In my post last week “Marking Gauge Build” a few people asked, what do you do when the width of the board you want to mark exceeds the reach of your marking gauge?. Well that is were the panel gauge comes into play. So this weekend I built one. The length of the beam seems to vary between 18″ thru 28″. I made mine 18″ long with the thought that most of my projects will be 15″ wide or less. So first the plans.