A Box of Four Woods.
My thank-you celebration of wood.
Recently, I found myself with a lot of people to thank for doing me a big favor in my professional life. I wanted to make them a keepsake, something personal for them, and something that was personal from me. I decided to make a small wooden box, something very simple, made by my hands from materials that came from my life. The result is what I call A Box of Four Woods, and here is its story.
Not unsurprisingly, A Box of Four Woods is made of four different species of wood. Each variety of wood has its own special character and plays a unique role in the box’s construction. Additionally, each wood represents something very special and personal to me.
Six years ago, Sue and I moved to a 50-acre former dairy ranch in Petaluma, about an hour north of San Francisco. We call it Monkey Ranch, and three of the woods used in the box come from that ranch. Two of the woods are recycled from their previous lives as part of structures on the ranch.
Redwood: the sides.
The four sides of the box are made from redwood, a locally native tree with remarkable characteristics. This particular redwood is quite special and is really the inspiration for the box. It is old-growth redwood originally milled from ancient trees. Because of necessary protections, such wood is no longer commercially available. The only way to get it is to recycle it from some old building, which is the case here. It was salvaged from the rear wall of the Tractor Barn, one of the seven old barns on the Ranch. Old-growth redwood has become quite scarce, and can only be acquired by recycling old boards, which is why — if you’re lucky — you might find an old nail hole or other defect in the wood. The grain is tight, straight, and uniform, reflecting its age and remarkable qualities. There’s no way to tell how old this wood is but I like to imagine it came from a tree that was 800 years old. The boards then spent 80 years on the back wall of my tractor barn, and now I hope they will serve on this keepsake box for at least another 80 years!
The coast redwood, or Sequoia sempervirens, can be found only on the steep slopes of the coastal mountains of northern California and a corner of southern Oregon. These mountains get a lot of rainfall in the winter, and in the summertime are swathed in the dense, fast-moving advection fog that rises off the surface of the Pacific Ocean.
The redwood’s soft shaggy bark insulates the trees from forest fires and confounds burrowing insects. Redwoods grow in family circles, called groves, sharing the roots of their siblings and their ancestors. These dense groves let the trees work in harmony to protect themselves against storms, supporting each other against the wind, allowing them to grow exceptionally tall, rising hundreds of feet, with a few giants exceeding 350 feet, the tallest trees in the world.
Up until the 1970s when forests were decimated and conservationists halted the logging, redwood was a common construction wood in the Western United States. The trees it came from were the originals, from forests thousands of years old. Many of the felled giants were 700, 800, or more years old.
The wood cut from such old-growth trees was — and is — miraculous. Carpenters loved it! It was light yet strong, easy to work yet dimensionally stable. The dark maroon wood was astonishingly weatherproof, termites hated it, and the only way to get it to rot was to immerse it in standing water for a few years. When you get a sliver of redwood in your skin — even a tiny one — it stings annoyingly because of the insect-repelling compounds in the fibers.
In the late 19th century, railroads and the steam engine allowed the wholesale harvest of the abundant redwood forests of Mendocino and Sonoma counties. Each big tree could yield hundreds of thousands of board feet of construction lumber. Much of San Francisco was built of this redwood, and after the devastating 1906 earthquake and fire, it was built once again with more redwood. The old farmhouse Sue and I live in was built of this incredible wood, and it has withstood more than 130 years of wind and weather — including the famous quake — and it’s as sturdy today as it was in 1879.
Out here in the west you can still buy redwood lumber at the local big box store, but it is nothing — nothing! — like the old-growth wood that came from the ancient trees. As they say, wood of this quality and character doesn’t grow on trees.
Not only have most of the old redwoods been cut down, but the complex ecosystem that allowed them to evolve has been grievously wounded. Those old redwood trees way up in the mountains were fertilized by fish!
Each of those steep-sided, serpentine valleys that are home to the redwood tree was cut by a seasonal mountain stream. Starting at the top as a tiny rivulet during the winter rainy season, they drop fast through the undergrowth of ferns, gaining speed and mass and carrying deadfall and silt out into the broad Pacific. Annually, in the ocean, salmon and steelhead trout sense the presence of the onrushing mountain mud and know it is time to return to their spawning grounds. They swim up the rivers, then up the streams, then up the creeks, then up the tiny rivulets to the very highest spots in the mountains. There they finally stop, spawn, and then die. Their rotting carcasses collectively deposit millions of tons of rich nutrients into the soil. Scientists have traced the DNA of salmon in the DNA of ancient redwoods. I’m sure it’s a coincidence that the flesh of the Salmon is pink, and the fibers of the great trees it nourishes are red, but it is remarkable.
Construction, dams, flood control projects, and pollution have reduced the fish population enormously. Agricultural chemicals have poisoned the waterways, and not enough fish are rising to the headwaters to continue what scientists call the anadromous cycle. Mother Nature doesn’t wait, and she always maintains a balance. The assumption that the ancient redwood forests can and will come back if given enough time is more than likely not the case. That wood is gone forever.
Douglas fir: the bottom.
The bottom of the box is made from Douglas fir, the ubiquitous construction lumber used throughout the western US. Like the redwood, this wood is recycled and is either old-growth or older growth. Also like redwood, contemporary Doug fir is a pale shadow of its ancient brethren.
This particular wood was part of the huge hay barn at Monkey Ranch that we converted into my workshop. The original hay barn was the newest on the property, built in the early 70s, but these boards are still at least 40 years old. A hay barn is basically a large cow feeder. Hay bales are stored in the central section and the cows stand in “alleys” alongside to eat. The hay barn lacked walls, as all it had to do was keep the rain off the hay bales. In place of walls, there were low inner barriers comprised of 24-foot long 2-by-12s of Douglas fir. The ranch hands would fork hay from the bales over the low inner barrier into a three-foot wide gap bounded on the outside — the cow side — by an open zig-zag structure of 2x4s. This zig-zag, called a manger, kept the cows heads apart and down while they ate the hay.
When we converted the barn, we removed both the low inner barriers and the mangers, and the wood salvaged from them has been used for many projects around the Ranch, including the bottom of A Box of Four Woods.
The Doug fir commonly available to builders in the 1970s was high quality lumber, with even, straight, close grain. It wasn’t as robust as redwood, but was substantially superior to what passes for Doug fir today. The fir you buy now is second- and third-growth. The ecology of forests is complex and not well understood, but these new trees are not much like the old ones. The seasonal growth rings are far apart, the wood is weak and warps severely. It has little resistance to rot or termites, which is why it is often pressure-treated with poisonous copper sulfates.
Some of the pieces of Doug fir I used on these boxes have the interesting characteristic of being light on one side and dark on the other. Where that was the case, for aesthetic reasons, I put the darker side out and the lighter side in. The wood was turned dark by decades of exposure to cow poop! The ammonia in cow exhaust turns wood dark. The characteristic dark oak of Craftsman-style furniture made in the 1920s and 30s isn’t stained but is actually pale, white oak that has been “fumed.” The furniture makers would turn the oak dark by sealing it in a box with an open pan of ammonia for a day or two.
The majority of the old barrier boards were milled smooth then cut into two-foot lengths to become the shelves in my library. It seemed a shame to cut up those 24-foot long beauties, but it’s good this way, as the shelves are in the open and clearly visible where they can be appreciated. Otherwise, they’d be sealed up inside a wall on some construction site.
Carpenters and cabinet makers separate wood into two categories, hard and soft, but these are misleading terms. A “hardwood” comes from a deciduous tree and a “softwood” comes from an evergreen. By this definition, two of woods I used on this box are hard and two are soft. Douglas fir is a pitchy evergreen tree, so it is nominally a softwood, but once it has dried for a few seasons, it is harder than many hardwoods, and quite dense and strong. The other soft wood, redwood, is actually quite soft. You can score it easily with your fingernail. But the old-growth redwood is also quite dense, so it is forgiving of these little marks and scratches.
California black walnut: the top.
The top of the box is made from California black walnut, a lovely dark hardwood with prominent grain. Black walnut is deciduous, therefore a hard wood, but it is relatively soft. It’s easy to saw, plane, and chisel.
This walnut comes from a large tree that was growing in the front yard of the farmhouse on Monkey Ranch when we purchased it. Even then, the tree was clearly crippled and senescent. There was evidence of rot, birds lived inside it, and ivy grew out of its truncated top, but I strongly suspected that hidden inside was a bonanza of gorgeous wood. In the spring of 2014 we cut it down and during the summer milled it into boards. The wide planks lived up to our expectations. The wood is richly beautiful and figured. It is primarily a deep, chocolatey brown, but some parts of it are multicolored swirls of rippling grain with traces of orange, silver, yellow, and black. Some woodworkers would let knots and other inclusions fall to the shop floor, but I’ve included them where I found them. I think they bring interest and beauty to the wood.
This particular walnut tree was a puzzle to me from the day we first laid eyes on the old Zimmerman diary, long before we purchased it and turned it into Monkey Ranch. There was something odd about the old tree. It took me years to piece this story together by asking around and listening to the old timers in the neighborhood. Over homemade wine they would tell me of the clever strategies of their brave ancestors who crossed the oceans and settled here.
The Miwok and other indigenous tribes in California harvested black walnuts, then ground them into flour to bake. Today, only the gray squirrels eat them. But being a native tree, it’s quite well adapted to our climate and grows healthy and strong. The familiar walnut we enjoy eating in the fall is an English walnut, and a staggering quantity of the nation’s walnuts come from endless orchards in California’s Central Valley, a few hour’s drive southeast of here. But every one of those English walnut trees are grafted onto California black walnut root stock. The sweet taste may come from England, but the health and endurance are from right here.
When we bought Monkey Ranch, the huge black walnut in the front yard was a striking specimen simply because it looked so ridiculous. The trunk was imposing, broad, enormous, the biggest walnut I’ve ever seen! Most black walnuts trunks are a foot or so in diameter. This one measured almost five feet across down near the ground, and it was at least four feet across as it rose to its majestic height of…15 feet, whereupon it simply stopped! The tree just ended, not flat from having been sawn, but rough and bumpy as though severed by some natural cataclysm. I would expect a tree of this girth to rise 80 feet into the air spreading its branches wide. Instead of branches, this stump-like tree sported hundreds of suckers: smooth-skinned young branches reaching for life. Growth such as that indicates the tree is desperately trying to compensate for damage or loss. From old photographs, we could see that these suckers had been cut completely off more than once but had just regrown. Everything about this odd tree was an intriguing puzzle.
There were several other, smaller and younger, black walnuts growing in the yard around the house, and one of them provided the first useful clue. This trunk was only about 8 inches across, and it was about 25 feet tall. One day I noticed that there were two different kinds of leaves growing out of the tree, black walnut and English walnut. Clearly, it was a graft, but the surprise was that the change in foliage came at a height well over my head, not down above the root crown where I would expect it. There must be some reason why they made the graft so high off the ground.
The old Italian immigrant farmers who settled this part of Marin County a hundred years ago were canny naturalists, and they knew that English walnuts were good eating, but they also understood that the wood from the black walnut was superb for furniture making, gunstocks, and other decorative uses. Now, orchardists are all about quantity, so their grafts are made right above the root crown, a few inches above the soil. But the old Italians made their grafts ten or more feet above ground. They knew that someday, they — or their descendants — could harvest the trunk of the tree for building materials.
Our farmhouse was originally built in 1879. For California, that’s very old. For our big walnut tree to achieve a girth of over four feet, it had to have lived for at least a hundred years. In my imagination I can see an old Italian rancher, standing in front of his newly-built house, deciding to graft an English walnut onto the strong young black walnut tree that grew naturally in the yard. He made the graft high off the ground, so that one day he, or his children, or some aging computer programmer could have the benefit of the wood. Then, a hundred years later, with the old Italian rancher long in the ground, a storm, a high wind, or a wayward tractor bent that tree hard enough to snap it off at the graft, now 15 feet off the ground. The ivy and the birds occupied it temporarily until I came along and brought the tree to its next life.
Ash: the lining.
The inside lining of A Box of Four Woods is made from ash, a hard, strong, sinewy wood well known for being used to make baseball bats. This is the only one of the four woods in your box that came from the store. You won’t find any ash at your local big box building supplier. It came from a hardwood dealer in the little town of Windsor, a few miles north of where I live. Store bought wood is generally kiln dried, and ash doesn’t grow native in California, so this wood likely came from somewhere several hundred miles north of here, and quite possibly from New England, where ash grows everywhere.
Ash trees in North America are currently under assault by the emerald ash borer, a worm imported from Asia. It was probably brought here accidentally on solid wood palettes or crates. The voracious worm has already killed hundreds of millions of ash trees and appears to be unstoppable.
Ash is a pale, open-pored wood easy to mistake for white oak. It’s stable and workable, but it has one unique quality that makes it especially well suited to use for the inner lining of a small box. Ash’s strong linear grain allows it to keep its strength even when re-sawn into very thin slices, exactly like the re-sawn slices used to line the inside of the box.
In thin slices, ash is very resilient wood and bends quite easily. If you steam it, it can bend to extremes and will hold its shape once it’s dry. I use ash a lot in my shop for any project that calls for a hard wood.
The four redwood walls of the box are joined using a finger joint, also called a box joint, as it was used frequently to make wooden cases back in the day when food and other common commodities were packaged and shipped in wooden crates.
The finger joint is strong because it has lots of surface area on both pieces in close contact. The bulk of this surface area is side grain rather than end grain. While end grain looks nice, it has virtually no glue-holding power. Two end grain pieces glued together will just fall apart, but a good side grain joint like this one is stronger than either piece of wood.
The other reason why the finger joint was used a lot back in the day was because it could be cut by machine. A classic dovetail joint must be cut by hand and takes a lot of skill and time. A dovetail would deliver a level of strength that would be overkill in a box of this size.
I cut the finger joints on my table saw with a blade made especially for this job. Most power saw blades have cutting surfaces with angled tips, giving the bottom of a typical saw kerf (the part cut away) an inverted “M” profile. The finger joint blade has cutting tips that are perfectly flat across so the bottom of the resultant kerf is also perfectly flat. It’s not quite as efficient for building a house, but perfect for making boxes.
Of course, the blade is just part of it. The cuts themselves have to be precisely spaced and of a uniform depth. I accomplished this by building a jig. The finger joint jig rides on top of my table saw holding the side walls of the box. I slide them across the blade to make the first notch. Then I slide that notch on top of a precisely sized and located wooden pin, and cut the next notch. Each notch gets placed over the pin in turn as the new notch is cut, thus guaranteeing that the notches are uniformly spaced. Of course, the notches have to mesh, so two of the sides have to be offset by exactly the width of a notch for the first cut. It takes some practice, but once you get going it’s easy.
Once the four walls are glued together, the walnut top and the Doug fir bottom are attached. Both the top and bottom are joined in the same manner. I sawed a shallow, one-sided groove — called a rabbet — along all four edges of each piece. The box fits perfectly into the rabbets and a little glue keeps it there.
At this point, I have a nice box but with no way to open it. It’s glued shut on all six sides. It has to be cut open to be used. That might seem more complicated than building the top and bottom separately, but not only is it easier, it also means that the grain matches closely from top to bottom.
I used my big table saw to cut off the box top by running all four sides of the box across the blade. However, this operation would be very dangerous if done incorrectly. When you get around to the fourth side, the top of the box will come completely free at the end of the cut. A loose piece of wood trapped between the saw blade and the guide easily becomes a projectile if it slides ever so slightly into the path of the rising blade. You cannot make this cut safely.
So, I used a simple but very effective trick. I carefully adjusted the height of the table saw blade so that it didn’t quite cut all the way through the sides of the box. Each cut left wood uncut about the thickness of a couple of sheets of paper at the top of each cut. The fourth cut was perfectly safe because the top of the box never came loose.
Now, at the bench, away from spinning blades, all it took was a single stroke with a sharp knife blade in the saw kerf to separate the two halves. Once the top was separated from the bottom, I could cut, fit, and glue in the four pieces of ash lining.
The lining, like the outer walls, are end-matched so the grain runs continuously around the box. The lining doesn’t hold the box together, and its joinery can be more decorative rather than structural, so I used a miter. A miter joint consists of two pieces coming together at an angle, usually 45 degrees. It’s an attractive joint that is common on picture frames and other decorative work.
You might think the miter joint is easy, but it is not. It’s difficult for several reasons. It’s quite hard to cut miters to fit. The tiniest bit too long and they don’t fit; the tiniest bit too short and the resultant gap screams “poor workmanship.” They are also very difficult to align because the two angled faces will just slide by each other. They are impossible to glue because a miter joint is always just two end grains. Cutting them requires special jigs or saws that can tilt. I don’t like miters very much.
To make the finicky fitting of the miters easier, I made another custom jig. This time the jig was for my disc sander. It held each piece of the box lining at exactly right angles to the abrasive disc at a precise 45 degree tilt. This allowed me to first rough cut the lining on the table saw, then carefully sneak up to a perfect fit by sanding off a few thousands of an inch of wood at a time.
But the miter joint is the right one for the box lining, and a mitered joint just seems to be a nice complement to the finger joints and rabbets.
The box was given a single coat of urethane varnish, which was wiped off while still wet. This gives the wood some protection without hiding its luster. I signed the box on the bottom with my initials and the year of its construction. In the end, not including the six prototypes made to test various construction methods, I made 51 boxes in four different sizes.
A Box of Four Woods is a celebration and appreciation of wood, a material displaced by plastic and metal but whose beauty remains unsurpassed.
You can see more examples of my wood working (and lots of other personal stuff) on my photo blog.