January, 2008

Building my workbench

I'm setting up a basic workshop in my basement, and my first priority is to build a workbench. I spent a fair bit of time researching the design - I wanted something that wasn't going to take forever to make, that I could build with the tools I had (I have a mitre saw, a router and a circular saw but no table saw as yet), and yet was going to provide a woodworking challenge, and adhere to some basic personal carpentry tenets (no nails, no screws into end-grain, etc), and of course I wanted the end result to be a functional, solid workbench that would be satisfying to use. The other requirement was that it had to be possible to disassemble.

To keep cost within reasonable limits, it's all pine. The frame is all 2x4s and 2x6s and I purchased two pre-laminated 2'x6'x3/4" boards for the bench top to save time. Depending on how rigid that turns out to be, I may end up adding another layer of something harder in the future.

After purchasing all the lumber and cutting it to length with the mitre saw, I glued and screwed the bench top together.

Once the top had dried, I placed it on top of an old desk that was gathering dust in the basement to use as a temporary work surface. I then began work on the two frames for the workbench sides. My design for these was to cut half-mortises into the sides of 2 2x4s and then glue them together to make a full through-mortis in the legs to receive tenons on the ends of the rails (also 2x4s).

I didn't take any pictures of this process unfortunately. I made many mistakes - one of which was trying to line up all eight leg pieces to route en masse using a single guide board. This turned out to be problematic since each of the legs was slightly different in thickness or warp so that the router did not travel completely square to each leg (because the router base spanned more than one 2x4). When I put the 2x4s together afterwards I had mortises that needed to be chiseled out square. I made a number of other measurement errors too which compounded my problems, but I managed to hide most of them.

One mistake I made in the photo above was clamping the frame with those long clamps without also clamping it to the table, which caused the weight of the opposing clamps to twist the frame by about 1/4" while the glue was setting. Once the stretchers are attached, I am hoping that will pull the frames square again.

I also screwed the legs together for good measure. Once the frames had fully set, I got a chance to see how they will look with the bench top (balanced on top).

The plan had been to brace the bench with an apron and stretchers on the front and back using 2x6's. Here you see the two apron pieces in position. These will be held by a hex-bolt with a hidden recess for the nut on the inside of the apron, allowing the bench to be disassembled later.

With the aprons and strestchers clamped in place, I drilled the bolt-holes through the legs and into the 2x6s. This got to be rather complicated because the wood had warped significantly during the months it has been stored in the basement, which meant that each hole had to be measured and calculated individually.

I cut a router template for the recess hole which provides access to the bolt-nut. The idea was to leave 1/4" of thickness on the outside of the strecther, but due to the warp in the wood and inaccuracies in centering the bolt-hole I found I had to go deeper for some stretchers which pushed the limits of my router bit. I didn't realize until afterwards that I was burning the shoulder of the wood by plunging the bit all the way up to the shank.

At this point I could bolt the rear apron to the legs using a wrench to hold the nut in place while I tightened the hex-bolt on the outside of the leg.

The two stretchers were bolted on in a similar fashion.

I have decided to drop the front apron because it doesn't allow me to attach the vise I have purchased very easily. I had originally expected the vise to have a smaller cross-section through the apron, but I ended up with a larger vise and with the spacer I will need to make it flush with the bench-top, it will extend about 5" below the bench, almost all the way through the apron.

I'm hoping that the rear apron will be sufficient for this thickness top to keep it supported. If not, I'll have to think about adding another layer to the top.

To attach the top, I screwed some cleats to the apron and then screwed up through the cleats into the benchtop.

I attempted to elongate the forward screw holes in the cleats to allow for some wood movement in the top, but it was only about 1/8" to each side which may not be sufficient.

The next challenge is attaching the vise. It's a cast-iron, 9" vise with an 11" opening and a quick release. I plan on adding hardwood cheeks to the jaws and setting the inside cheek flush with the bench.

I think I would buy a different vise if I had the chance again. This one doesnt have a square corner anywhere on it. The inner jaw tilts forwards, is 1/16" thicker on one side vs the other and with the mounting flanges flat against the workbench the jaw is higher on one side by 1/16". So fitting it precisely into my bench required hours of fine-tuning.

The vise has a rather large amount of toe-in, probably more than it should. So I may end up having to reshape the cheek on the outside jaw at some point. I'll wait to see how well things work as is before attempting that.

With the vise installed, I can really start using the bench which is a big leap forward.

The next step is to fit a shelf across the lower stretchers to provide storage and a little additional rigidity to the frame of the bench. The shelf is 3/4" poplar plywood, and I plan to add a similar piece of plywood to the back of the bench for vertical rigidity.

I made another mistake at this stage, measuring and cutting the shelf to size one day taking into account the thickness of the back plywood panel, and then returning a few days later to notch out the corners to fit the legs and placing the shelf flush with the rear legs.

So unfortunately, that means the front of the shelf doesnt overhang the front strether the way it should. However, I was planning on edging the plywood anyway, so now I will use a thicker piece to edge the front of the shelf to extend it forward.

Here's a shot of the bench with the trim glued on and the shelf screwed down.

I have also been playing around with Google SketchUp which is a great tool for drawing up plans. Here's a snapshot of my workbench in SketchUp as completed so far, which you can click on to download the SketchUp project if you have that installed.