When I left off in my last post, I had installed a tongue and groove shelf in the bottom of the stretchers on my workbench base. When I made the stretchers, I included a ¾” x¾” rabbet on the inside top edge. This was intended to hold a shelf/lid that would be hinged on one side. This lid will measure approximately 47″ x 27″, so I figured that making it as a frame and panel assembly would allow for wood movement without it jamming in the rabbets.
I got my inspiration for this frame a panel lid from the front cover of Christopher Schwarz’ Workbench Design Book. Take a look at that link and you’ll see what I mean. I’m changing the design a little for mine, and will have a third (center) rail and two floating panels instead of just one larger panel. And because I’m a idiot, glutton for punishment, masochist, etc. etc., I’m going to assemble it with wedged through mortise and tenon joinery. I may yet regret this, we’ll see.
Since I made the workbench top out of douglas fir and sapele, I considered making the frame of sapele and the panel of douglas fir. My plan has been to use material for the frame that will finish out at 1″ thick (or just over) and I went to my lumber rack to look for some suitable sapele. Unfortunately, all of the thick stuff was about 1 7/8″, too thin to resaw in half and get two usable pieces and I didn’t want to give that much nice wood to the planer to thin it down.
I went back to my pile of douglas fir, and was able to easily find some suitable wood for the frame. I found an 8-foot length that would make both of the stiles, and I clamped it to my workbench to cross-cut it to rough length.
I also found three suitable pieces for the rails. I set a marking gauge to 1 ¼” and marked a reference line for resawing. This will give me plenty of wiggle room in case my resawing doesn’t go well. I’ll finish thicknessing at the planer.
I set-up my usual makeshift fence on the bandsaw and cut the rails and stiles.
I then fed all the parts through my planer to clean up the bandsaw marks and ensure a consistent thickness. The stiles are about 4″ wide and the rails are about 3″. All of them finished up just a hair under 1 1/8″ thick.
I laid out all of the parts and moved, flipped, and rotated them until I felt that I had them arranged for best appearance.
I had been looking forward to laying out and chopping the mortises with some of the vintage tools that I have been collecting and restoring for the past two years or more. I have a 3/8″ English mortising chisel by Isaac Greaves that would be perfect for this job.
I adjusted the pins in my mortise gauge to match the width of the chisel. I then adjusted the face to the correct distance from the pins that the gauge would mark the same two lines from either side of the work piece. This ensures that the mortise is centered.
Each stile has 3 through mortises, but they have to be chopped in halfway from each side. This means that I spent some time carefully laying out all 12 mortise locations.
Once all the layout was done and tipple checked, I started chopping. At first it went quite smoothly, but the stiles as I mentioned are 4″ wide. It takes a little while to chop down two inches from either side.
The other problem that I ran into was in clearing out the chips. If you leaver them out with the chisel, then you crush the edge of the mortise. On the inside surface that is going to be covered by the shoulder of the tenon, this is not so important. However, with through mortise and tenons, I need to keep to my exterior layout lines crisp, or it is going to look like crap when I’m done. I found I had to stop periodically to clear out the chips with a screwdriver. I did less damage to the edges this way.
I chopped halfway in from one side, then flipped the piece over and repeated the cut. Finally, I connected the two mortises into one. It was a little rough looking inside though.
To clean up the walls of the mortise, I turned to two more garage sale found tools. A rasp and a float.
I lightly cleaned up the walls of the mortise. I did not want to remove much wood here as it will affect the fit later.
I now have a deeper understanding of why the hollow chisel mortising machine was invented. These six through mortises took me at least 4 hours to cut. My whole day in the shop was spent doing nothing but this. I think that if the mortises were only 2 inches deep and weren’t through mortises, things would go much quicker. I wont go so far as to say that I wouldn’t cut mortises like this again, but by the fourth hour of pounding away with the mallet, I was rather sick of it. The first one or two were fun, by the last two it had become a chore.
The next thing that the stiles need is a groove to hold the floating panels. I decided upon a panel thickness of 5/8″, so set-up a dado stack of that width in the table saw.
Setting the fence was a little tricky, and I had to do a couple of test cuts to make sure that I was centering the 5/8″ groove on the stiles. Flipping the work piece around and running it through a second time will center the cut, but it likely wont will be 5/8″ wide unless the time is taken for careful set-up.
With the fence properly adjusted, I added some feather boards to keep the stile pressed firmly against the fence while making the cut.
I made one pass, flipped the stile around and repeated the cut. I checked it and found the groove to still be 5/8″ wide. Perfect so far. I had only cut the groove 3/8″ deep on the first two passes. On the next passes, I raised the blade to take the groove to its final depth of 3/4″
That’s it for the stiles. Now I need to make the rails.
I laid out the shoulder lines on all three rails with a knife and square. I then chiseled a notch on he waste or tenon side of each line. These lines should help to keep my shoulders crisp and joints tight.
At the base of each tenon, I will need a 5/8″ thick stub tenon that is 3/4″ long. This will fill the 5/8″ groove in the stiles. The remainder of the tenon will have to be 3/8″ thick to match the mortises. I raised & lowered the dado head and made some test cuts in the waste area of a rail. I adjusted the height until I was left with a 5/8″ tenon.
I tested the fit of the stub tenon in the stile groove.
I then made a cut on the table saw as close to the notched knife line as I could get with out touching it. I did this from both sides.
I made a second pass to widen the dado as the stub tenon will need to be 3/4″ long.
There is a very small bit of wood left on each tenon shoulder that needs to be removed with a chisel. I know this seems like an extra step, but I did it this way, so that my tenon shoulder is cut exactly on my knife line and I avoid over cutting the shoulder line with the dado blade. This should prevent having a gap when the joint goes together.
With the shoulders cleaned up, I needed to mark the tenons at the point that they will transition from 5/8″ thick down to only 3/8″ thick. I first marked the edges 3/4″ from my original shoulder lay out line.
I then struck a line across the face of the tenons, connecting the two edge lines. Again, I chiseled a notch into the waste or thinner tenon side of the line.
I repeated this process for all six tenons.
Back at the table saw I raised the dado blade and made test cuts in the waste until I was left with a 3/8″ thick tenon.
I compared this to the chisel that I used to chop the mortises and also to the mortises themselves.
Again, I cut close to my intended shoulder line, leaving just a hair for chisel clean up. I then made repeated passes along the tenon to remove all the excess wood.
They need a little clean up still, and the tenons have to be cut to width, but this was as far as I managed to get today.
I never thought that making a single frame and panel lid would take so long. I’ve been at this for a few days now and haven’t even started resawing any wood to glue-up some panels. I’m guessing this is going to be a couple of weeks project by the time I get it made, planed, and the hinges mortised in. I know… maybe I’ll complicate it some more just for fun, I could add draw bore pegs to the joints. Can you draw bore and wedge the same through mortise and tenon?
– Jonathan White