Ancient Bog Oak: Furniture 2,000 Years in the Making

Staked table and lowback stick chairs in bog oak.

The following is by Andy Brownell of Brownell Furniture.

As a part-time furniture maker, I’ve been lucky enough to have two good things come my way by living in Cincinnati. I’m a 20-minute drive in one direction from Lost Art Press and in the other from M. Bohlke Corp., a Greater Cincinnati lumber and veneer business with just about every possible option for wood under one roof. This post is a mash-up of those two forces coming together and some furniture projects using a rare and very special boule of bog oak.

Listen beautiful relax classics on our Youtube channel.

Introduction: Tree History & Terroir
It’s 153 B.C. and somewhere in the region of modern-day Poland, you’re standing in a mixed decidious forest. The population of the area is a mix, and possibly has some interaction with the far reaches of the Roman Empire and the Celtic people through trade, war, sex – or some combination of all three – for hundreds of years. Signs of human occupation are everywhere: agriculture; timber-framed buildings; metalwork; ceramics; woodworking; even the forest clearcutting that comes with human occupation throughout the world. As a result, wood remains a coveted resource, whether you’re a Celt or Roman. Small, unprotected villages of a few dozen people dot the landscape, and there are signs of trade.

The iron age Przeworsk culture from this region of Poland was a material-rich society of organized farmers, and was probably an amalgam of people from other parts of Europe and beyond. The oak tree (European oak) throughout the forests was as formidable then as it is now. In Celtic culture across this region it was considered sacred, being endowed with strength, endurance and longevity. 

For one European oak somewhere in the range of 150-175 years old, it’s time had come. Whether through an act of human intervention, mother nature, or from an axe blow by the Gaulish god Esus, the tree came down and was soon engulfed within a bog. It then sat ensconced within a dark, wet and silty coffin. This unique set of factors resulted in the creation of an anaerobic (low oxygen) environment, so rather than rotting and decomposing, most of its main trunk (the “first cut”) sat undisturbed in the bog for millennia.

A thumb-sized sample sent to a radiocarbon dating lab came back with an approximate age of 2,175 +/-25 years.

To make the story more interesting, I wanted to know how old this particular oak – identified as European Oak, aka Quercus robur, by M. Bohlke Corp. – was. So I sent off a small sample to a radiocarbon dating facility in Georgia. Three weeks, and $350 later, the results were in: 2,175 +/-25 years. You can see the lab facility’s report here if you want to go down the rabbit hole.

Over two millennia, the tree slowly absorbed the black ooze of the bog’s organic and inorganic matter. It filtered past the outer bark, cambium and sapwood, all the way into the heartwood of the tree. This is something akin to the process of “permineralization,” an early stage of petrification, where silicates from the soil begin to replace the organic matter of the wood. The soil’s chemistry interacts with the tannins in the oak much like they would on modern oak. But as this iron salt-rich ooze permeates the complex grain and cell structure of the European oak, the wood takes on a spectrum of color that only time can produce.

The full boule sitting at the warehouse of M. Bohlke.

Color & Material Properties
The sediment absorption and the color it leaves behind is like if you were to over-filter the same coffee beans for a shot of espresso, over and over. Each cup would get subsequently weaker and weaker in both color and taste. The log is darkest on the outside and gets lighter as you go in. Going a step further with the coffee reference to describe the color of the wood, it starts out as a charcoal-black burned espresso, has hues of an olive green matcha, then into golden crema and latte. At the heart it ends up as a weak cup of Sanka with lots of creamer served up in a flimsy foam cup. The Sanka-grade material of this boule was where much of the waste came from – and it resembled flimsy foam. It also had some white fungal-/spore-looking rot in the heartwood and in some splits that caused an allergic reaction in at least one woodworker I know. Hmm…ancient white spores released into the air causing a reaction in humans: sounds like the back story to “The Last of Us.” Mask up.

The spongy, moldy, ancient spore-riddled heart of the tree.

This color spectrum appearing on the highly figured, quarter-cut pieces of the boule produced the best-looking stuff (think tabletops and seats). Other bog oak logs can take on a charcoal/burned espresso color through most of the log. There are plenty of examples online where you can see that the really dark ones are dated up to 10,000 years old. Only the outer cant of the boule I purchased has this color throughout.  I presume this is based on the total amount of time the log stews in the bog, as well as the physical environment, etc. As far as color goes, I’d place this bog oak log in a class all by itself. There really is no comparison to any extant wood species out there. 

Flaked grain and a full color spectrum of bog oak shown finished here on the best quartered boards.

But don’t get too caught up on those coffee metaphors, because bog oak has a few extra surprises in store for the woodworker. The bog’s organic material carries a rich mix of methane and sulfur-rich compounds. So cutting with any high-speed tool releases the funk from 153 B.C.E. A bit of rotten egg, perhaps? Chris and Megan claim a hint of turtle poop, but I wouldn’t know that scent. The piquant odor takes me back to when I was a kid living in Rhode Island, mucking through the salt flats with my brother at low tide for little necks and quahogs. The smell sticks to your nose hairs and brain, like burning hair or toast.

Of the dozens of domestic and imported wood species that I’ve worked with over the years, I’d place bog oak’s scent just below fumed eucalyptus and bubinga, but riper than teak.

In the words of Vincent Price at the end of Thriller: “And rot inside a corpse’s shell/The foulest stench is in the air/The funk of forty thousand years….”

The grain and its associated workability is in most cases similar to modern-day European Oak. This is based on my experience with this log as well as some European oak from the present that I have also used for a few projects in the last few years. For my hand and power tools, including turning, I didn’t notice anything dramatically different with this bog oak compared to other oak. I did have a few pieces that when ripped to around ¼” or less were almost malleable, like Compwood, or that foam cup I mentioned earlier.

Handplane shavings of many colors.

Right Project, Right Log
Back in early 2022, I met with a prospective client, their interior decorator and the Bohlke team to look through their log inventory. The client was looking for something unique to fill the dining space of their new home, and loved the beauty and story that came along with bog oak.

The boule was about 14’ long, 35” at the base, and tapered to about 22’ at the top. Most of the 412 total board feet was cut to a generous 8/4 thick, with a few of the outer boards cut to around 5/4. This was one of a few bog oak boules available from Bohlke. While the project didn’t require the full boule, it was sold as a full boule, and I wanted to use the rest of the log for a kitchen table and chairs project later in the year.

Board selection and break-down required my full two car garage, and losing my space during the winter.

The first project I tackled was for a client’s new 116”-long dining table (extended with two “company board” leafs). I set aside about half the boule, and cherry-picked the best quartered boards with plenty of straight grain and lots of flake. 

As luck would have it, I was fortunate enough to have this entire table project filmed by a local production crew, Seven/Seventy-Nine, over the course of several months. If you’re interested, you can see the entire process here in a short video called “Small Shop.” It’s worth noting that this project, particularly the grain orientation and color selection from the tabletop, served as a proof of concept for how I would lay out a second tabletop for our kitchen.

The first project I tackled with the bog oak was this 116″ long dining table.

It’s this part of the bog oak story with which most of you might be familiar. Anything this big, old and rare often comes at a premium, so I was thrilled (as was my wife) to split up part of this boule with Christopher Schwarz. Chris has spent the last year working through his portion, making a number of different chairs. Like many followers of Lost Art Press, I became envious of how amazing those chairs looked when made from such a unique material, especially the deceptively comfortable low-backs. Seeing one in person, it was love at first sight. You want to both sit in the chair and stand up and touch the shape and details. 

Learning the Basics: Two Comb Back Chairs in Maple 
As a part-time furniture maker since 1996, I haven’t built many chairs – perhaps a dozen total. In the last few years, however, and with some encouragement from Chris and my friend and mentor Jeff Miller, I’ve really tried to get into the act. Over the last year, I’ve been learning how to make stick chairs between some of the other commission projects I’ve taken on. Like other students of the stick chair genre, this has been through a combination of LAP’s books, The Stick Chair Journal, blog posts, and some extremely helpful, in-person instruction and second opinions with Chris. My 20-minute drive to the LAP shop was particularly helpful while making my first two comb-backs out of maple. Chris talked me off the ledge and helped bail me out with a repair on an arm I split pretty badly during glue-up and assembly. It went back together with plenty of clamps and some Miller Dowels for additional mechanical bonding. I had always planned to paint the two comb backs black, so the repair is virtually invisible.

A broken arm occurred during glue up. Plenty of clamps, and reshaping, solved the problem.

Social media trolls aside, every furniture maker is their own worst critic. Looking at the two comb backs side by side, I can definitely see some of the inconsistencies and small mistakes, mainly on the rake and splay of the legs. Even with a laser to help guide my eye, I found that the most difficult part of this project was drilling straight and even holes and tapers in the seat bottoms. I found that the long shaft of the drill bit would bend and wobble slightly under pressure, and take me off track as the spade bit hogged through the maple. I’m glad I practiced on the maple before cutting into the bog oak. In the end, I applied the skills and techniques picked up while working on these two chairs, then used what I learned on four lowbacks.

Listen beautiful relax classics on our Youtube channel.

My first attempt at stick chair building – far from perfect, but perfectly suitable for our home office. Plus, paint makes it all look better.

Four Low Backs
I’m a perfectionist when it comes to color and grain matching of furniture parts. But making chairs from two-millennia-old wood forces you to make some compromises in the interest of using as much of the material as possible. However, even with the noble intention of not wasting any, I’ve already sent 60+ gallons of offcuts to my neighbor’s burn pile. 

The lowback seats and backrests are the two primary areas that the eye goes to on these chairs, so my type-A tendencies really kicked in during this phase of the project. On the seats it was relatively easy to get a good match of grain and color, even with the high contrasts in the bog oak. These were all cut from sequential pieces of 8/4, and gave me some really smoky edges that showed off the dark rich grain from front to back, especially after being carved out.

The challenging part of grain selection with a highly contrasting wood like bog oak is most evident in creating the parts for the back rest.

I also made a three-piece arm, modeled after the version in The Stick Chair Journal No. 1, rather than a two-piece lower section, as described in “The Stick Chair Book” plans. This dramatically reduced the amount of waste for this part, and allowed me to resaw the 8/4 to make perfectly symmetrical bookmatched arms for each chair. 

The backrest presented an interesting challenge, however, because the radius cuts a generous curve into the two segments that are glued up to form the back section. I went into the layout with good intentions, picking the darkest parts of the tree. But after cutting out all four backrests, I ended up with three highly varied degrees of grain and color matching. Not perfect, but I ended up justifying the result by claiming that each one has its own personality – from “creamy” to “burned.” I guess I’ll assign those to my dinner guests corresponding to their own personalities. The lesson here is don’t try to get too fancy with the back rests, and pick the most consistent color and grain possible.

Four lowback stick chairs in bog oak, arranged in order of light to dark.

Staked Table on Steroids
Having made six stick chairs at this point, I wanted to apply some of the new techniques I learned to the table. I also wanted to have the chairs and table look like they were intentionally designed as a set. I love round tabletops, but don’t get many commission requests for that shape. Also, our kitchen remodel had an open floor plan, so I decided on a round top that would take up less room and make the flow from one room to the next more subtle. 

The six-piece top measures 60” x 1-1/2″ thick; it came from three sequentially matched boards closest to the center of the log (for the most ray flake). I cut them in half lengthwise then arranged in a bookmatched orientation similar to the arrangement on the first dining tabletop.

Shaping a large tabletop by hand had a Sisyphean feel.

The legs are made from two laminated pieces of 1-3/4” x 3-1/2″ stock, which gave me 3-1/2” square blanks to work from. For the table legs, I opted for hexagonal legs, which gave me more visual mass from less material than the octagonal legs on the chairs. The points of the hexagon help hide the lamination lines and, after cutting the blanks, I struggled to identify where the two pieces were joined.

I took time to dial in the color and grain match for the two-piece laminated leg blanks.

After cutting the hexagonal blanks on the table saw (see The Stick Chair Journal No.1 on cutting hexagonal legs from rectangular blanks), I marked the centers on each end to lay out the tenons. Next, I turned 1-3/4”-diameter x 3-1/2”-long tenons, including a quarterround cove to mark the shoulder transition. This was essentially the same process as turning the parts on the chairs, only scaled up. Later, I also used the band saw to cut slightly thicker kerfs on the tenons in order to accommodate for the beefy wedges during glue-up. Finally, I tapered the legs on the jointer – much like how they were tapered on the chair legs, there’s just more material to remove. So by marking layout lines on the facets for the tapers, and adjusting my jointer’s fence to 30°, I was able to sneak up on the line with multiple passes. (image)

The legs with tenons, flats and coves at the transition point.

The low-profile underside of the table is made from four, 6”-wide x 1-3/4”-thick boards reinforced with solid corner blocks that accommodate for the large mortise-and-tenon joinery of the legs. The table legs have an 8° splay from the corners along the 45° axis, with ends that sit far enough in from the table edge for the chairs to be pushed in most of the way under the top. I drilled these out on my drill press with a beefy 1-¾” Forstner bit (with threaded tip, and a rudimentary 8° plywood sled to help hold the frame rails in place during drilling. (image)

I drilled the mortises at the drill press.

The other modification I made to the leg assembly was the addition of a wide, flat shoulder around the mortises to allow for the most contact possible between the shoulder of the leg and base. (image) I figured this would give the sub-assembly the best possible mechanical connection to support the weight of the tabletop. I did this by making a rudimentary router template, sloped at 8°, and used a straight bit with a bushing to make a clean, consistent cut. The flat contact between the legs and base, along with some wedges, made the glue-up and assembly go smoothly. (image

Both the legs and table base have flat points of contact.
Leveling the table base and cutting the legs was exactly the same process as the stick chairs, minus the slope in the seat.

Finish & Final Photos
For the chairs, I used two coats of Katherine’s Soft Wax 2.0. Having seen in person what this finish looked like on some of Chris’ bog oak chairs, it was an easy decision to make. For the table I needed something a bit more durable and something I’ve had consistent results with in the past. So I applied three coats of Minwax oil-based wipe-on polyurethane (satin finish), then took the sheen down after the finish was cured with a fine grey Scotch-Brite pad. I know some people will give me crap about applying a “plastic” finish to this ancient wood, but it’s what I like and it is easy to apply by hand in my small shop. For my tables, I prefer to not sweat it over a dinner guest’s sweaty glass, spilled food or hot plate. You’re free to use whatever finish you choose on your own table made from 2,000-year-old wood. (Click here to see a video of the table and chairs.)

‘It’s not the destination, it’s the journey.’
I think the Ralph Waldo Emerson quote above best summarizes my experience. And while I still have about 75bf of bog oak remaining, the many branches my journey has taken with this wood have been the best parts. I was incredibly fortunate to be able to work with ancient and rare material. This included a commission project from the start that was big enough and a client willing to use bog oak, and a local supplier where I could get the material in the first place. I went down the history/science rabbit hole of bog oak, so I learned lots of interesting new facts. With the addition of the radio-carbon dating to the story, it added some authenticity to the unique nature of these pieces. I added new skills to my woodworking repertoire, with plenty of mistakes along the way. But I got in my reps, and improved my technique across six chairs and two table projects – not to mention these builds provided a good excuse to buy some new handy tools. Sharing this experience with the Lost Art Press team reconnected me with old friends right in my own backyard. Throughout the entire journey, I’ve documented the process in photos, video and now in the written form. As a professional creative and content producer, this work makes me better at my full-time job. (Remember, woodworking is my side hustle. My full-time job is with the OneSight EssilorLuxottica Foundation.) Building these pieces has enriched my life as a creative and storyteller. It fed my natural curiosity of ongoing learning as a furniture maker and lifelong student of nature, history and science. 

– Andy Brownell, July 2023


No votes yet.
Please wait...