Category: With the Grain

This is an excerpt from “With the Grain” by Christian Becksvoort. 

With a background in forestry, wood technology, furniture construction and restoration and many decades of joinery, I’ve developed a system of case construction that fully allows solid-wood panels to move throughout the seasons. None of it is entirely original, most is borrowed from antique builders, some is common sense and a minute portion (expansion washers, for example) is my solution to age-old problems. No case I’ve ever restored utilized all of the described techniques, so this is more or less a compilation of the best joinery I’ve had the privilege to restore and learn from.

Once the panels are glued, sanded and cut to size, construction can begin. Edges need to be cut parallel and ends perfectly square. The best sides should be oriented toward the outside and so marked. Then rabbets are cut on the inner back edges to accept the case back. The joints to attach the top to the sides can be a screwed butt joint, single or double rabbet joint, through- or half-blind dovetails, or even a splined miter. If the case is to sit on an applied bracket base, the same joinery can be used for the bottom.

Before gluing the top to the sides, a bit of planning is in order. This is the time to cut matching dados and grooves for any interior dividers, shelves, or web frames to support drawers. If the case side runs all the way to the floor, the bottom is usually dadoed or secured with sliding dovetails 4″-6″ (10-15 cm) from the floor. In either instance, glue or screw blocks (shown below) should be used underneath to strengthen the joint. Once all the interior joinery is cut, the four sides of the case can be glued and assembled.

A web frame (shown at top) consists of four or five narrow pieces dovetailed and mortised and tenoned together to support drawers. Although extra work, they do save both material and considerable weight. The preferred method of building web frames to give maximum support to the drawers, yet allow the cabinet sides to fully expand and contract, is as follows:

The horizontal side-to-side frame members have dovetails on both ends and mortises on the inside edges, right next to the dovetails. The front-to-back drawer runners are tenoned on both ends. The shoulder-to-shoulder dimension of the runners should be slightly less than the distance between the front and back frame members. On the case interior, there should be four short dovetail slots (two per side, to accept the side-to-side frame members), connected by a shallow dado, roughly 1/8″ deep (.32 cm).

To assemble: The front side–to-side piece is glued first. When the dovetails bottom out, the front of the case and the just-installed member should be flush. Next, glue is spread into the front mortises. Then the drawer runners are inserted into the side dados and the front tenon is slid into the front mortise, both left and right runners. Lastly, the back side-to-side frame member is glued into the dovetail slots. The back mortise and tenon are not glued. This allows the joint to telescope in and out, as the case sides expand and contract. The gap between the runners and the back frame member could be as much as 1/8″ to 1/4″ (.32 to .64 cm) if the panels are close to 14 percent MC, and will most likely shrink; smaller if the side panels are closer to 6 percent MC and expansion is anticipated.

A final word about case bottoms: If a solid wood bottom is used, glue blocks should be installed. If, however, a web frame is preferred to save weight, then a dust panel should be incorporated to seal the bottom. Grooves should be cut on the inner portion of the web frame, and a panel fitted during assembly to seal out dust and dirt. Generally speaking, dust panels are not required on other interior web frames.

At each step of construction the case should be checked for squareness. Small errors tend to accumulate if not rectified from the start. Before fitting the back, the case should be carefully checked to be sure it is square. Assuming that both sides are identical in length, and the top and bottom widths are the same, then simple diagonal measurements will point out any errors. Measure from the top left corner of the case to the bottom right, then from the top right to the bottom-left corner. If the two measurements do not match, a clamp between the two longer corners should pull it into position. Re-check the measurements before proceeding to build and install the back of the case.

— Meghan B.

This is an excerpt from “With the Grain: A Craftsman’s Guide to Understanding Wood” by Christian Becksvoort. 

The walnut family also includes butternut and the hickories. Juglans means nut of Jupiter, nigra, or black, refers to the dark wood. Its natural range is from New England through southern Ontario to South Dakota, south to Texas, and east to northern Florida. Walnuts grow best in the deep rich soils of river valleys and bottom lands, where they reach a height of 60′-100′ (18-30 m). The tree generally has an open crown with thick, sturdy branches. Walnut leaves are compound, 1′-2′ (30-60 cm) long, with 13-23 lance-shaped leaflets. Leaves grow alternately on thick, stubby twigs. When cut, the twigs reveal a light brown pith, about the thickness of a pencil lead. Overall, the light green foliage is scant, giving the tree an airy appearance. Early in the fall the leaves turn yellow and drop, leaving a distinctive 3-lobed, notched, leaf scar. The nut matures at about the same time, enclosed in a thick, green, pulpy husk about the size of a billiard ball. The deeply grooved black nut is very thick and hard, but well worth the effort of extracting the meat. The dark brown bark grows in broken, crossed ridges.

Black walnut is as close to a perfect cabinet wood as can be found in North America. The light sapwood, 10-20 rings wide, is often steamed commercially to make it blend with the heartwood, which is a medium chocolate to purplish-brown. The wood is medium hard (with a density of 38 lb/ft³ or .61 g/cc at 12 percent MC), strong and works well with both hand and power tools. Classified as semi-ring-porous the vessels (containing tyloses) are large enough to be seen on any surface. Walnut is very decay-resistant, and was once used for railroad ties. Many early barns, houses and outbuildings in the Appalachians and the Midwest were constructed with walnut frames. Its color, beauty and workability make it a prime cabinet wood. Gunsmiths use it for stocks because it moves very little once dried. Top-quality veneer logs will sell for thousands of dollars and will panel miles of executive offices.

— MB

This is an excerpt from “With the Grain: A Craftsman’s Guide to Understanding Wood” by Christian Becksvoort.

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).

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.

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.

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.

— MB

An excerpt from “With the Grain: A Craftsman’s Guide to Understanding Wood” by Christian Becksvoort.

Eastern white pine is also referred to as Northern, soft, balsam or Weymouth pine. The name Pinus refers to the pine family, while strobus means cone. The tree’s natural range is from Newfoundland to Manitoba, south to Wisconsin and Iowa, and east to the Appalachians down to Georgia. Ordinarily it reaches heights of 80′-100′ (24-30 m). Old king’s broad arrow pines, used for masts in the royal navy, sometimes grew to more than 200′ (60 m). White pines can reach 400 years of age.

Pines, like most conifers, grow a straight central trunk. The branches of white pine grow almost horizontally, usually in groups of five. The pine shoot borer, an increasing pest in pine-growing areas, kills the leader, forces one of the branches to take over as leader and results in deformed or multiple trunks. Pine needles are 2″-5″ (5-12.5 cm) long, grow in bundles of five, and are surrounded by a papery sheath at the base which drops off after the first season. White pine cones are 4″-8″ (10-20 cm) long, fairly thin, quite flexible and take two years to mature. The bark forms gray scaly ridges.

Sapwood of white pine is pale yellow-white. Heartwood is cream to light reddish-brown when freshly sawn, turning to a warm reddish-brown on exposure to air and light. Old, clear heartwood is often referred to as pumpkin pine. The wood contains a fair amount of pitch. It is generally straight, even grained and light, with a density of 25 lb/ft3 (.39 g/cc) at 12 percent MC. It is a real workhorse in most shops, used for jigs, braces and mock-ups. As a pattern wood it has no equal. Quartersawn white pine is the most well behaved of all the native woods. Pine’s ease of sanding, chiseling and planing makes it an ideal secondary wood. When used as such, it fills the entire interior of a chest or cabinet with a clean, woody odor. It is also used as a primary wood. Most of New England’s painted antiques are constructed of white pine. Shellac over the knots prevents the pitch from bleeding through. Perhaps it appears at its best when left raw, or oiled to age naturally.

— MB