Step 7: Preparing the Desk Top
I bought the 4x8 sheet of plywood and cut it myself, since I needed a shape they couldn't (or wouldn't?) easily cut for me at the store. But by all means; if all you need is an 8x3 section (or whatever) definitely have the store cut it for you - they typically have either a large table saw or panel saw and will do a small number of cuts on the spot for free.
Measure out the cut lines using a tape measure and straight edge. I cut the plywood using a jigsaw and got pretty good results - you could also use a circular saw. For lack of a better place to do the work, I simply laid some scrap 2x4s in the driveway and cut right on the ground. Before you do this, make sure the blade height is set so that it won't touch the ground!!
After cutting, I drilled several cable access holes using a 2.25" hole saw. Before drilling these holes, make sure you measure out where the cantilever supports are. Otherwise, you may end up with a hole right over a support! Also make sure the edge of the hole is at least 1.5" from the edge of the desk top, to avoid overlapping the horizontal support beam. Drill as many holes as you think you'll need - then add an extra just in case.
There are a few ways of finishing the edge of the table. You could give it a quick sand to remove any splinters, or you could apply some wood trim or a strip of veneer. I knew my wife would be working with textiles, which tend to snag on sharp corners. So, I decided to round over the edges with a router. I used a 1/4" roundover bit on both the top and bottom of the table on all the outer edges, as well as the cable access holes.
The last step is to sand the desk top. The veneered surface will likely be very smooth already; it may not need sanding at all! But you will probably want to sand the cut edges a bit to remove and splinters or burrs. I started by sanding the edges with a small handheld random orbit sander. I sanded the cable access holes by hand. Finally, I sanded the desk surface itself with a 5" random orbit sander.
If you like, you may paint or stain the table surface now. If you're using a particularly smelly stain, or have any other reason why it would be better to paint the table top outside of the room it will eventually be in, by all means do so at this point!