In:In the Shop

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With the base pretty well buttoned up, it’s time to move onto the top.  The construction isn’t too tricky, but there are a few details to be aware of in order to avoid a catastrophe.  So let’s get into it.

Start by gluing up some 8/4 stock into a panel that’s about 14″ wide by however-long-your-bench-is… in my case it was 48″.  That will act as the main surface.  You will also need an 8/4 board ~5.5″ wide to act as the front apron of the bench.  Now prep the two end rails which are 1″ thick x 20″ long x 8/4″ wide (to match the bench thickness).  Finally, the rear rail is 3/4″ thick x 48″ long x 8/4″ wide.

Main bench top surface getting glued up.

When all the components are prepped to size, flat, and square, you have a choice to make: you can either move onto the bench assembly and add the dog holes later on or add them now.  Adding them now (which is what I did) is easier as the components are still manageable on a drill press, but you need to make sure your layout is precise relative to the location of the legs on your base.  Otherwise, you may have holes that get blocked which make them useless and looks sloppy.  So plan ahead and be careful.  If you wait until everything is assembled, you can virtually guarantee you’ll clear all the base components, but it takes more effort to ensure the holes are perpendicular depending on your methodology for drilling large holes without a drill press.  It’s your call, do whatever you feel most comfortable with.  Regardless of when you drill them, add hefty chamfers around the holes so they don’t blow out when you’re flattening the bench top.

Components getting prepped and drilled, nearly ready for assembly.

The next step is fitting the end rails to the top surface.  There’s a few things going on here, so bare with me.  First, it’s going to be a breadboard-style end cap, meaning part of the bench top gets milled off each end to create a full width tenon.  A matching groove gets placed in the end rail, but the rails extend beyond the back of the main surface to capture the rear rail, so it has to be a stopped groove.  This helps keep the bench top flat (which is the whole reason breadboard ends are used in table construction), but also provides a method of attaching the end rails to the bench so that they can reach to the back of the bench and secure the rear rail.  Additionally, there is a dovetail feature cut into the front 1″ or so of the bench top tenon and again, this gets a mating feature cut out of the front of the end rails.  The dovetail needs to be just slightly larger than the breadboard tenon in order for things to assemble properly.  This feature gets repeated in the back of the end rails as a means of attaching the rear rail.  This all sounds a bit confusing to read, but you can check out a drawing of the end rails and review the pictures below to help fill in the blanks.

Cut the breadboard tenon short, leaving material for the larger dovetail key at the front face. Lay out the dovetail and cut it out by hand.

Run the groove through the end rail to match the breadboard tenon, slide it over the tenon and butt it up against the back of the dovetail key. Then transfer the dovetail over to the end rail and cut it out like you would for any other half-blind dovetail. Repeat this process in a similar fashion for the rear rail (shown here) by cutting the tail on the rear rail first, then transferring it to the end rails.

Chiseling out the remaining waste in the dovetail socket.

When the bench top, end rails, and rear rail are finished, there’s one more detail to discuss… glue.  You can’t simply glue everything together because the top needs to be able to expand and contract and gluing the end rail directly to the top will prevent that, leading to self-destruction.  So dry-fit the end rails onto the bench and clamp them tight against the top so there are no gaps where they meet the bench top.  Drill 1/4″ holes through the bottom surface of the end rails every 2″-3″, but stop them a little short of piercing through the top. (You can drill them straight through, but then you’ll see them on the top surface and I chose to leave them hidden, but it’s just a cosmetic choice, so it’s your call).  The holes should be centered on the tenon.  Next, remove the end rails and file the 1/4″ holes in the tenon into 1/2″ slots.  Now you’re ready for assembly.  Start by gluing the end rails to the top, but only use glue on the dovetail key.  This will lock the front edge in place (more on that later) and all the expansion will shift the bench towards the back.  Then drive 1/4″ dowels through the holes to pin the breadboard end to the top.  Because you added the slots in the tenon the top can slide as necessary while still keeping the end rails tight.  No glue should be used anywhere in the breadboard tenon area.  Don’t even use glue for the 1/4″ pegs until they’re almost completely seated.  A bit of glue in the final 1/4″ or so will keep them from backing out while preventing glue from getting in the joint itself.  Now you can glue in the rear rail and when its dry, flatten everything so you’re left with a 20″ x 48″ bench top with a rectangular hole in the back.

Completed breadboard end rail with dovetail key.

Adding chamfers.

The final step is to glue on the apron. Remember that we put glue in the dovetail key, so the front edge of the bench is treated as our stationary datum.  wood expansion is going to move away from that corner, so it’s perfectly acceptable to glue the apron on over the entire length of the bench, including the overlapping cross-grain in the corners of the end rails.

Front apron glue up.

After the glue dries, make sure the apron is flat and square to the bench top surface.

Final bench top with finish applied.

With the top complete, all that remains is adding the 1/2″ thick bottom panel for the tool tray.  Nothing special here, it just gets screwed into the bottom of the bench surface.  This is preferable to capturing it in a groove because the bench is only ~1.8″ thick after milling, so it’s not a terribly deep tool tray.  Trapping the bottom surface in a groove would only reduce this depth further and it would be impossible to replace the panel should it ever get cracked or otherwise damaged.

Laying out the bottom panel. You can also see the location of the breadboard pegs running through the underside of the bench.

Pre-drilling all the screw holes to secure the bottom panel.

And that does it for the top.  In the final blog entry I’ll cover the vise chop and hardware installation, assembling all the components, and painting the base.


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