A Chippendale apple secretary desk and bookcase featuring triple-cusp scrolled returns. Colchester School, possibly Hebron or Lebanon, Conn., 1785-1805.
Dimensions: height: 76-5/8″, width of lower case: 42-1/8″, depth of lower case: 19-3/4″, width of upper case: 40″, depth of upper case: 10″, width of cornice: 42-7/8″, depth of cornice: 11-1/4″.
This Chippendale apple secretary desk and bookcase features subtle decoration executed with fine quality and strong lines. The tall and stable straight bracket feet are adorned with triple scrolls, featuring a large lobe, a small pointed return and a second smaller lobe. The graduated asymmetrical returns are a simple but effective design showing awareness of more sophisticated New London County furniture made in the urban centers of Norwich and New London. However, this secretary was made in the Colchester area, likely in the successful farming community of either Hebron or Lebanon. Instead of complex serpentine forms or carved decoration, the cabinetmaker relied on the inherent beauty of native apple. He relied on his skill at creating quality lines and form to exploit the interesting patterns within the material. The irregular nature of the grain in apple makes it a challenge to use in furniture. The reward is the beautiful figuring and warm reddish-yellow tone. The large at panels used in the bookcase display apple at its nest. Two bookmatched sections of apple are used for the two door panels, each with the pattern of striped figuring is set at complementary angles. To accentuate the natural beauty of the panels, the cabinetmaker has created a bold projecting cornice moulding. The layering of narrow and wide sections meets in the front corners with flaring lines pointing back toward the panels. The original owner of this secretary may have lived in a rural farming community, but he was successful enough to own books. Displayed in an 18th-century home, the secretary was a statement that the owner could read and write. This was an important status symbol at the time and was a sign of education, knowledge and success.
The probability is that the haunch came into being as a matter of necessity. You know how, when making a door with grooved-in panel, the plough has to run right through so that a haunch to fill in the groove at the end simply has to be cut. It was soon perceived, however, that it does strengthen the joint because it opposes any twisting tendency at the otherwise unsupported end of the rail. This is explained in Fig. 1, which shows at A how there is nothing to prevent the edge from twisting should the wood be liable to do so, whilst at B the haunch offers direct resistance.
Some applications of the haunch are given in Fig. 2. At A is the grooved frame-work in which the haunch is essential to fill in the end of the groove. B is a plain, square-edged framework, whilst C is the same, but has what is known as the secret haunch. In many ways this is the best type of haunch. It is entirely concealed, it offers full resistance to twisting, and it is stronger since the short grain to the outside of the mortise is not cut away unduly. It can be applied to all tenon joints except the grooved type at A in which the haunch must fill in the groove end. A rebated framework joint is given at D, whilst E gives the application for a moulded and rebated framework.
FIG. 2. APPLICATIONS OF THE HAUNCH IN MORTISE AND TENON JOINTS. At A the haunch fills in the end of the groove. B is a square-edged framework. C is the secret or concealed haunch. D gives a rebated framework, and E is moulded and rebated.
FIG. 3. HOW HAUNCH IS MARKED AT THE END.
The haunch should always be of the same thickness as the tenon, even when the groove (if any) is of different size. Take A, Fig. 2. It might easily happen that the groove was narrower than the tenon, and in this case it would merely be a case of enlarging the groove at the end to line up with the mortise.
When marking out the joint, always carry the mortise gauge along to the end of the wood as in Fig. 3, and continue down the end grain. The depth at the end can also be gauged in. The marks will not matter because they are removed when the waste allowance (shown shaded) is cut off. The haunch length should be squared across the outer edge of the tenoned part during the original marking out. A chisel should be used as this gives exact marking. In the case of the secret haunch at C, Fig. 2, allow it to stand in a trifle (see x) so that it is not revealed in subsequent trimming.
FIG. 4. PROPORTIONS A AND B ARE BAD. C IS CORRECT.
The proportion of the joint has to be considered (see Fig. 4). At A the tenon is so wide that the short grain beneath the haunch has little strength. If the tenoned piece were wrenched round it would probably split open the mortise. B goes to the other extreme, the haunched portion being strengthened at the expense of the tenon. At C a good proportion is shown; each part compromising to give the required strength.
When your nails are driven home, you’ll have a small forest of nail tips awaiting you on the inside of your bottom assembly. You’ll be turning these over and back into the bottom boards using the power of clinching.
Clinching (sometimes spelled “clenching”) is when you drive a nail that passes through both thicknesses of wood you are fastening. The tip of this nail sticks out about 1/4″ and is bent over and driven into the wood.
Clinching adds remarkable strength to a joint. A 1948 study by the U.S. Forest Products Laboratory concluded that clinching can increase the holding power of a nail between 45 percent and 464 percent – depending on a variety of factors, including the species of wood and its moisture content.
Also interesting: The study concluded that bending the tip across the grain increased the holding power by 20 percent compared to a nail clinched along the grain.
But how do you best clinch a nail? There are several methods.
Four Ways and a Trick
Here’s how automated clinching machines do it: They fire a nail in at an angle, and there’s a steel plate waiting for the nail’s tip when it emerges. When the nail hits the steel it bends over into the wood – essentially it ricochets like a bullet or pool ball.
I’ve never tried this with a pneumatic nail gun, but it sounds like fun on a Friday afternoon.
For the hand clinchers, there are at least two common techniques. The first one is to first drive the nail through the work. Rest a steel plate, anvil or a second heavy hammerhead on the nail’s head. Then tap the tip of the nail with your hammer. It will curl over. Then you can drive the drooping tip back into the wood.
The second technique is similar to the machine process. You drive the nail through the work and against a waiting “bucking iron,” which curls the tip and forces it back into the wood.
I have a steel plate behind the head of this nail as I clinch it. Here is the nail tip right before the first strike.
The head begins to bend after the first strike.
After two strikes the nail’s tip is at a 90° angle to where it was originally.
Three strikes and you’re down. (Note: Thomas does this in the book with one less strike. Precocious boy.)
One final strike drives the tip back into the wood. This is as dead as a doornail.
If you don’t have clinching confidence, try bending the tip a bit with needlenose pliers – then drive the nail home.
There’s one more technique I’ll sometimes use when I’m being really, ahem, retentive. I’ll drive the nail through. Then I’ll use needlenose pliers to bend the tip to the angle I want. Then I’ll drive it into the work. This results in a tidy appearance. I admit it’s a bit much.
When I have a lot of clinching to do, I’ve found that a cast iron table saw wing can be your best friend when clinching at work – doors, lids and the like. Lay the cast wing on your bench and you have a nice big area to support your work as you merrily clinch away. And no, the clinching does not really mar, crack or otherwise defile the cast iron wing.
The process of glueing up is one of the most important in woodwork, and requires the attention of all craftsmen who strive to endow their work with the vital qualities of endurance and stability. Often the best methods are the easiest to use; they save labour, and result in a cleaner finish to a job.
PREPARATION OF GLUE Quality in glue depends upon its purity; therefore it is advisable to pay a good price. The best Scotch glue is pale in colour, and is usually in thin cakes. It is is prepared by soaking in water overnight so that it absorbs the correct amount of moisture to make it of the right consistency when hot.
It is, of course, heated in the glue pot with proper water container, and is ready for use when a skin forms on the top of the liquid. If a little powdered alum is stirred in during the heating the glue will be rendered waterproof, or, at any rate, resistant to damp. Never heat glue over a naked flame. It only burns it and causes it to deteriorate.
APPLICATION The butt or rubbed joint is usually one of the first to be prepared and glued up in most jobs. For this joint the glue MUST be thin, that is, will run from the brush in an unbroken stream, but not thin enough to splash, or break up, as it falls. Certainly it must be hot, and be kept hot while being used, preferably in a warm atmosphere.
We all know how this joint is made; it has been described so many times, but many workers, both amateur and professional, find that it sometimes comes apart after a short time, the parting generally commencing and “running in” from the ends of tops, etc.
A butt joint that is completely and permanently successful is obtained by the writer in the following simple manner: The edges of the boards to be joined are first shot straight and true, as usual. Next, they are planed a trifle hollow, usually about 1∕32 of an inch, each edge, or sufficient to make the ends of the boards pinch together tightly when the joint is cramped up. These hollow edges are lightly toothed and are warmed before being glued and rubbed together.
FIG. 1. GLUEING UP RUBBED JOINTS
When being assembled they are placed across two trestles or similar supports.They are quickly cramped together, the number of cramps varying according to the length of the joint.
The advantage of this method is that the greatest pinch or holding power occurs at the ends of the joints, where fracture generally begins.
FIG. 2. APPLYING GLUE TO DOVETAILS
GLUEING DOVETAILS Drawers and other dovetailed joints can be cleanly assembled by brushing the glue on the inside corner of the tails or drawer side, at the same time forcing glue into the small openings where the pins fit (Fig. 2). Glue is transferred to the base of the pins by quickly rubbing the glued end grain of the drawer side across the width, at the back of the drawer front, care being taken to avoid smearing glue below the gauge line. (Fig. 3).
The drawer side is lightly tapped into position with a light hammer, and a joint is obtained with the absolute minimum of surplus glue adhering to the inside corners of the drawer.
FIG. 3. HOW PINS CAN BE GLUED WITHOUT MAKING MUCH MESS
VARIOUS JOINTS With mortise and tenon joints the best procedure is to apply a little glue to all four sides inside the mortise, at the same time allowing a little to adhere to the edge to join up to the shoulders of the tenon, thus effecting a clean joint.
To ensure a permanent dowelled joint, it is best to countersink the holes, and tooth or roughen the dowels before they are cut into short lengths from the whole stick. After cutting to length, a saw cut is made along the length of each to allow surplus glue to escape. After inserting a little glue into the holes on one side of the joint, using for the purpose a foot of dowel rod sharpened at the end, the dowel pegs are driven in.
Mitres and similar small butted faces should be warmed before glueing, and are then rubbed together. If pins are to be used these can be driven in after the glue has set. Glue-blocks should always be rubbed on, and if previously warmed so much the better.
With all joints the aim should be to use sufficient glue to make the joint, with only a very small surplus to be afterwards cleaned off: there is no need to smother it with the glue. Remember that only the glue in the joint is used, the surplus is wasted.
As a final word, always wipe off surplus glue before it sets. Keep a clean swab and can of clean hot water for the purpose. Do not use the water in the glue pot. It is usually dirty and will probably discolour the wood.
A commonly encountered misconception is that wood breathes. As we know, heartwood is composed entirely of dead cells, while sapwood has some living cells, which die after the wood is cut. Nonetheless, wood is an organic substance that by its nature responds to climatic changes. Moisture is absorbed or given off as the seasons dictate.
When the relative humidity rises, the wood fibers absorb moisture that penetrates from the outside and causes the wood to swell. As the humidity decreases, excess moisture is given off by the fibers to be reabsorbed by the surrounding air. Wood is constantly trying to maintain a balance between its moisture content and that of the surrounding environment. This balance is called the equilibrium moisture content (EMC). Simply expressed, it is the amount of moisture present in wood at a given temperature and relative humidity over a period of time (Fig. 4-9).
Fig. 4-9
A closer look at Figure 4-9 shows that humidity is only one factor in determining EMC. Temperature also plays a role. For instance, at a given temperature as humidity rises, the EMC of the wood increases dramatically. This is to be expected. On the other hand, as relative humidity remains constant and temperature rises, the EMC of the wood goes down. Water in the cell walls is in liquid form. As the temperature goes up, the water becomes gaseous and escapes into the warmer air.
Relative Humidity
Relative humidity is expressed as a percentage of the amount of moisture that the air is capable of holding at a given temperature. Warm air can hold more water vapor than cold air. For instance, at 86°F (30°C) and 100 percent relative humidity can hold five times as much water vapor as air at 43°F (6°C) and 100 percent relative humidity. Hence, it is a good idea for a well-equipped wood shop to have a thermometer and hygrometer.
Fig. 4-10. (A) Average relative humidity in July, at noon, local time. (B) Average annual precipitation, in inches. (C) Average recommended moisture content of wood for interior work.
Location, as well as time of year, determines the average humidity. Figure 4-10 shows the average humidity in the United states for July, as well as the average rainfall. The third map takes both of these into account, as well as the corresponding equilibrium moisture content from Figure 4-9, to arrive at a general composite map of average moisture content of wood intended for interior use in various parts of the country. This map should only serve as a rough guide, because local conditions can vary.
Air Drying
Numerous considerations influence the air drying of lumber, among them:Climatic conditions. Generally speaking, very little drying of lumber is possible during the winter, particularly in those areas where the temperature remains below freezing. Moisture close to the surface can evaporate by the process of sublimation, whereby the water goes from a solid state (ice) directly to a gaseous state (vapor) without becoming a liquid. In areas where winter temperatures are relatively mild, some drying will occur, as long as rainfall and humidity are not excessive. Drying rates are variable and often very localized. The location of the drying pile and even its orientation to the sun and prevailing wind all influence the rate of evaporation.
Fig. 4-11
Species. The wood species makes quite a difference when it comes to length of drying time. Specific gravity is a fairly good general indicator of drying rate. The lower the specific gravity, the faster the drying time. The softwoods and lighter species of hardwoods dry faster under favorable conditions. The percentage of sapwood and heartwood also plays a part. For example, sugar maple dries faster than Northern red oak with roughly the same specific gravity, but sugar maple has more sapwood. Figure 4-11 lists the approximate air- drying times of some native woods.
Thickness. The old rule of thumb “one year of drying for each inch of thickness” has no basis in fact. First, it does not take species into account. Second, drying time is a function of the square of the thickness. This means that 8/4, or 2″ (5 cm) stock takes four times as long as 4/4, or 1″ (2.5 cm) stock. In fact, for some species the drying time is even longer than the square of the thickness. This is one reason (along with the differential between radial and tangential shrinkage, described in Chapter 5) why it is next to impossible to dry entire logs without serious cracking or checking.
Grain orientation. Quartersawn wood is slower to dry than plain-sawn wood. The ray cells aid in drying, and although they appear more prominent on quartersawn wood, not nearly as many are exposed on the face of the board.
Pile construction and foundation. The actual method of stacking the wood has a lot to do with the drying rate. Adequate space left around each board aids in drying. Many smaller piles dry faster than one large pile. The pile foundation should be well off the ground to allow for free air movement underneath. Weeds and debris should not obstruct the air flow. Finally, the ground should be well drained, with no standing water.