Monday 9 July 2018
For some time I had been hoping that someone would commission me to make a desk. Desks are great to make because they incorporate lots of detailed cabinet making and, if the budget of the client will allow it, they present an opportunity to go all out with bells, whistles and dovetails.
My wish came true a few months ago when I was asked to take over the project by a fellow maker who was having to give up his business due to a back injury. The traditional pedestal desk had to be constructed from timber milled from an oak tree which fell some years ago. The timber was already seasoned, and most had been used for oak panelling in the study where the desk, a 25th wedding anniversary present, was to be placed.
While making the desk, I realised that there were some key areas of interest surrounding this design, and I thought it would be worth writing this article to explain some of my findings and methods in case they could be of use, so I have taken detailed looks at the pedestal carcass design and construction, the incorporation of metal runners into a traditional desk design and classic dovetailing with a router.
This piece is now in situ and the couple is delighted with it. I am particularly pleased with the outcome of various new techniques used to create it and feel that they have been successful.
I estimated around 200 hours for making the desk and I must admit that I overran by around 15%, but I feel that the result was worth the extra effort.
I do, however, think the design would have benefited from having a graduated set of drawers on either side rather than filing drawers, but due to the specification this was not possible.
The specification included a keyboard drawer, made to look like a normal centre frieze drawer, filing drawers to support hanging files, and two deep drawers for storage.
The overall size of the desk was dictated by the room, and by a chair that was intended to go with the desk. I was asked to use traditional cabinet-making techniques to create a desk with a rustic country feel, and the client stipulated the inclusion of many timber features like knots and even defects that I would normally discard.
The desk was to have initials carved into the top.
Due to its size construction was done in several parts. The two pedestals, both with a plinth attached, are joined to a central modesty board which also has a piece of plinth attached to correspond to the pedestals left and right.
Once these three pieces are assembled, the top carcass can be placed on top, with a decorative moulding overhang, for location and to help hide the join. This carcass has the top secured to it, and once in place, all the pieces are screwed together from inside to give the appearance of a solid piece of furniture.
Frame-and-panel construction enabled me to choose wood with interesting grain for the panel components. The two pedestals, apart from being left and right, are identical, both containing a deep drawer for storage and a filing drawer at the bottom.
The top carcass is constructed using a series of runners and kickers, all encased around the outside with rails that follow the lines of the pedestal frame.
Drawers & top
The two drawers left and right of the top carcass are intended for stationery and pens etc. The central drawer is designed to hold a wireless keyboard. This drawer is on runners to enable the keyboard to be used on the drawer surface or lifted out and placed on the desk.
The desktop is made of three boards glued together and cleated on the ends to aid timber stability. The central board is split into three and the middle piece has initials carved into it.
The desktop is attached to the top carcass, with allowance made for timber expansion or shrinkage.
To make the most of the oak, I felt that it was best to use it to make the desktop and buy in timber for the rest of the job, as there was not much left over from the oak panelling project.
The desk is finished with Osmo Polyx hard wax oil.
Frame and panel carcass construction
The pedestals are made up of two sides with two panels in each, and a back with one panel. These three parts are held together with three dust panels separating the filing drawer at the bottom and the deep storage drawer at the top.
The dust panels are made up of an oak frame with a veneered oak panel in the centre. The show frames, sides and back, are constructed with an oak frame and captive characterful oak panel within.
Firstly, I selected the wood for my panels by finding the defects, knots and other points of interest and drawing around them with templates. I made one for each different-sized panel according to its position within the desk. These panels were then cut out and machined up, before I fielded them on my spindle moulder. The frame components were selected from a prime board, as this level of quality is more reliable for this.
I used a network of stub tenon and grooves to slot the individual frames together. This enabled me to run all the grooves through, and making the grooves deeper than normal provided enough gluing surface for strong stub tenons. This saves a lot of time with mortice & tenons which in this situation are unnecessary.
By doing the majority of jointing for the pedestal this way, everything can be machined together with the same setups. The setups were also the same for the dust panels. This saves time and produces the same result as full mortice & tenons, as long as you plan carefully and machine accurately. The running order for this process is as follows:
1. Machine panels
2. Machine frame components to size and leave over length
3. Run the grooves in all components, with muntins on both sides
4. Cut all components to length allowing extra length on rails and muntins for tenons
5. Cut stub tenons on the end of cross rails and muntins
6. Dry assemble with panels in place
7. Glue up and check for square
Use this order and you will find, as I did, that the frames come together very quickly. I also machined some spares in case any components were damaged.
The assembled frames are biscuited together to form the carcass.
Metal runners and slides
There are many types of runner available for all sorts of applications. To make this project I have used two different types, a pair of full-extension drawer slides for the keyboard drawer and two pairs of Blum tandem runners for the filing drawers.
These runners are for side mounting and under mounting. They come in a range of lengths with the optional positive in and out stops which can be removed or adjusted by paring away at the rubber pad.
Because they are only 12.5mm thick they are ideal for use in smaller or more delicate applications. They do have a load capacity, as most runners do and, as you might expect, this type of runner is stronger when side mounted rather than under mounted, although heavy-duty ones are also available.
Blum tandem runners
These runners are the ideal choice for wooden drawers or pull-out surfaces. Very versatile, they are mounted inside the carcass and secured to the drawer box on the underside so are hidden from view.
This type of runner comes with or without Blumotion which is the soft-close mechanism much appreciated by clients.
These tandem runners come in pairs, left and right, and you must also buy the locking clips, supplied separately, which secure the drawer box and allow easy removal of drawer box from carcass, and height adjustment, which is the other positive regarding these runners.
They can be adjusted, up and down and in pitch, very useful for getting the gaps around a drawer spot on.
The keyboard drawer comprises a pullout tray with short sides and a back. The hinged drawer comprises a pullout tray with short sides and a back. The hinged drawer front gives the appearance of a drawer when closed, but folds down, once opened, to give a usable surface for typing on. I used the drawer slides for this because there was limited space to conceal them under the tray.
Fitting this type of runner is quite simple; itâ€™s just a case of positioning the runner in the correct place and screwing it to the carcass, then, with the slide extended, screwing the tray into position.
I spent time locating the drawer correctly to ensure it would look like the normal drawers on either side.
Filing drawer design
The filing drawers had to be dovetailed to match the other drawers and had to resemble deep normal drawers from the outside. The process involves designing and making the dovetailed drawer box to incorporate the Blum tandem runners.
A filing drawer is just a deep drawer with rails fitted inside the drawer carcass for hanging files to sit on. It is very important to measure correctly the type of hanging file you are using to make sure it will run well on the rails, that it has room to hang and room for the plastic tag that often clips onto the top of the file denoting file contents.
This is quite simply a case of measuring accurately and pre-planning enough space for the filing drawer, plus runners, in the carcass. It is also worth mentioning that there are two different sizes of hanging file, A4 and the larger foolscap. In this smaller desk design there was only room for the A4, mounted perpendicularly to the drawer front.
I dovetailed the drawer boxes together, but cut the drawer front joints into a stopped rebate so that the front would fill the aperture. This covered the tolerance left for the runners. The drawer bottoms were also special; because they were solid cedar a small cutout had to be made for the runner at the back. Once complete, no difference could be noticed, other than the shadow line around the drawer front.
The carcass must correspond to a size of runner available, The Blum tandem series starts as short as 250mm equating to a 240mm drawer length and goes right up to 750mm, for a 740mm drawer length in 50mm increments so you should find a suitable size. This information will give you the depth of your drawer carcass, always 10mm shorter than the runner length.
Unlike a dovetailed carcass, a drawer on this type of runner does not fit snugly into the pedestal carcass.
The drawer sides need to be a maximum of 15mm thick and the space between the two sides should be the same as the distance between the inside faces of the two opposing pullout parts of the runners.
The calculations must be done before you start making.
Dovetailing with router and jig
This technique may seem like cheating, but I assure you that it still requires all the skill of marking out and cutting that traditional dovetails do, except you are routing away the waste, rather than chopping it out with a chisel and mallet. It makes the whole process more fun and so satisfying.
This desk design includes seven drawers, six of them of dovetail construction. As you probably know, hand dovetailing is a time-consuming process and adds great expense to a commission because of this. I find generally that removing the waste between the pins takes up the most time, especially if they are lapped.
When I first started work a few years ago, I was shown a technique for using a router to remove the waste, and found this technique very time-saving. This method still requires all the marking out that you would normally do, and all the saw cuts, but by making a jig, which I will explain, removing the waste is quick, easy and accurate, leaving only the final paring to be done by hand.
This simple jig comprises three pieces of 18-15mm board and a piece of solid timber. The jig can be adapted to your needs, but the idea is the same. I personally made mine quite big so that it could cope with big drawer components. Hereâ€™s how to construct it.
1. Create a right angle using two pieces of board the same length, one slightly wider than the other
2. Screw and glue these together along the longest edge, using the narrower piece as the top, and make sure they are square. The third piece of board should be the same length as the other two, but narrower in width by around 25mm
3. Secure this piece to the top board, lining it up with the back edge, the one furthest from the down stand. This difference in width is for a piece of solid wood to sit in and the timber should be accurately planed up to sit exactly in this space, thus completing the right-angle shape
4. Secure this piece of wood to the jig with holes drilled close to the inside edge. This piece of timber becomes your sacrificial edge and is replaceable. It allows you to cut with a router, avoiding breakout. When machining this piece, make several other bits the same so you can replace them easily when needed
1. Screw or clamp the jig to the edge of your bench. Having already marked your pins and cut down all the sides as you would normally do, position the component on the jig, with the end flush with the top of the jig and hold firmly with an F-clamp. This is the surface that the router will run on. Set the depth stop on the router to the thickness of your drawer sides
2. Now position the router on the jig and start to rout the waste areas away, taking cuts at different levels down to final depth, being careful not to run into any pins
Once completed this process should leave you with only minor cleaning up
For lap dovetails, simply fix a fence to the jig parallel or rout to the component to stop the router running through. This will leave you a nice clean line in which to fit your tails.