These are the types of work cartswere referring to.
Theyre useful, but can quickly turn into an unorganized pile of whatever you toss into them.
Using 3/8 plywood, mark out the dimensions of the tray and cut your pieces to fit.
For more, check out the video above (or linked below).
Mark has a full walkthrough of how he customized his work cart in the video.
Make storage trays for socket set| Mark Massingill (YouTube)
