Preparing for the Drawer Blades

It had been my intention to post the carcase with completed draw blades – this would have been the next stage in any cabinet with straight sides. However it became increasingly apparent that, as a result of the many curves, this build is a tad more complicated, and I am have been left wondering whether I would ever get to be in a position to build the drawer blades as something else kept cropping up! It was a case of “I’d better to this before I get to that as it will not be possible later. And on and on ..

We left off a couple of weeks ago with frame-and-panel sides completed (for the second time!).

Before the drawer blades can be added, the carcase needs to be completed to position the blades in the horizontal. The carcase needs to be in its final dimension; it cannot be just held together at the rear with bracing, as currently.

It is possible – and indeed I like to hear the opinion of others here – that the sliding dovetails for the drawer blades could be marked and formed from inside the completed carcase. I am now seriously considering this method. Alternately, the carcase would need to be assembled and dis-assembled repeatedly for work to be checked, carried out, and then checked again. The latter will cause wear on the joinery, with resulting loss of tautness and accuracy.

The steps taken in this chapter include:

Making the upper front-and-rear rails, and dovetailing them into the legs.
Calculating the curve for the front rail, which will be the same curve for the drawers and the lower front rail.
Making the lower front-and-rear rails, and dovetailing them into the legs.
Shape the front lower rail.

In addition:

Initial preparation of the drawer fronts.
Rebating the rear of the carcase for the rear panel (another frame and panel).
Shaping a panel and rebating for a hidden drawer (that will fit inside the upper rails.

Below you see the front top rail with dovetails at each end. The rear top rail is identical. The depth of the dovetail is 6mm with a 1:5 ratio. It is kept shallow so as to avoid the mortice-and-tenon in the leg, wider and a lower angle to maximize strength and grip.

There appears nothing complicated about this. The sockets are chopped out and the right side is fitted …

It is only when I come to insert the left side that it dawned upon me that the corners are not square. There is a little more curve to the sides at the top than I intended, and now the legs will splay out if the dovetails are not modified to match the curve.

The amount to remove is about 1or 2 degrees, but it is a wake up call that this build is about joinery on the curve, and every joint will require individual measurement and fitting.

The final fit is pleasing. The upper front rail is still not completed. It will receive a curved face to match the curve of the drawers. Since this curve is followed also by the lower front rail and by the moulding at the top of the cabinet, calculating the curve now takes centre stage.

Above are the Jarrah boards for the drawer fronts. These have been thicknessed to 44mm, which is the maximum that could be obtained.

The curve was calculated by using the longest drawer and working on an even 22mm thickness. (The reason why I have chosen to bandsaw from solid and not laminate is that I believe that the bandsaw curve will be more reliable, that is, not be susceptible to springback as a lamination will).

Above: Drawing in the curve. I must admit that I just played with different thicknesses until I found a curve that looked right.

The curve was reproduced on 3mm MDF sheet, and two templates created, each for the same half of the curve. One is for inside the line, and the other the outside. These will enable the same curve to be plotted from the centre of each board.

The other template made was for the shaping of the front and rear lower rails.

Above: the curve of the lower rail. This now needs to be dovetailed inside the legs.

Checking the angle inside the base of the legs. This will be transferred to the lower rails. (Note that the undersides of the legs have been rasped to sit flush with the floor).

Above: the front upper rail receives a lamination of the curve.

Sawing the sliding dovetails is essentially the same as sawing a tenon. The angle used is 1:5 once again. These are parallel sliding dovetails – rather than tapered – since the sockets are only 50mm (2”) in length.

Shoulders are pared flat.

Tuning of the dovetail shoulders can be done with a chisel or a side rabbet plane. I converted this Stanley #79 to trim the male and female angles of sliding dovetails. This one has a fence suited to 1:7, which is what I typically use. The present 1:5 was chosen as the dovetail tongue is only 6mm high to avoid breaking into the mortice (used for the panel rail), and this would create maximum grip.

The tongue is 50 mm long, and sawn short to end in line with the drawbore pin. This way half of the mortice-and-tenon join is not weakened in any way.

Above: The front- and rear rails. The cut outs will be shaped after the fitting to the mating socket in the legs.

Time to chisel out the female sockets.

Mark the width of the base of the dovetail …

… and transfer this to the leg.

Saw to the depth of the socket. This is no different from a half-blind socket in a drawer face.

One alternative method would be to first chisel out the end of the socket to create a space for the saw to be used along its length. I did not consider this here out of concern that I might chop too deeply and damage the mortice below.

Chop into the waste to ease its removal (as one would a hinge mortice).

Shoot it out with a chisel. Repeat until you get close to depth.

Clean out and level the floor with a router plane.

I build this guide for chiseling the sidewalls to 1:5. However I found it unnecessary after the first socket. The short length of 50mm made it relatively straight forward to just use the sawn front section as a guide for the chisel to remove the waste freehand.

Three of the sliding dovetails fitted well with minor paring. The fourth needed a little thickness added. As with a too-thin tenon, glue on a veneer to the cheek, and then pare to final thickness.

That’s where it was at the end of last weekend. This weekend I started on parts that I needed to complete before I could go further. It felt like this was jumping several steps ahead, but it was not possible to determine measurements – in particular the size of rebates to the rear of the cabinet (for the rear panel) until the panel was designed and sized.

This weekend dawned with more time available than last weekend. On Saturday I completed re-sawing, planing and gluing up a large panel for the rear of the cabinet, a small panel for a secret drawer, and frames for the rear panel …

Below you can see the extend of the camber to the drawer fronts, from the front- and rear rails (the rear rails are straight). The camber is mild-moderate – just enough to soften the face and to add to the lines, and not enough to overdo the curves. Well, that’s what I think .

Below: the panel for the secret compartment, and the rails for the rear panel ..

Saturday the plough was needed ..

Much of the work on Sunday involved rebates – rebates internally for the secret panel, and externally for the rear panel.

Below: using a sticking board to hold the rails when rebating ..

The piece below required rebates to each side …

Below: part of the rear panel frame sitting in a rebate in the upper rail ..

… and another in the lower rail ..

Then the side rails required being grooved for the secret compartment’s panel …

The groove could not extend the full width of the panel as it would have run into the mortice-and-tenon.

Below: the panel is notched at the corners. The sides have space for expansion into a rebate (to be attached with screws in elongated holes), while the ends fit in grooves ..

Turning now to the lower rails. These need to have the cutout shaped.

Notice that the cutout cannot be taken to the ends as a fillet is required to hide the sliding dovetail.

The waste for the curved underside is removed on the bandsaw, and then cleaned up with rasps and cabinet (card) scraper.

The front edge of the fillet is shaped into a fine angled curve to reduce its impact. The rear edge is left square for added strength.

At the rear is the front lower rail, and at the front is the upper rear rail. Got that, didn’t ya! 

The cabinet is currently together as a dry fit. Above is the lower, front rail.

Above: on the left you should just make out the curve of the lower front rail, and on the right the curve of the upper front rail.

Where the project now stands …

Regards from Perth

Derek

July 2015