I made a low table out of a couple of step-stools, my hollow-core door, and one of the MDF panels that would eventually form part of my top. I was concerned that any oil that dripped on the door might interfere with its glue adhesion, when I finally get around to the project for which I'd purchased it. The top side of the top sheet of MDF, though, I planned to oil, anyway. (Ditto for the bottom side of the bottom sheet.
My advice? Don't do this. If you have jointer and a planer, use them. If you don't, seriously consider using dimensional lumber that has already been planed and sanded. If you are going to try to clean up construction lumber by hand, using a hand plane is a lot faster and more pleasant than using a belt sander. Except, of course, that to do a good job of planing a board you need a solid bench to hold the board, and you don't have a bench, yet.
I’m building my second bench. I built the first years ago with wood from old machinery pallets – mostly oak and maple. Mortised the legs into the base, and pegged ’em with 1″ dowels. Of course, the legs warped a bit, but that made everything tighter and stronger. The top is 2″ thick Ash, one board cut in half and joined side to side. Wrapped a maple apron around the top, and I think I screwed the top from underneath to the leg braces. Solid. Over time, built a cabinet under for 3 drawers and a small cabinet door. Works for me.
My wife has given me the OK to buy a "Rancher"-style shed from Lowes and have it installed in the backyard. The discounted installed price will be about $2,600 and this includes the 12' x 8' structure along with a lot of upgrades (twin metal doors, a window, 2 skylights, storage, vents, etc.). I can save about $300 if I build it myself, but my skill level isn't there yet, so I'm going to pay Lowes to assemble it. (See Post #12 below for some photos of the shed and the space I have to work with.)
After I left the magazine for a new job, I did all of my woodworking in my small two-car garage, but it was a struggle. Power, lighting, and temperature control were limited. And because I shared space with our cars I was always moving machines around, often while in the middle of a project. On top of that, my tool and machine collection had long since eclipsed the space. For all these reasons, fixing up the garage wasn’t an option. My finished basement is a family room, so it was out, too. An addition to the home or a stand-alone building would have been too expensive. I had to find a better path to a shop.