Medieval Woodworking Part 3: plank chest 1

One down. At least three to go. The list of projects for this demonstration gets longer every time I open a book. With the workbench finished I’ve turned my attention to some ‘flat work’. Staked stools and demonstration tools  can wait. There are at least three chests I’d like to build for this: a Viking piece based on the Mastermyer chest, a clamp-front and this project.

I’m writing this half way through building  it and have I realised that I’m going to have to do it twice. Once to have a complete chest to show and then again to demonstrate the process. Fortunately it’s about as easy as furniture construction gets: a ‘six board’, ‘six plank’, ‘slab-end’ or just ‘boarded’ or ‘plank’ chest. Six bits of wood and some fastenings.

I’ve taken the opportunity to try a variety of techniques. There are several surviving chests that use pegs and at least as many that are nailed from around the period we’re interested in. Copper rivets1 were also in use and since I’ve got plenty kicking around from boatbuilding projects I’m hoping to squeeze some in. Two chests may not be enough.

Marhamchurch plank chest on white

A starting point: riven oak late medieval plank chest. Courtesy of Marhamchurch Antiques.

This chest will come from a single rough-sawn board. It is definitely a small chest;  height and depth are dictated by the available timber. The inspiration for this piece is from two different chests (above and below) that have been sold by Marhamchurch Antiques in Devon. They’re a bit later than the period we’re interested in but the only strong sign of this are the trefoil arches on the first chest that form the feet. Other than that either could have been built hundreds of years earlier.

Marhamchurch flat sawn chestSix board chests are built with simple construction rather than longevity in mind. The grain on the sides is perpendicular to the grain on the ends. The movement of the timber will eventually cause the fastenings to loosen and the boards to split. Despite this many survive because there are ways around this:

  • Version 2Keep it small. The narrower the long planks the less movement there will be and so the fastenings are more likely to be able to resist the seasonal changes and the  boards won’t split. I estimate that the front board from the riven oak chest from  Marhamchurch Antiques is about 18′ high and even in riven stock that creates a lot of movement causing a split near the bottom.
  • Build it from cleft (riven) or rift-sawn stock. Movement across the grain in the tangential plain (at a tangent to the growth rings of the tree) is twice that in the radial plain (a straight line going from the middle of the tree to the bark). Radially cleft, or riven, timber was common in Anglo-Scandinavian England2. This means that the pieces will inevitably be narrower than flat-sawn panels and the movement will be significantly reduced. You can see this in the first chest to the right but not in the second which appears to be built of flat sawn boards. In the second chest the sides may have shrunk away from the notches at the bottom leaving a gap. In the first they have not.
  • Marhamchurch flat sawn chest strapsUse metal straps. Many surviving large six board chests have substantial metal reinforcements. However a lot of these are ecclesiastical pieces or come from the estates of powerful and wealthy individuals. They are not the focus of this demonstration. The second chest from Marhamchurch compensates for its flat sawn grain by reinforcing the joints at the top. It’s hard to know whether this was done at the time of manufacture or later as the joints worked loose with the seasons. The position of the strap over the nail and the difference between the two nails suggests the latter.

The design of this chest is dictated by the timber. Though the Egyptians had glue thousands of years before this time period I can find no evidence that the Anglo-Saxond or Anglo-Scandinavians did. Even if they did it was animal glue and would have faired poorly in the damp. That means that wide panels made up from a number of boards were not used. The front of a chest was as long and as high as the planks as the widest board you could get from a tree.

Forklift and boardTime spent picking through boards at the timber yard is well rewarded. (And so is being nice to the man with the huge forklift. I learnt a lot from him that day.) I wanted to select wide stock with vertical grain. Access to large-diameter fresh cut oak is rare so riven stock is out of the question and that left me searching for the widest boards sawn from the middle of the log.

With a newly commissioned low bench sitting in the garden I started by trying to work the boards to their final dimensions in a manner that might be familiar to a medieval joiner. Sawing went well. It’s little more than a giant saw bench and I’m comfortable using it as such. Heavy planing was more of an issue. Bent forward, pushing a plane with just my arms was hard and uncomfortable work. When standing at the traditional joiner’s bench many more of my muscles help out. The much bigger and more resilient muscles of my legs do a lot of the work.

Frustrated and realising that I would wake up the next day aching and with much less work done than I had planned I went back to my familiar friend – the joiner’s bench. There is plenty of time to play with the low bench between now and the  demonstration.

Stickered oak.jpgI planed each piece to just over 3/4′ leaving a little spare to remove once the boards had moved a little more. A couple of weeks in stick and they were ready for joinery.

This gave me a bit of time to decide on fastenings. Chris Schwarz3 asserts that nails are the the secret to surviving chests’ longevity. They “allow you to get away with serious crimes of wood movement… a nail will allow the wood to expand and contract, bending back and forth through the yearly humidity cycles.” This also means that they will loosen over time. But it’s the best of a bad job.

Dowel plate

Not a medieval dowel plate. Its laser cut descendant.

Nails were made by blacksmiths, each one hand forged. So if a joiner wants to join a chest with nails s/he must buy (or trade for) them. But a dowel plate is a one-off purchase and then you’ve got pegs for life.

There aren’t enough extant medieval plank chests to be able to draw a conclusion about what was used more – pegs or nails – but in the interest of self-reliance I’ve used the trunnels for this chest.

Next time: joinery.

 

1. “Radially split offcuts of other species include… an alder fragment with 30-40 copper alloy rivets embedded in it…” Morris, C., Wood and Woodworking in Anglo-Scandinavian and Medieval York p. 2221-2223
2. “Most conversion of wood for artefacts was done by radial splitting…” Morris, C., Wood and Woodworking in Anglo-Scandinavian and Medieval York p. 2104
3.

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Treenails

Several of the chests I’ve used to inform this demonstration have been put together with treenails (trenails/trunnels/pegs etc.) I’ve used pegs for drawbored mortice and tenon joints quite a lot. A dowel plate is traditional for pounding them to shape and I’ve had some success with this method. It’s noisy work and sometimes I don’t get the straightest pegs but it does have one structural advantage – the pegs follow the grain of the timber.

IMG_0795Last summer I visited the Viking Centre near Ribe in Denmark. I was delighted to see them using an identical method but for much larger pegs. Their living history exhibits draw on a substantial body of research and I’m assuming that there is evidence that this is historically accurate. I’d welcome your corrections if I’m wrong.

However I rarely use the plate anymore. For this task I’ve chosen the “workmanship of certainty” over “the workmanship of risk”1. Partly because it gives more consistent results, partly because it’s a lot quieter but mostly because I get to use a really great machine!

Pegs through scarf

Boring the holes at an angle draws the scarf together. So they say.

In the interests of full disclosure: some of the treenails used in this chest will be pounded out by hand in a thoroughly medieval fashion but most of them won’t be…

1. Pye, D. 1968 The Nature and Art of Workmanship

Medieval woodworking part 2

If I’m to demonstrate C13th woodwork I’ll need a bench. There’s no evidence, as far as I’m aware, that the waist-high joiners’ benches we know today existed in those time. Staked benches, both low and high, certainly did.

Once again Chris Schwarz’s Roman Workbenches and Vires’ Woodworking in Estonia provided some inspiration, measurements and guidance.

I’m not making any great claims to historical accuracy with this. It’s a fairly pragmatic step. People almost certainly sat on low benches and removed small bits of wood from bigger bits of wood. They still do. We’ll get to the interesting stuff (chests and chairs) soon but in the meantime here’s what I built:

 

Use the tool in your hand


My carving teacher used to admonish me to do as much work as I could with the tool in my hand. Carvers often have a lot of tools on their benches. Swapping between them uses time. Use the tool in your hand until you can do no more work with it, then change.

I’ve just cut 13 brackets for a chest. They each have two ends with five edges at each end. That’s 130 edges. I started by using a block plane (an old Record 018  in case you’re only here for the tools!) for the straight edges and a chisel, bevel down, for the curves. The block plane wasn’t gaining me anything. The straight edges are so short that keeping the plane flat and the cut even was as much effort as doing the whole thing with a chisel. So I did.

If you’re paring end grain chamfers here are some notes.

  • Pare along and up, never down.
  • Always pare towards an already chamfered edge. That’s what the first corner cut is for.
  • Bevel down on concave curves.
  • As always – a very sharp chisel makes this a lot easier.
Fold-down bedside cabinet

Fold-down bedside cabinet

Fold down bedside cabinetMost of my work starts with something I’ve seen: a plan, a boat, a piece of furniture, a lump of wood with something hiding inside it. This project started with an empty space.

The space was eight inches deep, two feet wide and eight feet high. Somewhere in it I needed to put a cabinet that would hold a couple of books, a phone, a glass of water etc. All the things  someone wants by their bed. But eight inches makes for a very odd cabinet.

I had no starting point. I’ve never seen anything like the thing I needed to build. Somewhere in a corner of my brain this was lurking:

foldingsinksm I had seen a folding sink at a boat jumble. It was in horrible condition but an interesting relic of a bygone age. This drawing is from Shipmate who are planning to start producing them again. Things are looking up.

I love metamorphic furniture. Kenwood House is a healthy walk from my house and has a few pieces including library stairs and a folding desk you can stand on to get books from high shelves.

Ideas were colliding. A plan wasn’t exactly starting to take shape so much as coalesce.

The design wasn’t based on beautiful proportions or the rules of classical architecture. It was based on how tall a glass is, how thick a substantial novel is likely to get, what height is convenient when lying in bed and how thick flush-fitting hardware is.

I had to consider proportions, of course, but I tried to keep the piece as small as possible and as large as necessary. When all the requirements were laid out on paper it started to design itself. My biggest decisions were how thick to make the frames and how to lay out the grain on the shelf and panels.

Once the design was finished it presented some very diverting joinery: lapped and through dovetails in the drawer, mitred dovetails in the shelf, tongue and groove joints to hold the carcass together and mortise and tenons in the frames. The panels are rubbed joints in very thin stock. Lots of fun.

Overall I’m happy with it. There are half a dozen things I’d change if I were starting again but the client is happy and therefore, so am I.

Arched lid mock up

Arched lid mock up

The technique seems to work. I glued up pairs, then fours and finally the seam down the middle. This photo shows a bit of flattening at the top. I had to replane the edges for the last joint; clamping had given them a bit of edge set and I needed to true them up. In doing so I lessened the bevel flattening the curve.

A useful lesson learned. I’m glad I did this on scrap.

Another lesson I seem to need to relearn is to pay attention to grain direction better. While planing the planks to give a smoother curve I was reminded of the need to match the grain direction in adjoining pieces by big chunks of tear out. That said, these oak planks found their way to the bottom of the wood rack because they had such convoluted grain. None of the pieces here have consistent grain along their length.

The Douglas Fir arrives in seven days. I hope it’s more consistent. I didn’t get to pick the planks myself.