Intro: Modular Plywood Workbench
Up until now I only had a cardboard Ikea table to do my projects on. And you can understand that this doesn't work well for stuff as woodworking or putting a large metal bench vise on. That was why I started the build of my modular plywood workbench.
The workbench is made completely of plywood and can easily be adjusted by designing and building modules. The legs contain multiple mortises for this purpose. Also the top piece of the top is supposed to be replaceable. This means it can be used as a clamping surface just by screwing clamping blocks direct onto the top. If combined with a workbench vise these blocks can act as a replacement for benchdogs.
Step 1: Materials
- Birch plywood, 18 mm - amount of plates depends on the size of the plate. I made a saw plan for my design and the size of the plates. While making your saw plan and during sawing take into account the wood grain. For example I wanted the grain to lie in the direction of the table and legs, so I needed a lay-out which provided that.
- (Birch plywood, 15 mm - The first delivery of my wood supplier was wrong but already cut to size by them so I could keep it because they couldn't use it anymore. So I used this wood for an extra layer in the top for extra mass. However this is not necessary for a good plywood workbench, 2 layers will do.)
- A lot of screws
- 3x30 PZ1- used for the legs, stretchers and the bottom plate of the top. I used 30 per leg, 8 per small stretcher, 23 per normal long stretcher, 18 for the front long stretcher, 6 for the block top and 10 for the desk top, which makes a total of 292.
- 4.5x70 T20 - used for the assembly. You need 8 per stretcher, at least 4 for the depth plate and 4 for the 'depth' stretchers. This makes a total of 48
- 4x40 PZ2 - used for the top and shelves. At least 6 per shelve, approximately 15 for the block top and approximately 27 for the desk top, which makes 54 screws.
- Drill + drill bits 2 and 3 mm. Size 2 for the 4x40 screws, size 3 for the 4.5x70 screws.
- Cordless drill + screw bits PZ1, PZ2 and T20.
- Chop saw, used for cutting the strokes for the legs and stretchers to length.
- Circular saw or table saw, used for cutting the tops and shelves. (Also necessary if the majority of the cutting is done at the wood supplier.)
- Jigsaw, used for adjusting one of the strechers so your legs fit under the desk while sitting on a chair.
- Various clamps (including homemade wooden bar clamps) for clamping of the glued parts and for holding the frame in position during assembly.
- Tools for applying lacquer or oil, I used a brush and pieces of fabric.
- Something for sanding. I used 80 and 180 sanding paper and sanded by hand, but is would have gone much faster with for example an orbital sander or something of the sort.
Choice of screw:
For this build I used 3 types of screws and all with a reason other than only that I had them lying around (which I had). There are several things to consider when choosing the right kind of screw for your project, basic things like length and width, but also things such as visibility, aesthetics and applied material. I will give a small explanation why I choose the screws I choose.
- 3x30 PZ1 - The choice for this screw is very simple. When holding 2 layers of plywood together, the screw isn't supposed to penetrate the second layer entirely, which gives me a maximum length of 30 mm; more length is more strength, so 30 mm length was chosen. I wanted to drive these screws in easily without pre-drilling, so 3 mm is a good size. These screws are sandwiched between multiple layers of wood, so they need to be flush with the wood, so a countersunk screw was needed. Because these screws are only inserted once and are not meant to be loosened (legs, stretchers and the bottom layer of the tops) I choose for the (common) pozidrive head, of which size 1 is the size used for 3x30 screws.
- 4.5x70 T20 - These screws are for assembly, so they need to withstand some force. This meant a screw at least 4 mm thick. The legs are 90 mm thick, so they need to be smaller than 80 mm in length (safety factor of 10 mm). I want them flush with the wood because in future use I want to be able to clamp pieces of wood to the side. so a countersunk screw. And lastly it is a modular workbench, so you want to be able to dismantle the modular part. This means multiple time use, which provided me with Torx. The block itself doesn't need to be dismantled, but I tried to use the same screws for the same job. I had 4.5x70 screws with a Torx head, so that was my choice. Like for the 3x30 the T20 is the standard size for these screws.
- 4x40 PZ2 - For these screws I didn't have much requirements for the thickness other than it could not split the wood for the shelves. For the length it had to fasten the top two layers of the tops, which gave a length of 40 mm. And countersunk would be nice so I wouldn't hit my knee when sitting on the desk. 4x40 PZ2 is the most regular countersunk screw I use and have, so this was what I choose.
Step 2: Design
I started the design with a bunch of requirements. Searched online for inspiration and based my design on some of the things I found. The requirements and their explanation can be found below. Renders of the actual design can be found in the images and a SketchUp file of the workbench is added in this step.
Woodworking - For a long time I'm a big fan of YouTube woodworkers. With my dad being a carpenter I want to do more and more woodworking. So a woodworking workbench is the way to go. This means a wooden bench with a lot of mass (for example necessary for hand-planing) and options to clamp projects to the table (planing, sawing, carving, etc.). A lot of mass means a wooden bench. Clamping usually means holes in the top with benchdogs. I'm planning on making a replaceable top on which pieces of wood can be screwed to act as benchdogs.
Modular - I now live at an apartment on the 6th floor, but I already know that we will move to a larger house with a workshop attached in a couple of years. So at this moment I don't have much room for a large workbench, but at that time I want to be able to use this bench to it's full potential when I move and possibly expand it. So a modular workbench is easily adjusted when moving it to another workshop.
Desk - Besides woodworking and metalwork we will use it a lot for crafts which are easiest to do when sitting at a desk. So it needed to be desk height, approximately 70 to 75 cm. With a woodworking workbench in mind this is low, since they are often between 80 an 95 cm depending on your preference. That means multiple levels.
Multiple levels - When in a larger workshop, I need some more electric tools. For some larger electric tools such as a miter saw it is very convenient to place them at a lower level then the rest of the surface. This and the idea for a desk resulted in the option to place modules at multiple levels in the legs.
Plywood - I wanted to make my bench using mortise and tenon joints. But my woodworking skills are not yet very advanced so making those by hand would be pretty hard. By laminating plywood to form legs, stretchers, etc. mortise and tenon would be possible for me and I could test my wood gluing skills.
Fit through door - On a good woodworking workbench you can work on both sides of the bench from both sides. So on average it's not very deep. Desks on the other hand are deeper, PC monitor, keyboard, lot's of other stuff and still room for papers between you and the monitor. To compensate the depth is chosen such that is can fit easily through the door, 70 cm.
Step 3: Preparation
I started my preparations by cutting all the wood to its final dimensions. For convenience I let my wood supplier cut all the 90 mm strokes. This saves a lot of time and effort. Cutting the 90 mm pieces to length I did myself using a miter saw. The larger plates were cut using a circular saw. Plates of the same size were cut simultaneous to get a perfect fit during assembly. After cutting everything to size I sanded all the wood using 80 and 180 grid sandpaper and cleaned all the wood to prepare it for gluing.
- Saw direction - Like I already mentioned in the material section for the saw plan, you need to take into account the grain of the wood. For a perfect finish of your workbench you want the wood layers to be crossed such that a nice pattern can be seen. Since (most) plywood consist of an uneven amount of layers (this is such that the grain on both sides of the plywood is in the same direction) legs for example need to be cut in 2 direction for consistency. For a more clear understanding I added a picture.
- Stroke size - If you are planning on a perfect finish then you want to cut you legs after gluing them in order to obtain a smooth surface. In this case you need to cut your 90 mm strokes a little bit larger such that the legs can be trimmed to 90 mm x 90 mm after gluing.
Step 4: Construction - Frame Parts
One of the most difficult parts of the build was the glue-up of all the legs and other parts of the frame. I used both glue and screws for the assembly such that the assembly was as easy as possible and no screws were visible in the final result. The pictures in this step should give a good impression on how the legs and stretchers are assembled. A step-by-step instruction summary is given below for a complete overview.
- Use scrap pieces of the 90 mm strokes wrapped in wax paper as spacer.
- Put glue on one of the pieces and screw them together.
- Use the wrapped scrap pieces of wood as spacer and finish the first two layers.
- Glue the just attached pieces of wood and screw the third layer on.
- Clamp the assembly and let it dry.
- Assemble the other 2 layers of wood the same way (but separate from the first three layers).
- Once the piece of 3 and the piece of two layers are dried they can be put together.
- Glue both parts.
- Put the pieces together and clamp until the glue is dried.
- Use scrap pieces of the 90 mm strokes wrapped in wax paper as spacer.
- Put glue on one of the pieces and screw them together.
- Use the wrapped scrap pieces of wood as spacer to create a tenon.
- The third layer is added without screws, so both pieces need to be glued.
- Put the layers together and clamp until the glue is dried.
- Use a jigsaw to reduce the height of one of the long stretchers. This will act as extra space for your legs when your sitting on a chair at the desk.
- Distribute your screws as evenly as possible.
- When adding the third layer with screws, make sure you don't put a screw in the same place as the previous layer.
- Try to spread your glue as evenly as possible.
Step 5: Construction - Frame Assemby
Once all frame parts are finished it's time for the assembly. The stretchers are assembled with only screws without glue for easy dis-assembly. Holes are pre-drilled in the side closest to the mortise as can be seen in the third picture.
The depth stretchers for the block are fastened using only four screws, which should be enough because they don't get any force. Small stretchers are used for the legs on the open side of the desk module so the mortises can still be used when necessary.
- Use a template of some sort to pre-drill the holes for assembling the stretchers. This way all the holes are exactly the same which makes it easy to change the modules.
Step 6: Construction - Top and Shelves
Once the frame is completed it's time to install the top and shelves. The shelves are pretty straight forward and are just screwed in place. The two tops need to be assembled in two steps. Because the top is meant to be replaceable it needs to be able to be (dis-)assembled fast and easy. So the bottom layer of the top is mounted first from above and is not meant to be removed from the table. The top two layers are mounted from the bottom such that no screws are visible but the top can still be removed relatively easy.
- The shelves are fastened using 3 screws each side.
- Holes are pre-drilled to prevent splitting. For the shelves this is important because they are screwed from the side.
- The bottom shelf can be put onto the lower stretcher while attaching it to the table.
- For the top shelf, use a spacer during mounting. Measure twice to make sure you pre-drill in the center of the plywood.
- The bottom piece of plywood for the tops are screwed from the top. Use at least one screw per leg and space some more screws evenly along the stretchers. (Can't find any pictures of how I screwed the bottom layer of the top.)
- Clamp the bottom piece while attaching it so the alignment with the legs is correct and doesn't shift during the mounting.
- Assemble the top two layers simultaneous.
- Screw both layers from the bottom using screws spread evenly over the top.
- Again clamp the two pieces to prevent them from shifting.
Step 7: Finishing
Not much to say about finishing this table. Depending on your choice of finish follow the instructions which came with it. I applied 5 layers of floor oil which gave it a nice protective finish.
While I was working on this workbench I came across this Instructable. So imediately I decided to put my initials on the bench. Since this was my first 'real' carving I'm pretty happy with how it turned out.
- Do the carving before applying a coat of finish.
Step 8: Finished Workbench
Once you worked your way through all the steps you can start using you bench. Put it in the place you want to put it. And well, if that doesn't work for you, just disassemble the modular piece and put it together another way and try some place else to put your new bench.
In the end I'm very pleased with how the workbench turned out. It's very sturdy and has enough mass to it. Also the modular idea turned out great. Before I settled with the way I mounted it now I changed it three times over. And it worked surprisingly well. I though that with the mass of the desk module it would take two persons for assembly, but I managed to do it all by myself without much trouble. Dis-assembly however does take two persons if you don't want the desk top to fall to the ground.
I still have some ideas to improve the workbench for my needs, but I summed those up in the next step.
Step 9: Additional Parts
I don't want to have my vise mounted to my bench all the time. So using pieces of scrap wood left over from my bench I made a plate on which I mounted my vise. The plate can be clamped to the workbench using clamps providing a solid grip.
The plate consist of two pieces of plywood glued together. In the bottom layer holes are drilled which can house the bolt heads. Holes through the top layer fastens the vise to the plate.
The mortise one of the two loose legs is filled with some 90 mm stroke left-over. In this piece a hole is drilled so the Ikea Tertial lamp can be mounted at that positions. Another of these left-over strokes will be added to the other loose leg. This way I can position a lamp on multiple positions on the table. The scrap piece is screwed from the 'wrong' side so no screws are visible in the carved initials. I'm also thinking about hacking the lamp stand so I can mount my camera on it or my girlfriend can mount her microphone on it. This way the table becomes more and more modular as planned.
The reason for the Tertial lamp is I already hacked one a couple years ago for my webcam after I saw this Instructable. See my comment on that Instructable for my version of it.
Since I like to make stuff and for many of the things I make I also like to make Instructables I'm often starting to miss a place where I can make good pictures of the things I make. From that a plan came to utilize the space between the shelves and the top of the block for a small foldable photo studio. This photo studio should become some kind of drawer which opens on top of the desk. Once on the desk it can be opened to form a white backdrop and again some holes should be present for the lighting (Tertial lamp) and the camera stand (also Tertial stand).
I haven't started this plan yet (and maybe never will), but some kind of drawer in that position can definitely be achieved and provide good storage space. That is if you are able to keep a clean desk.
As can be seen in the last image in the design step it is possible to mount a workbench vise to the table through one of the stretchers, creating a front vise. However it is also optional to make it as a module, making it an end vise. For me it will depend on whether or not I will make a drawer/photo studio. Since such a drawer would be in the way for a vise.