The last thing we have to do for our bench is put in a shelf. I could have done this in a variety of methods, but I chose to use some random width pine I had lying around. I’d foregone using it in other projects because it had knots in it, but for the bottom shelf of a workbench it was fine. It might not be as pretty, but it was economical.
In order to stiffen the boards under load, I used my Stanley 45 with the appropriate irons (a 1/4″ tongue/groove). One of the swinging fence planes like the Stanley 48 (or especially the Lie-Nielsen interpretation) would have been ideal for this, but so far they have proved outside the reach of my limited funds. But while the 45 takes a little fiddling, it cuts the boards just fine.
Carefully fit the boards around the legs so you don’t have a big gap. I put a couple nails through the ends of the boards into the rebate we cut before the bench was assembled. While it’s not strictly necessary, it leaves me vaguely unsettled to leave them loose, though glue is right out because it would restrict seasonal expansion. Nails,the tongue and groove construction, and a sixteenth or so of clearance allow for a little give.
And that completes the build! You could, if you so desired, put some sort of finish (not a slick film finish!) on it, but it’s unnecessary for a workbench. When I asked my wife about it, she decided against it. So I bolted her scrollsaw down to the new bench and called it done.