I made two for my shop. I used pieces of 4x4 for the legs, edged around with pieces of 1x4 and a piece of 3' x 8' 3/4" plywood for the top. The left over piece of plywood that was 1'x8' was fastened to the back side to act as a splash panel. I'm fairly tall, so I used legs that are 4' long. I used some more pieces of 1x4 to brace the lower ends of the legs. I put a shelf under one of the benches but left the other one open.
My other workbench is a WWII surplus unit that is about 3' x 10' and made entirely of hardwood! The sucker must weigh close to 400 lbs! The top is made up of pieces of hardwood that are 1'x4"x10' long. The 4" side is vertical and all of the strips are held together by pieces of threaded rod with a heavy spring on one end. That way, if the wood swells, it will compress the spring and if it contracts, the spring will keep the top solid. I think it was originally built to go on the hangar deck of an aircraft carrier but that is just a guess!
