The Workbench With a Secret!




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I built a workbench for my 3D printers to get them all in one warm place. I used only hand tools, if you don't count asking the employee at the lumber yard to cut the plywood sheet for the top down to workbench size. I don't own a table saw and having it pre-cut made it easier to handle and get home.

After pausing construction of the lower shelf for the evening, I was thinking about the following days work to the shelf and I got an inspiration on a way to simply add the hidden storage the lower shelf with only a little bit more work. The word inspiration comes the belief that some ideas, the "inspired" ones, come from a divine source; "In the Spirit." Well this inspiration gave me the idea for the secret compartment built into the lower shelf, in a place where no one would ever look and with enough camouflage and articles of storage in place to dissuade anyone from even considering looking there for a hidden shelf.

This instructable is about making a lower shelf on the workbench for supply storage including the "No One Will Ever Look Here For It" secret compartment built into the lower shelf. It's not about making the whole workbench, though the skills used in this instructable can be applied to the simple construction of the whole workbench.

After getting this idea, I realized it fits into the "Hiding Places" contest, so if you like it, will you please vote for it! Thank you!

Step 1: A Workbench (Or Other) to Add a Shelf To:

Like I mentioned above, I built this workbench that I needed to add a lower shelf to, so I'd have a place to store supplies; plastic filament, tools and other supplies. You may already have a workbench or other piece of furniture that you want to add a shelf to. Or you may have plans for building a workbench in the future and with this idea you too can add secret storage to it.


A Workbench, Counter, Shelving System or other furniture you can add a shelf to

A Few Feet of Framing Lumber. In my case I had a few feet of 1" x 4" left over from construction of the main workbench.

A Few Square Feet of Plywood for the Shelf Surface and Secret Shelf. I had the remaining piece of 3/4" plywood left from the lumber stores pre-cut of the workbench top.

Enough Screws to Secure the Shelf's Framing and Surface in place.

4 to 8 "L" Brackets to Support the Secret Shelf under the Lower Shelf.

1-1/2" to 2" Nails X 3.


A Pencil

A Tape-Measure

A Cross-Cut Saw

A Hand-Held Circular Saw

A Electric Drill and Appropriate Drill Bits

A Electric (or Not) Screwdriver

Some Bar or "C" Clamps

A level

A Square

An Extension Cord

A Couple Saw Horses or Portable Workbench

Step 2: Building the Frame and Supports

First thing we to do is build the frame on the legs. Decide the height the shelf will be. You'll need it low enough to fit the tallest item you plan on storing here and high enough, if you plan on storing on the floor under the bottom shelf. I decided the plastic tubs would probably be the tallest items on the shelf so I designed the lower shelf to have space above it 1/2" taller than the plastic tubs (with their lids. Don't forget the lids!) :-)

If you have a level, you can clamp a board to the legs, making sure it's level and at the desired height and mark their location on the legs. If you don't have a level, you could measure the distance down from the top surface and mark the legs. Do not measure up from the bottom of the legs. Each leg could be a slightly different length and this would cause your bottom shelf to be unlevel an mirror the legs inaccuracy. (TIP: Besides, if you use the distance from the top and later you find the legs have different lengths, you'll still be able to correct them.)

After marking the legs for the location of the shelf, you'll need to cut the 1" x 4" boards to their correct lengths. See the attached Framing Pattern diagram. Look at the inset closely. If you just measure outside edge of a leg to the outside edge of the other leg for every board, you'll end up with 2 boards too short. I believe for aesthetics sake, you'll want the long board that faces into the room/shop (red boards in diagram) and back board to be the longer boards. Set the length of these boards to be the distance from the outer edges of the legs plus 2 times the thickness of the boards (the 2 end boards, shown in green.) (TIP: If you do your measuring near the top of the bench, it will be more accurate. Without framing, the legs of the bench may be leaning in too slightly to recognize it. Besides, if you measure at the top and apply the accurate framing boards at their planned height, they will help straighten out any lean in the legs.)

It's best if you start with the end boards. You need to clamp one frame board in the correct location on the legs and pre-drill 2 holes through the 1" x 4" into the legs at each leg. Only drill a depth of 3/4 the length of the screws. If you decide to pre-drill the screw holes, see the attached Drill Bit Sizing Diagram to figure out the size drill bit (shown in lt. blue) to use with the size of screws (shown in black) you are using. The drill bit shafts diameter (shown by "D") should be the same size or slightly smaller than the diameter of the main shaft of the screw (shown by "C"), NOT it's threads (shown by "E"). (WARNING: If you match the Bit to the Threads, you'll drill a hole too big. It will be big enough to push the screws in without turning them.) (TIP: An easy way to match the drill bit to the screw is pinch both the drill bit and screw between your thumb and index finger, with the bit in front of the screw. Hold the about a foot from your eyes with one eye closed. You should be able to see the threads behind the shank of the drill bit, but not any part of the main shaft of the screw. While it is possible to pick a drill bit too large using this method, but as long as you see threads behind the shank, you should be okay.) Just use your best judgement to get the 2 diameters the same size.

Step 3: Constructing the Middle Supports

If you just took the scrap piece left over from the lumber yard employees pre-cut, you could lay it across the frame you constructed in the previous step and screwed it down, you'd have a working shelf, but for how long? Without supports through the middle, the shelf would begin to sag over time and eventually pull itself unscrewed. Even before that, that shelf would be of little use as it bowed and sagged. Not to mention, it wouldn't look very nice.

I decided to place 2 support boards, "front to back" in the middle, dividing the space inside the frame into thirds (see the attached photo) and a "side to side" cross support between those. This defines the area for the secret chamber. These front to back boards will need to be cut to the same length as the end boards (shown as green in the Framing Pattern diagram in the previous step.)

Using the measuring tape to mark the locations (4 in all) on the frame boards for the 2 front to back support boards and use a square to draw a vertical line at the marked locations. Drill 2, evenly spaced holes on each line but don't screw the support boards in place yet. Use the measuring tape to mark the centers lengthwise of each support board. Use the square to draw a line perpendicular to the length of each board at their marked centers. Pre-drill 2 holes, evenly spaced on these lines. Now cut a board to go side to side between the these support boards with the pre-drilled holes. The length of this side to side board is the distance between the "third" lines on the frame boards minus the thickness of one board. The attached diagram labelled "Side View Of The Workbench" can help all this make sense.

(TIP: There are good reasons to assemble the 3 support boards [2 front to back and 1 side to side] before attaching them to the shelf frame boards and there are good reasons to attached the front to back boards to the shelf frame boards before attaching the side to side cross board. Either order works, each just a matter of a few things; You should decide what kind of access do you have? Do you have enough clamps to hold the support boards in place while you attach them? Things like this will help you decide which order you'll attached the supports.

Step 4: Adding Supports for the Shelf Surface

I used four 1" x 1"s, cut to the same length as the end boards and front to back support boards. I needed these to widen the tops of the support boards and add far end support to the shelf pieces.

I clamped the 1" x 1"s to the front to back boards on the far sides from each other at the tops (see the attached photos) and pre-drilled about 3 holes. 1 Each about 2" from the ends and 1 in the middle on each front to back support board top edge.

I clamped, pre-drilled and screwed the other two 1" x 1"s to the inner side of the legs. I measured first and set to same height as the shelf frame. These will support the outer edges of the lower shelf.

(TIP: If you want to get a few more inches on the ends of the shelf, you can add at least 2 opposing supports between the side to side legs you can add a couple of pieces of plywood to extend the shelf to the space between the legs.)

Step 5: Building the Bottom of Secret Chamber

I cut the remaining pieces of plywood into the 3 main parts of the bottom shelf. For me, there was a piece remaining big enough to make the bottom of the secret chamber.

After cutting it to size, I clamped the bottom piece into place. If I'd have turned the whole workbench upside down, I could just screw the bottom board in place, but screws aimed up through the shelf and into the support boards would have a serious strain on them over time and might pull out. Besides it being a lot of extra work to tun the bench over, it was easier and more sturdy to use "L" shaped brackets (inside and outside of the secret chamber.)

After clamping the board in place to be the bottom of the secret shelf, evenly place 4 "L" shaped brackets in place and mark their locations. Unclamp the board and drill/screw the "L" brackets in place on the bottom board. Reclamp the board in place and pre-drill and screw in the rest of the screws for the "L" brackets. This will hold the bottom board in place. (TIP: For extra security... before reclamping the board, I also screwed in a second set of "L" brackets on the outer edge of the bottom side of the bottom board to secure to the edges of the bottom board and support boards.)

Step 6: Adding the Bottom Shelf to the Frame/Supports

All that is left to do is add the actual shelf on top of the frame and the support boards:

With the shelf cut into thirds and all set in place, I clamped the 2 outer thirds in place and pre-drilled/screwed them. Then with the middle one clamped I picked a drill bit slightly bigger then my 3 nails and drilled 3 holes, evenly spaced along the front edge of the middle section of the shelf and with a depth into the frame longer then the nails. Now the nails can be manual placed into the holes and the shelf appears to be nailed down. (TIP: It is a give-away that only the middle sections is "nailed" down with the rest of the bench and shelves are screwed in place. You could cut screws to only fit the shelf and be too short to reach down into the frame board or drill out the holes in the frame boards to be bigger than the threads of the screws.)

You now can complete the camouflaged look by making use of the bottom shelf and start storing stuff on it! Have fun and thank you for checking out my secret chamber in the shelf project. If you like it, please vote for The Workbench with a Secret and me! Thanks again!

Hiding Places Contest 2017

Third Prize in the
Hiding Places Contest 2017



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    14 Discussions


    1 year ago

    Neat idea in real wood.. Sorry that criminals are so active that you need to hide stuff in the capital city..

    You probably do not leave your dog at home.. We have great neighbors, two or three dogs and six grand kids in Reno at any one time...

    1 reply

    Reply 1 year ago

    Thank you, iceng! And thank you for reading my instructable.

    I know what you mean. It's too bad we need hide stuff in the first place.


    1 year ago

    Very clever, I'm considering retrofitting a bench this way.

    I would make one suggestion: when drilling pilot holes in pine and other soft materials, use a bit that will yield a 75% thread, that is only the outer 75% of the threads engage in the material. In hardwoods, such as maple, oak or walnut, or other hard materials use a 50% thread. I may be misinterpreting the diagram, but it looks like it calls for a 100% thread.

    Tables for various kinds of holes and screws are readily available. If you don't have the exact size bit, select one between the 75% and 50% threads.

    Depending on the screws and material, undersizing the hole risks a jammed screw, the slot stripping out, or the head twisting off. Just last night I discovered that the person who fastened my kitchen table top to its base undersized the pilot holes. Out of six #12 wood screws, I had two without heads, and the others had stripped out and unusable Phillips slots. Fortunately, since this was an emergency, the extractors I had worked flawlessly.

    P.S. Don't use cheap screws. The cost savings aren't worth the aggravation when one or more fails.

    3 replies

    Reply 1 year ago

    Good advice on the screws.

    I found a couple of tables here showing screw diameters and pilot holes for both straight and tapered drill bits:

    Another option that removes the problem of pre-drilling completely, are self drilling structural screws.

    My favorite screws for these kind of projects are now the screws made by GRK Fasteners. They are expensive, but are real time savers. They are much thinner (for the same load bearing capability) than regular wood screws, so I have had no problems with them splitting wood.

    Home Depot and other stores carry them


    Reply 1 year ago

    Thank for sharing these links... they're very helpful!!

    Thank you for the compliment and the information. If you do retrofit a bench, I'd love to see a picture, (if you don't mind sharing the secret hiding place that is.)


    1 year ago

    Nice, thanks. I think I would add magnets to latch the cover down firmly when it's closed though.

    1 reply

    Reply 1 year ago

    Thank you! I like the idea of magnets, to sort of give a resistance if someone tries to lift it and they will probably assume it's the screws/nails.


    1 year ago

    I like it.. Maybe put the screws into the lid and then cut them down to just the heads and epoxy them in the holes. same screws as the rest, and nothing to worry about. I like the other magnet idea with this - Use the screw head to click into the magnets recessed below it! Crowdsourced Genuis!

    1 reply

    Reply 1 year ago

    Yeah, Thank you! Who would think to look for a secret storage there. Now if I only had stuff worth hiding! haha!


    1 year ago

    Very ingenious, the best hiding place is in plain sight. Nice work!

    1 reply