The Best Oak Money Can't Buy (How to Split Oak)

The Best Oak Money Can’t Buy

 In Feature Articles

The cost of this stock is physical exertion, but it’s fun and rewarding.

By Peter Follansbee
Pages: 38-43

From the October 2011 issue #192
Buy the issue now

The riven oak that I use for joinery work is the best stock available; but it comes at a cost – the labor invested to produce it. Money can’t buy this material; you must split and plane it. But the rewards are many. The oak produced in this manner is unsurpassed, better even than quartersawn stock. Each riven board is perfectly radial, and consequently very dimensionally stable. Straight-grained oak, freshly split, or “green,” works like a dream. The effort involved in splitting and “dressing” the stock is physical, but fun work.

Another benefit of working this way is that you learn a good deal about trees and wood – how they grow, how it behaves. Green wood cuts much more easily than dry stock. Some planning is necessary in scheduling the processes that follow the splitting and planing, but it’s simple enough. In this article, I will outline the steps I go through to produce stock for joinery projects.

The log is key. I look for an oak that is dead-straight, and free of branches, knots or other deformities. It should have a nice round trunk, not oval or misshapen in any way. Crosscut the log between the swelled butt and the first branches. Over the years, I have had success buying logs from a local sawmill; firewood cutters are also sometimes a good source for a log.

If you are not experienced with handling large logs and the equipment to work them, it’s best to work with someone skilled at it. Chainsaws are a great aid to cutting large logs, but are best left to someone who is trained with them. Follow all safety precautions. Oak logs are quite heavy; use levers and other aids to move the log, and to prop it for crosscutting.

Set your log up on spacers, timbers or some large split sections of firewood to get it up off the ground. When cross-cutting, set these supports so that the saw is not between two spacers, but beyond the pair of them. Trying to saw between them results in the log closing in on itself and pinching the sawblade. A pinched saw is not fun. Clear the area underneath the intended cut to avoid hitting debris with the saw. Sometimes it’s best to saw partway through the log, then roll it and come in from the other side to finish the cut.

The lengths of log I work with vary, depending on the projects at hand. For a joined stool or a carved box, I can make the pieces from a log as short as 2′ plus a few inches; for joined chests I need some pieces longer than 4′, but a great deal of the stock is short. All these are approximate lengths. Diameters are critical to the width of the board you will get. I like logs 2′ or more in diameter. Sometimes you can get narrow stock out of a really clear smaller log; but I wouldn’t work with one much under 18″.

Time to Split
For short lengths, as for the joined stool or box, I stand the log up to split it; it’s easier on the back. Score across the middle of the log, right through the pith, or center. You can score this line with the wedges and maul, or use a dull hatchet struck with a wooden club. The idea is to begin to sever the fibers with this scoring.

Then I place a thin steel wedge at each side of the end grain, out toward the sapwood/heartwood demarcation. Drive these in little by little. Light blows of the maul work best; heavy handedness tends to cause the wedges to bounce out of the log. Drive them in tandem. Listen for the cracking sound of the fibers tearing up. Stop hitting the wedges when they still have an inch or two sticking up from the log. The tendency is to bury them all the way in, but if for whatever reason the log does not give up, you can rescue your wedges if you have left an inch or two to strike side-to-side.

Usually by now a split has opened up enough to get a wooden wedge in place; I often locate this between the two steel wedges. As you drive this, the steel wedges come loose. Get them out of the way. Then drive the wooden wedge nearly to its head. By now a split should be running down the sides of the log. You can leapfrog the steel wedges into these side splits, and knock them in. More wooden wedges might be necessary as well. If there are fibers of wood criss-crossed inside, remove the steel wedges, drive wooden ones in to open the log up as much as possible, then get in there with a hatchet or long-handled axe and snip these fibers. Watch for the log falling open when these let go. Shins and feet are particularly at risk.

I sometimes will hew away the bark from the sides of the split; it helps you see what’s happening. I am more likely to do this on a longer log than the short one shown here.

If I can see inside the split and there are no large fibers crossing inside the log, I go ahead to the next step before separating the halves. I score and split one half into quarters. This is easier if the log is still standing. Good straight stock will split reliably in this length.

Aim to always split the stock in halves – this equalizes stress on the log, and it results in splits that run true. Trying to break it into odd sections (thirds, fifths, etc.) usually results in some waste. Sometimes you get lucky, but it takes a really good log. At this stage, I tend to work one quarter, or at most one half, all the way into boards, as shown in the opening picture. I split it out into the desired stock thickness, then dress it in the shop with my bench planes. Leaving the rest of the log in large chunks retains its moisture. This is counter-intuitive to modern woodworking – I want my stock as green as possible for as long as possible – just the opposite of the kiln-dried crowd.

Splitting Into Boards:
Froe & Riving Brake
Sometimes to further split the oak into rough boards I use a froe and riving “brake.” The froe is a wedge-shaped blade, about 10″ to 12″ long, with an eye at one end. The handle fits upward into this eye. In use, the froe is struck with a wooden club that drives the blade into the end grain of the billet. This starts the split. Then you put down the club, and twist the froe’s handle, advancing the split. Shove the froe down to the bottom of the split, and twist again. To distinguish this aspect of the work from the maul and wedges work, I call this “riving” or cleaving the stock, and the previous step “splitting.”

The riving brake is an aid in this step; it is a large wooden tripod with two rails fixed to its front legs (which are about 3′ apart at the height of the crossbars). I like to make my brakes with the bottom rail on the front of the legs, and positioned pretty much level. The top rail is nailed/fixed to the front of the leg on my right, just above the bottom rail. Its other end is angled upward, and fixed to the inside face of the leg on my left. Leave 8″-9″ between them at the wider end. Other rails fasten the front legs to the rear leg. These increase the stability of the brake, and also sometimes give you another spot to brace your workpiece.

The brake allows you to manipulate the split; by exerting more or less pressure you can direct the path of the split – to a degree. Drop a billet of wood into the brake’s cross-rails, standing it up with the thinner end up. Drive the froe into the end grain with the club. Aim to divide it in half, as before. Drive the froe all the way into the wood.

At this stage I put down the club, and pull the workpiece up between the rails, until it’s just about level, and with its bottom end caught in the fork of the rails. Twist the froe handle to continue the split. The rails provide the leverage. If the split “runs” to one side, turn the stock over so the thicker half of the piece is downward. Then exert leverage against that thick half as you twist the froe. This should start to bring the split back in line. Sometimes it is necessary to flip the piece a number of times.

Stock for furniture is usually around 1″ to 2″ thick, and at that thickness the riving is easiest. Slow going is good for beginners. Listen to the sound; with practice you will learn to hear differences in the riving.

Looks Like a Board
So now the stock should be radially riven to an oversized thickness and width; and it begins to look like boards at this point. The bark and sapwood must be removed before you can work it in the shop with bench planes. For this step, we purposely sidestep the rule about always splitting in halves. I usually use the froe to knock off the sapwood and bark. Drive the froe just inside the area of sapwood, then twist. Most likely, your split will run out. Come in from the other end and repeat. With the joiners’ hatchet (broad hatchet, hewing hatchet, side hatchet – it has a lot of names) hew away any sapwood that remains.

Hewing is something new for many furniture makers; it is very rewarding work, but there is a degree of finesse involved. You don’t just go hacking away at the wood. First, consider the shape of the tool – the hatchet has only one bevel. Mostly flat on its back, it has a slight scoop along the cutting edge, and is fitted with a short handle, which is held in one hand. You will also want a large hewing stump (also called a hacking stock or chopping block). Mine are about 20″ diameter or more, and about 24″ high. I keep one or two outside where I break open the logs, and another in the shop. Keep the surface of the stump free of debris, otherwise the hatchet’s edge is dulled quickly.

Posture and stance are important. Hold the stock on end, positioned across the stump from you. I lean the stock a little, and the action of the hatchet is plumb, or perpendicular to the surface of the stump. I’m right-handed, so I drop my right leg a good bit behind me. This serves two purposes. The first is with my feet spread apart like this, it makes a more stable base from which to work. Second, with my leg back out of the way, an errant blow from the hatchet is less likely to make contact with my body.

Make relief cuts with the hatchet to a visual line just inside the sapwood. You can strike a chalkline, too, if that helps. Use a light chopping action. Start at the bottom and work upward about three-quarters of the way up the stock. Stop before you get close to your upper hand. Now straighten the stock up, and keeping the hatchet in the same path as before, swing it lightly to remove the stock you have scored with the first cuts. Removing sapwood this way is good practice for actually hewing the finished surface as preparation for planing.

Next comes dressing the stock into boards. For this work, I usually move into the shop, where I work at the bench and stump. Check each radial face to see which is best. We are looking for whichever face is closest to flat with no twist, no bow or hump. If there are problems, use a hatchet to remove the bulk of excess material so that planing will go more quickly.

Get Ready to Plane
There are many methods for holding the stock for planing. I will describe the bench I use; it’s based on 17th-century engravings to a large extent. I use a “bench hook” – a 17th-century term for a toothed iron planing stop set in a wooden block in the bench. Raise or lower the bench hook so that it catches the end grain of the workpiece, but make sure it’s low enough so the plane iron doesn’t hit it. I just shove the workpiece into the teeth of the bench hook. I sight down along the top surface of the stock to check for wind or twist and other deviations from flat. While there is no 17th-century evidence for winding sticks, I find them quite useful. You can make them from two pieces of very straight-grained stock. Plane them to an even width. Check them against each other to ensure that they are straight. To use the winding sticks, set one near each end of the board, crouch down, close one eye and sight across them. If their top edges both lie in a plane, then the board is not twisted. If thereis a twist, the winding sticks will readily reveal it. Then the first strokes of your planing will be aimed at correcting this twist.

Fore Plane
The first plane I use is a “fore” plane – similar to a “scrub” plane these days. The one thing both these planes have in common is the shape of the cutting iron, and the thickness of the shaving they are set to cut. The cutting end of the iron is a convex curve, sometimes quite pronounced. The shavings are thick, to quickly remove as much stock as possible. There is at times debate about the proper length and width for these planes. I think there is a great deal of leeway here. I prefer a wide plane for this work. I find it more comfortable to handle than the narrow planes commonly sold as scrub planes these days. Mine are usually shorter (about 8″-10″) than what we think was used in some 17th-century contexts. Some of my fore planes are German smooth planes that I reground to a convex iron. I sometimes throw away the cap iron and make a new wedge for them while I am at it.

The aim for this planing is to remove the bulk of the material, in preparation for finish planing the surface. The green wood shaves with remarkable ease. The fore plane can be used in line with the grain, or directly across it, or anywhere in between. At this point, the condition of the surface is of no concern. Check frequently with winding sticks and a straightedge to be certain of your progress. The planing strokes head toward the bench hook. I often am shuffling the workpiece this way and that so that my plane aims for the hook. If the stroke does not aim for the bench hook, the workpiece can whip around and go skittering off the bench – not a problem unless someone is watching, or is in the line of fire.

Jointer Plane
If the stock is really the best quality, my next step is to plane it with a jointer plane. A fine shaving is all I want; the gist is to smooth and flatten the stock, and remove the marks from the fore plane. The wet wood planes quite easily, but it will not take the best finish right now. The main goal at this stage is to produce a nice flat face that is as smooth as the stock will allow at this point.

I next strike a chalkline on this face, near the edge where the sapwood was removed. This edge is easiest to straighten. I trim the edge with the hatchet, then use the jointer to plane it nice and even. To secure the stock for planing the edge, my bench has two options. For some short stock, I secure the end of the stock in a double screw – a pair of wooden cheeks fixed to each other with large wooden screws. This keeps the stock up on edge, then I jam its forward end against the bench hook. For longer stock, I fix the piece in the single screw on the bench’s edge. This sometimes requires its other end be propped up on a peg in a sliding deadman.

Now with the face and edge done, I mark the thickness on the planed edge; use either a chalkline or marking gauge. Depending on how much thickness needs to be removed, you can rive some off with the froe, this time employing the tendency for uneven splits to run out – otherwise you can hew off the excess or plane it with the fore plane.

That’s a lot of options, but over time all of these techniques are employed, depending on the specifics of each board. I try to work the boards down to rough thickness. Sometimes the rear face is only worked to the fore plane stage. Frequently I will leave the second edge for later. These riven boards often taper in width as well as thickness, and sometimes I can’t decide what width I need until I have a project in mind.

Now Wait
The surface you plane in dead-green stock like this is excellent, but not the best. There tend to be some fuzzy qualities to it. Before I proceed further, I sticker the boards in the shop, and let them sit for a while. How long depends on several factors – the relative humidity in the shop is the most critical. Winters in my shop are dry with the heat on; summers are humid with the windows and doors open. So stock takes longer to settle down in summer than in winter.

If the room is too dry, you might want to seal the end grain of the boards, particularly with thicker stock like that for the stiles for joined stools, and chairs and chests. I use yellow glue; I often have it around the shop, but only rarely use it as an adhesive. Thus mine goes bad before I finish the bottle, so I don’t mind using it for this. Dedicated sealers can be found as well. Latex paint can work, too.

The heavier stock I even bury in a pile of fresh shavings for the first few days. Then I sticker it in a pile (away from any heat source or sunlight). I find that white oak is trickier to dry than red oak. Thick (2″ or more) pieces of white oak often want to check on the end grain, or even along  the tangential surface. Burying them in shavings for a while first often is enough to slow down this drying.

Take them out now and then to look them over. Slower is better; this is not to be rushed. Stickers provide air flow between the boards. If you stack the boards without them, mold will form on the faces of the stock.

When I am really organized, and working a lot of boards at once, I often write the date on the end grain. This makes it easier to keep track of a lot of stock.

Smoothing Plane
After the boards have sat for a while (roughly two to four weeks) I can then take them from the stack, and with a sharp smoothing plane, re-plane the surface. We’re just talking about a few strokes to clean up any torn, fuzzy fibers. The surface of the stock has dried enough now to take a finer finish cut with the plane; but the interior of the stock is still moist. Thus cutting is still easier than it would be on kiln-dried stuff. Now is the time to carve decoration, cut joinery, and do any turned work for the project at hand.

When things go really well with a log, I end up with stock prepared far ahead. If it gets drier than I want, I reserve it for boxes, panels in joined work, some framing parts, etc. I store it on shelves up on edge so I can easily see the width of the stock. In this pile, it needs no spacers between.

That’s about the run of it. It sounds like more work than it is. As with any handwork, with practice you end up making various critiques and decisions as you work the stock; it needs to be thinner here, wider there. It is an ongoing culling process, making boards directly from logs. But you won’t get better stock anywhere – and by the time it gets to your bench for a project, you’ll know that board backward and forward. PWM

VIDEO: Watch bodger Don Weber split a log.
BLOG: Read Peter’s blog on period shop practices and joinery.
TO BUY: “17th Century New England Carving,” a new DVD from Peter Follansbee.
IN THE STORE: “Mechanick Exercises” by Joseph Moxon.

From the October 2011 issue #192
Buy the issue now

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