 Build a Simple Planktop Workbench
Build it in a weekend — use it for a lifetime. We used inexpensive construction lumber for the entire project, but made it rugged enough to stand up to hammering, sawing, and grinding. We also installed a machinist's vise on the top. The end assemblies of the bench are strong and sturdy. A pair of large, square legs are joined to three rails with mortise and tenon joints. But apart from the solid construction, the interesting thing about this bench is the way we went about making the mortises for the rails.
Instead of drilling or chopping out the mortises, I cut them out on the table saw. Sounds impossible? Let me explain. Each leg is glued up out of two separate pieces. But instead of making the mortises after the legs were glued up, I cut dadoes on the inside face of both halves of the leg beforehand. This way, you end up with perfectly sized mortises once the legs are glued up.
Making the Bench Legs
To make the legs, you can start by cutting out eight blanks from 1-1/2"-thick stock for the leg halves. I cut these blanks to exact length, but I made them a little wider than necessary so that I could plane the legs down to finished width (3") after they were glued up. When you've finished cutting all the blanks, you can go ahead and cut the dadoes that will make up the mortises. I used the rip fence as a stop when cutting the dadoes to ensure that each pair of dadoes would line up when gluing the leg blanks together.
Through Tenons
A few cuts on the table saw are all it takes to make perfectly sized mortises for the through tenons of the bench. When it comes to gluing up the leg halves, the trick is keeping all the dadoes aligned while you're clamping the pieces together. To do this, I used some wood "keys." I simply cut some blocks of hardwood to fit in the mortises in the legs. Then I chamfered the edges and rubbed paraffin wax on the surfaces of the keys so they wouldn't get glued to the legs. After the glue is dry, you can remove the clamps and the keys and square up the legs by planing them down to their finished width.
Half Laps – Before moving on to making the end rails, there are a couple of things left to do on the legs. First, you'll need to cut a couple of half laps on one face of each leg to hold the stretchers that will be added later. The rip fence can be used as a stop to position these half laps, just as you did when cutting the dadoes for the mortises. Next I routed a chamfer on the edges and the bottom of each leg.
Rails – With the legs complete, the next step is to add the end rails. At first glance, these rails look identical. But if you take a closer look, you'll see that there are some slight differences. For one thing, the upper rails are slightly narrower than the lower and middle rails. And the middle rails have through tenons that stand proud of the legs while the tenons on the upper and lower rails are shorter so they end up flush with the half laps. Don't let all this confuse you though. To make things a little simpler, I started off by cutting all the blanks for the rails to the same length Waxed hardwood "keys" keep the two halves of the leg aligned during glue up. This allowed me to cut identical length tenons on the ends of all the rails.
Before assembling the rails and legs, I chamfered the ends of the tenons on the middle rails using a router and a file. Then you can trim the tenons on the upper and lower rails to length. Once this is done, all you have to do is rout a chamfer on the edges of the rails (except for the top edges of the upper rails). Now you can glue up the end assemblies, making sure to check each one for square.
Materials & Hardware
- Legs (4) 3 x 3 - 34-1/2
- Upper End Rails (2) 1-1/2 x 4 - 22
- Middle End Rails (2) 1-1/2 x 5 - 23-3/8
- Lower End Rails (2) 1-1/2 x 5 - 22
- Upper Stretchers (2) 1-1/2 x 4 - 90
- Lower Stretchers (2) 1-1/2 x 5 - 90
- Cross Rails (3) 1-1/2 x 4 - 21
- Front/Back Cleats (2) 3/4 x 1-1/2 - 82]
- End Cleats (2) 3/4 x 1-1/2 - 17
- Slats (15) 3/4 x 51/2 - 21
- Top Planks (3) 11/2 x 9 - 95
- (74) #8 x 2" Fh Woodscrews
- (30) #8 x 3" Fh Woodscrews
Stretchers – The stretchers fit into the half laps that you cut earlier on the legs. Half laps are also cut in the stretchers, creating a solid, interlocking joint. In order to get a good fit, start by sizing the width of the upper and lower stretchers to match the half laps in the legs of the bench. Once you've got the stretchers cut to size, you can cut the half laps. I did this with a dado blade on the table saw, using the rip fence as a stop to position the ends of the half laps. The stretchers are pretty long, so you may want to use an outrigger stand next to your table saw to help support them. After chamfering the edges and ends of the stretchers, you can clamp the stretchers to the ends of the bench and drill pilot holes for the screws. I used some large, construction lag screws for attaching the stretchers. These screws are not only strong, but they have a tough, rugged appearance that matches the overall look of the bench.
Cross Rails – To help support the top of the bench, I added three cross rails between the two upper stretchers. These cross rails are simply cut to length and then screwed in place. Once you have the two end assemblies complete, building the rest of the workbench really goes along pretty quickly. The ends are connected with two pairs of stretchers — one at the top and one near the bottom of the legs. These stretchers serve a dual purpose. The upper stretchers help to support the top of the bench and the lower stretchers support a shelf.
Lag Screws - Use heavy-duty, construction lag screws to attach the stretchers to the ends and cross rails.
Shelf – To create some storage space under the benchtop, I added a shelf to the lower stretchers and rails. The shelf is really just a series of slats that are supported by cleats attached to the inside faces of the lower stretchers and rails. You can start by cutting the cleats to size and screwing them in place. The goal here is to position the cleats so the slats will end up flush with the top edges of the lower stretchers and rails.
To make this easier, I built a quick positioning guide for installing the cleats. All I did was cut a small block from the same stock that I used for the shelf slats. Then I fastened this to a wider piece of wood. With the guide clamped in place, all you have to do is butt the cleat up to the bottom of the guide and screw it in place. Figures 8 and 8a show you what I'm talking about. Once the cleats are in place, you can cut the 15 shelf slats to identical size. After chamfering the edges of the slats, I set them in place on the cleats. Start at the center of the bench and work your way out to the ends, leaving a 1/8" gap between each slat.
When you reach the ends, you'll have to trim the end slats to width and notch the corners so they fit around the legs of the bench. Once this is done and the slats are fitted into position, you can go ahead and screw each slat in place. Top – At this point, the only thing left to do to complete the bench is to add the top. To avoid the time and hassle involved in making a glued-up top, I used three separate planks. These are just cut to size and then the top edges are chamfered. |
