Here is a quick DIY project. I wanted to add a wire race (hole) to allow a lamp electrical cord to drop through the top of a built in desk. Rather than route the wire where it was unsightly.
While there are commercially available products, you can custom make your own, to the size you need. I have to give credit for the idea, or at least how I came to know about this, to my friend Paco.
In most cases I find 1 1/2 inch Black ABS pipe the best diameter. It will accommodate most sizes of plugs. You can buy 2 ft lengths in many home improvement, or plumbing stores. To make one or several you will need a section of pipe, a corresponding sized black ABS coupler, and a small can of Black ABS cement.
Using a chop saw I cut 4 rings out of a single coupler. One cut is direct center to cut out the “pipe stop” edge inside a coupler. One coupler or 4 rings will actually make 2 wire race holes.
After you cut the 4 rings. What ever the desk top material thickness is, add 1 inch to that thickness. Cut your length of pipe to the combined measurement. Cement one of the rings to the very end of the pipe. This will will use up about 3/8th of the 1 inch excess. Allow the glue to set up.
Once the glue is set up it can be smoothed using a sander, sanding block, or even a file. Once the ring and end of the pipe is shaped flush, shape any sharp edge to slightly rounded. Finish off with fine sandpaper.
The sanded area is now dull and perhaps slightly white? There are several finishing methods that work depending on what you have available. I personally use the flame of a plumbers torch. Waving it over the ABS until it turns glossy from the heat.
You could use gloss black spray paint, or perhaps a glossy clear?
Use an appropriate sized hole saw (just a bit larger than the outside diameter of the pipe (NO THE RING). For 1 1/2 pipe (Outside diameter about 1 7/8) is use a 2 inch hole saw. The pipe should drop through the hole and the ring prevent it from dropping through. An additional ring is slipped over the pipe from the underneath side (I don’t glue this second one)
By adjusting the ring up a longer piece of pipe, before gluing, you can create vertical raceways between desk and shelves about a computer monitor. Add “T” if need be. You can clean up that spaghetti mess of wiring you might have.
Great for Desktops, Counter Tops, Walls, bulkhead openings for wires in the sides of cabinets, RV Trailers, metal cases, vehicle firewalls, etc. I have even used these to run a bundle of alarm wires through a drywalled interior wall. In some cases you will want to glue both rings to secure things. Hit any abrupt cut off edges, that might cut or saw into wiring, with some sandpaper.