Dave, my workbeanch is made from a piece of reject truck flooring, which is edge-glued 1-1/2 x 1-1/2 inch oak strips, that I got my hands on about 10 years ago. This style truck flooring is designed to be put in tractor trailer van floors which support the weight of forklifts with their loads, at about a 2 foot support beneath the flooring
My bench top is about 4' x 4', built on 4 x 4 treated pine legs. It's solid as a rock! I would think that 12/4 is a little overkill for the bench top, but I think the design of the support beneath the top has will influence the thickness of the top.
Just recently, I put in a few base cabinets in my garage area, and made a strip style worktop for them, top is approx 22 x 84 inches. I wanted to get some maple, but since the approved budget for my project was overspent, headquarters upstairs in the kitchen instructed me to do the top cheaper. So, I opted to go with 2x4's studs ripped in half. I edge glued and simply edge-nailed them, then sanded with my belt sander. I wanted only what I would call a hobby-weight work area, and it came out pretty nice. If I had to do that top over again, I would have probably gone with the same wood, but I would have built a jig and used my router to machine the top to a flatter surface.
Let us know how your project works out.
