Spark plugs to be reconditioned should be thoroughly cleaned of all grease and soluble combustion deposits by either of
the following methods:
A. Solvent Method
Solvent Cleaning Chamber-This can be made locally using either 1/32" or 1/16" sheet
metal steel stock. Vary the area and depth to handle available trays. Hold the solvent
level to a point at least 1/2'' below top of spark plug shield.
1. Place the spark plugs in an appropriate type metal holding tray. Electrode Ends Down.
2. Immerse tray full of spark plugs (shielded types 2/3 overall length only; nonshielded types completely) into a
suitable container of degreasing solvent.
3. Let tray of plugs soak for 20 to 30 minutes, after which, remove and allow to drain for one minute.
4. Thoroughly dry each spark plug by air blasting. A moist or damp firing end cavity will result in the accumulation
of cleaning compound between the shell and ceramic insulator during the abrasive blast operation (see section