicone to firm up even further. Again, this time frame is usually 15 minutes.

Torque the bolts down to their specified torque settings, then wipe off any excess silicone that squeezes out.