Go to Lowe's or Home Depot(or whatever similar that you have) and get an inexpensive hollow core door and two or three ceiling tiles. Glue the tiles flat to the door(use a few weights If necessary while the glue dries). The door was a bit long for my shop table so I cut about 12 inches off one end. I then cut off the reinforced end off the removed 12 inch piece and epoxied it back to the door work surface to keep the cut end rigid. I'm now on my fourth plane on that one door. When the ceiling tiles get messed up after a few builds, just turn the door over and add a new set of tiles on the other side for a fresh new surface.