This post is a follow on to yesterday’s in which I milled and cut all the boards for the shelf that will go in the bottom of my workbench. At this point, all of my boards are over length and need to be cut down to fit into the space between the stretchers. There is no need to measure here, I will mark the lengths directly off the workbench base.
Since the stretchers are not as thick as the legs, the two end boards of the shelf will need to be notched to fit around the legs. I will start with these two boards first. When cutting the tongue and grooves, I left the tongue off two boards to use for this purpose.
The groove that I cut into the stretchers is 3/8″ wide and a little over 5/8″ deep. To start the fitting process, I need to cut a 3/8″ deep by 5/8″ wide rabbet into one end of the shelf board.
For the two end boards only, I also had to cut the same 5/8″ rabbet into one edge of the board. This will create a tongue that will fit into the groove in the short stretchers.
The 5/8″ rabbet cut into the end of the board, creates a 5/8″ tongue that fits into the groove on the front stretcher. I pushed this tongue all the way in to full depth.
The other end of the board was passing below the opposite stretcher. Using a marking knife, I marked a line indicating the final length.
Once the board was cut to length, I tested it to make sure it would fit. To install the board I need to create a rabbet on the other end. This rabbet does not need to be as wide as the first. If it was, when pushed in to depth, the first end would fall out. I cut this second rabbet approximately 3/8″ square.
To install the board, I pushed the 5/8″ tongue all the way in, raised the other end to align the 3/8″ tongue with the other groove, and slide the board into the other groove. The board is now held in place at both ends.
I need to notch these two end boards to fit around the legs. This will allow the 5/8″ tongue that I created on the edge of these two boards to seat into the short stretchers. Again, no measuring here, I installed the board and marked the location of the legs directly. This gave me the width of the notches. For the depth, I did measure, from the inside edge of the leg, to the bottom of the groove. I subtracted a 1/16th to make sure that the tongue didn’t bottom out in the groove and leave a gap around the legs.
With the boards marked, it was a simple matter of cutting to the line. I stayed just a hair off the line on the waste side and used a chisel to pare exactly to the line.
Here is one of the end boards cut and ready for installation.
It was a fairly tight fit and I used a mallet and a scrap block of wood to tap the board home. It’s not coming out of there now even if I wanted it to.
I repeated this process and fit the end board at the other end of the workbench base. I then continued to fit the tongue and grooved boards one by one to fill up the remaining space.
The boards that make up this shelf are only held at either end and they are only 6 inches wide. If a heavy enough weight was placed on them, they could bow downwards. This is why I took the time to cut the tongue and grove joinery on all of the boards. A weight placed on one board is transferred to the adjoining boards via the tongue and groove joints. This has the effect of making the shelf distribute loads almost as tought it were a single wide board.
The other added benefit of the tongue and groove joinery is that should the boards shrink, instead of opening gaps to the floor, the gap will only reveal the tongue ¼” below the surface of the board.
As I continued to add each board, I fine tuned the fit with my Veritas Shoulder Plane. A couple of times I had to adjust the tongue so that it would more easily slide into its corresponding groove, and a few times I had to deepen the rabbets on the ends a little so that they would slide along as needed. I only did this a little and only when absolutely needed. I didn’t want the boards to fit loosely in the groove as I am hoping that a tight fit will help to keep the boards flat and reduce any future cupping.
As I continued to fit each board, I worked out a quick method for cutting the rabbets. I set up a sacrificial fence that would give me the full 5/8″ rabbet. I clamped a piece of ¼” scrap to the fence in such a position that I could rotate it up out of the way when cutting the full rabbets. When pushed down, and used as a guide for the work-piece, I’m left with a 3/8″ rabbet. This is much easier than repeatedly adjusting the fence.
I continued to add the tongue and grooved boards until I was left with just this gap. Because of the way that I have installed the boards, there is no way to tongue and groove a board into the remaining space. I don’t anticipate it being a problem as it is only a very small area of the shelf.
To fit a board to this gap, I held up my last remaining board from underneath and marked it with a knife.
I ripped the board to width with a handsaw making sure to leave it a little larger than needed.
I clamped the board on edge in some hand-screws and planed down to the line. I checked the fit and planed a little more.
This is what I love about handtools. There is no better way of custom fitting a part like this than sneaking up on a perfect fit with a well tuned plane. A few thousandths of an inch off with each pass and it ends up fitting like a glove. A table saw could cut the board to width, but it can only be done easily if the needed piece is supposed to be perfectly parallel. What if it tapers? With a handsaw and a plane, you simply cut leaving the line and finesse the fit with a few shavings.
With the last board cut to width, all that remained was to cut it to length and cut the 3/8″ rabbet.
The last piece slid home beautifully.
So here it is:
I’m very pleased with how this turned out. I think the tongue and groove joints were time and effort well spent. The shelf is surprisingly rigid. If the wood shrinks, any gaps should be minor and somewhat hidden by the tongues. If the wood swells… well OK, I haven’t really allowed for that, but I hardly think it would be able to break the joinery between the legs and stretchers, those are some massive pegged joints. I have said all along that I don’t anticipate too much wood movement on this bench. The wood has been drying in my shop for two years and the bench is going to stay right here in the same shop. The weather here is fairly humid year round, so I’m not anticipating much movement due to seasonal changes. Let’s hope I don’t have to eat those words later.
Next I’m going to make a frame and panel lid to fit atop the stretchers.
– Jonathan White
Pingback: A Frame and Panel Lid for the Workbench Base - Part 1 | The Bench Blog