Floating Workbench Extension




Introduction: Floating Workbench Extension

Good afternoon Instructables Land.

I wound up making a little extension shelf for my workbench. You may have noticed, I have been using my Dremel on a little slide out extension on a desk. But I am tired of getting sawdust in the main part of the house. Also it slides back and forth if I put any lateral pressure on it. While I liked the 270 degree approach angle that the little board offered, I needed something more substantial. That is when I started thinking thinking ....

***Warning the following is a train of thought and the author cannot be held responsible for any derailments. ***

...What do I have that is substantial that would withstand the rigors and stress of working on stuff? *light bulb* My workbench is substantial and I love the stupid thick heavy top. I wonder if I can get more of that desktop particle board? HMMM I could just clamp a section on top of the existing bench. However that would be too easy, besides I want it to be flush with the existing top for really big projects.

I suppose I could make bracket to support it from underneath. Then I would probably keep hitting my knees on the support and just get angry. What about a floating shelf, but beefier? One never knows unless one tries, off to the hardware store. Hmmm I better sketch this out...

I took a couple measurements of the table top, then asked the maintenance guy at work if he had any more desk parts laying around. As luck would have it he had a narrow L from a typing desk that he wanted the metal drawers for and gave me the narrow top. So the new 18.5 inch wide top was the same 1.25 Inch thick desktop that I already have.

Now I just need to cut it down to length and mount it some how.

I figured I could probably pick up some 1/2 inch steel round rod and perhaps use it to support the accessory top but I don't know how it would hold up to weight. So I did just that. The shelf was mounted using 1/2 steel rod and now Ill show you how I did it as it seems to bear weight just fine.

As always if you like what I am doing feel free to subscribe and any votes are helpful, Thank you.

Tools Used.

  • Circular saw
  • Drill with 1/4 drill bit and a 7" long x 1/2" wide ship builders auger bit
  • Reciprocating saw with metal cutting blade
  • Framing (speed) square
  • Clamps
  • Level
  • Tape measure
  • Pencil
  • Big Hammer
  • Scrap wood block


  • 18 1/2" x 36" desk top (free)
  • 1/2" x 36" Steel round stock ($6)
  • Spray Oil ( to lube the saw blade)

Step 1: Cutting It Down to Size

All right tinkerers the first step is to get the acessory table/shelf cut down to size.

I measured out precisely 16 inches from the edge to my saw blade. Then laid out my level square to function as a fence for my circular saw. If I keep the saw flush against the "fence" I should be able to rip out a nice straight edge to mount against the table. Set the depth to 1/2 inch and .....

Yeah.... So I measured out precisely 14 inches and clamped my square to compensate for the saw wandering in the last cut and proceed to cut the table top using 2 consecutive cuts as to not bog down the saw blade.

So I have a resulting shelf that is 18 1/2 inch wide by 14 inches long. And it is nice and square... well rectangular but you know what I mean.

Step 2: Drilling the Holes.

Allright now it is time to drill the holes. Since we know we need the holes exactly as it will be mounted.

  1. Using the speed square draw 2 lines, 1/2 inch from the top of the bench, and shelf finished sides
  2. Now flip the shelf over so that the lines are facing you. Clamp it into place so that it is square with the bench below and flush with the edges. the finished tops should be facing each other.
  3. Measure 4 inches in from the sides and draw a vertical line intersecting with the 2 lines drawn earlier. When the holes are drilled in this manner they should line right up with the ones in the bench top allowing the 1/2 inch bars to hold the shelf up.
  4. Drill pilot holes at the intersections of the lines ensuring that they are at 90 degree angles to the bench and shelf.
  5. After your pilot holes are drilled mount a 1/2 inch Shipbuilders auger into your drill and measure it from the chuck face to the tip of the drill omitting the pilot screw. Mine resulted in a length of about 6 inches.
  6. Drill 1/2 inch holes square to the edges of the table/shelf.

Step 3: Measure Out and Cut the 2 Bars

Ok remember that 6 inch bit depth from earlier? Now we need to cut some bar to fit into place. Assuming that there will be some residual sawdust in each hole I decided that the bars should be 11 1/2 inches in length this will allow 1/4 inch for each hole to allow for compression of sawdust.

  1. Mount the 1/2" bar into a vise
  2. Measure out and mark 11 1/2"
  3. With a metal cutting blade on a reciprocating saw. slowly cut the bar to lenth giving the piece a squirt of oil to keep the blade cool.
  4. repeat steps 2 & 3 to make a second bar.

Step 4: Drive It on Home

  1. Using the drilling hammer drive the 1/2" rods into the holes on the work bench until you get to a depth of about 5 3/4 inches
  2. Then guide the shelf onto the rods
  3. using the drilling hammer and a wood block drive the shelf into place taking care not to destroy the finished edge of the shelf.

That is it the bench now has an accessory table to allow more detail work and support wider projects.
Thanks for following along and keep tinkering on.

I was doing some measuring of the bench and the accessory shelf when I finally took a measurement from the table top 37 inches. The table saw I ordered is 36 inches from the floor to tabletop. I will just need to make a 1 inch riser for the table saw so this shelf with the bench top will make a nice longer support.



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