Fine drawer making, part 1
Sylvia tall chest, 1996, Neil Erasmus, showing decorative through dovetails and bookmatched flame jarrah veneers to fronts. Photo: Robert Garvey
Words: Neil Erasmus
Fine drawer making is often considered to be a true test of the ability to work to exacting tolerances and like chairmaking, a meaure of a maker’s skill. Most furniture makers are regularly called on to design and construct pieces containing one or more drawers that serve a specific purpose, and occasionally they may be asked to make something very special which simply would not be right with anything less than finely crafted drawers.
This is the first of two articles that deal with the layout, making and fitting of a fine drawer. These methods and recommendations suit my modus operandi and therefore represent only one way of skinning this particular cat.
By hand or by jig
Traditional hand skills are involved, although you could combine methods to use machine-cut joints or a router and dovetailing jig. One important point to bear in mind if using a jig, is to design the layout of the drawer to suit the finger guide on the jig. The drawer height has to be a multiple of twice the width of one of fingers, so if a finger measures 11mm then the drawer has to be 22, 44, 66mm and so on. This ensures that the drawer front ends up with a neat half pin on both the top and bottom.
Allow for wood movement
Remember the drawer opening needs to be slightly larger to allow for the wood movement caused by changes in humidity. I normally allow 0.75mm per 100mm of drawer height in the dry months and 0.25 in the wet or humid ones.
Seasonal changes in relative humidity also have to be carefully considered when designing the carcase or frame that houses the drawer. No one can prevent wood from expanding when it sucks in moisture from the air, and then shrinking again when dry air sucks it back out again. This expansion and contraction occurs across the grain and should be allowed for in the design and making of solid timber furniture. To ignore this basic principle by gluing across the grain will ensure the unavoidable self destruction of your handiwork due to the huge stresses which occur when wood wants to move but can’t.
The drawer described here is a typical fine drawer, made of solid timber, dovetailed by hand at the front and pin mortised and tenoned at the back. A solid drawer base slides in grooves in slips attached to the sides and a groove in the front. A typical fine drawer is made from fairly slender sections of timber, without compromising strength. It is nice to cut very fine half-blind dovetails to the front, which boast very narrow pins and low angles. I like to design my pins to have a base of no more than I mm, just enough to get a dovetail saw through when cutting the tails.
The drawer slips serve to support the base without weakening the sides, which would otherwise be compromised by their fine nature. Because these slips are flush with the underside of the drawer they offer a broad gliding surface with increased support area which wears very well. You could make a drawer without these slips but the sides would then need to be much thicker so as not to weaken the area where the base fits into the groove. Another advantage of slips is that they are removable for repair or replacement without taking the drawer apart.
Before we get started there are some important considerations to bear in mind regarding the choice of timber for construction. I always use quartersawn wood for the backs, sides and slips, and also on the fronts if they are higher than about 150mm.
Quartersawn timber moves less across its face than backsawn timber does and importantly doesn’t have a tendency to cup which can cause jamming. It also has a plainer, linear grain pattern which is nice on the inside of a drawer.
My choice of timber type is crucial, lightly coloured medium density timber whose grain will compress relatively easily to facilitate easy assembly. I occasionally veneer decorative veneers over quartersawn fronts for visual impact or if I’m making a multiple drawer chest where bookmatched veneers have a striking effect (as shown above).
I get my drawer sides and back material specially quartersawn and dried to16mm thick. Removing equal amounts of material from both faces will result in a very stable, dressed piece of timber, which is unlikely to suffer from cupping, bowing or twisting, thus ensuring a smooth running drawer for decades to come. If you are forced to use thicker material roughly dress it down to 15 or 16mm and allowing it to settle ‘in stick’ for 3 or 4 weeks in a dry ventilated area before remachining.
If, for example, you split 1-1/ 2" material in half, lay these planks down for a week (new face up) so that the moisture in the wood can equalize between the new face and the old. It’s then advisable to leave these for at least six weeks in stick to stabilise. It doesn’t take long to figure out that you need to think ahead when dealing with well designed, quality furniture.
I always use a solid, aromatic timber such as cedar of Lebanon, sandalwood or camphor laurel in my drawer bases. These are sometimes covered in leather, through which the fragrance will travel. A base made in the same timber as the rest of the drawer is also acceptable.
Machining to size
Once I have selected all my timber (plus an extra piece or two in case something goes wrong). I dimension them to the sections I require. The front and sides are planed and thicknessed to the precise height of the opening less the calculated slack for movement.
The back, and divider if used, have a height of 16mm less than the front and sides, and provide a passage for air to escape when opening and closing the drawer and also prevent jamming. I try to thickness drawer fronts to maximum thickness from 1" stock, and with careful machining generally get around 22mm.
The sides, backs and slips are all machined to the same thickness, and depending on the size of the drawer, vary from 7–l2mm. I use the smaller size in my document boxes. The height of the slips is around 21–25mm, depending on their thickness and the height of the drawer base, the calculation being: height of drawer base (not thickness) plus thickness of slip. This ensures you end up with a square section of material above the drawer base from which a neat quarter round or bevel profile can be machined.
The base of the drawer runs from side to side with movement taken care of in the groove in the front. I resaw l–2" stock on the bandsaw into 8mm thick pieces which I machine down to 6.5mm and then edge plane and join. This then gets sanded, cut to size and rebated to fit the grooves in the slips and front. If I am making a very wide drawer, I fit a muntin in the centre and use two drawer bases, which I cut from one panel so that the grain remains uninterrupted.
Once all these sections have been machined to the required sizes I cut them to length using a sharp tungsten crosscut circular saw. You don’t want any chipping out on edges and corners, so if necessary, use a sacrificial block of timber behind the piece to prevent this from happening. First cut the drawer front to a tightish friction fit in the opening then, adding 1mm to this length, cut the drawer back. This allows 0.5mm for flush sanding after assembly.
Now cut the sides to length, allowing 5 or 6mm clearance at the back to allow for wood movement in the carcase, and 4 or 5mm at the front for the lapping on the dovetails. In the case of a very long drawer I add a divider which is identical to the back, somewhere around two-thirds of the way back. Such a long drawer will always glide a lot smoother than a short one, which sometimes has the tendency to jam on the diagonal. The slips remain uncut until the drawer has been assembled.
In part 2 we will look at design and layout, and take an in-depth approach to the handwork involved in cutting the dovetails and fitting the drawer.
First published in Australian Wood Review, issue 22, March 1999
Neil Erasmus is a furniture designer/maker in Perth, WA and also teaches woodwork. See www.erasmusdesigns.com