Seat Grinding, Valve Lapping, and Stone Dressing

Thankfully "stone dressing" has nothing to do with salads or food but everything to do with improving engine performance. For engines to hold compression and perform to their maximum capacity, valves must rest cleanly and firmly in their "seats." Sometimes valves leak and it becomes necessary to grind valve seats clean, lap valves smooth, and in doing so to "dress" the stone (prepare & true the stone's grinding surface angle) for use.

Under Dennis' instruction, several of our mechanics had the opportunity to dress stones, grind valve seats, and lap valves yesterday. One of the unique features of our ministry at MMS is that our mechanics gain the skills they need to serve by working on actual operational aircraft. The cylinders you'll see the guys working with in the photos below are going to go back on a live airplane. That makes the stress levels a bit higher when you put the high-power grinder on an actual valve seat and pull the trigger for the first time. It doesn't take very long to grind a valve seat. Maybe only a couple seconds depending on the specific situation but if you go too far...well, then that creates a whole other learning experience.

Experience. That's what we provide the opportunity to gain at MMS. The experience of of serving in a missionary environment, the experience of growing in Christ-likeness, and yes, even the experience of working on airplanes.

Chuck and Andy dress the stone for valve seat grinding.

Gertjan prepares to pull the trigger on the valve grinder
as Andy, Dennis, Paul & Chuck observe.

Bat-Enkh assists Paul with lapping a valve.