by Daniel Diehl
Banding
Allow several extra inches of metal when creating hinges or bands that extend around the sides of a piece of furniture. Some of the length will disappear in the act of bending the metal at the corners. Be patient when banding a furniture case; bend one corner and fit it into place before marking the position of the next bend. Heating and bending alter the length of the metal stock in unpredictable ways.
Forging Tip
To distress the smooth exterior of metal bar stock, lay it on the vise or an anvil and heat 3 to 4 inches of its length at a time with the torch, marring the surface and edges with the round end of your forging hammer. Eliminate the regular edges of the metal, but do not distort or misshape the stock.
Lock Plates
A lock plate or escutcheon shields the area around the opening in the wood through which the key is inserted. Escutcheons are usually constructed of 1⁄16-inch-thick flat stock, far thinner than the hinges and bands on a chest. Patterns for lock plates accompany the furniture drawings. These can usually be cut out of flat stock. Heat the edges, distress them slightly, and file smooth.
Nails
Applying hinges and hardware requires fairly large quantities of handforged nails. Simple cut nails lack the large heads necessary to secure the hardware. Medieval nails were often longer than the thickness of the wood into which they were driven. The expedient solution to this problem was simply to curve over the end of the nail on the interior of the chest, which also added strength. Such nails were called clinch nails. Some modern reproduction forged nails are too brittle to bend without breaking; if you are unsure whether they can be clinched, experiment on a scrap of wood. It is technically possible to make nails by hand; we commend your persistence if you do, but we don’t recommend it. Rather, purchase nails of the right size, length, and head style from a supplier of reproduction nails (see the Sources section on page 321).
Metal Finishes
To give a uniform dark finish to your newly fashioned metalwork and prevent it from rusting, we suggest a natural oil finish. There are two ways to finish metal objects. The first is to clean the forged metal thoroughly with a wire brush, and then coat the surface evenly with olive oil—the same substance often used as a finish on medieval woodwork. Apply even heat to the metal for 30 to 45 seconds with either a torch or a kitchen stove. Heat it just to the point where it cannot be touched. Blacken the oil; do not burn it off the metal. Allow the metal to cool naturally, and wipe it with a clean, dry cloth.
The second method is not dissimilar to the first. Fill a large metal pan to a depth of 1½ to 2 inches with heavyweight oil—used motor oil is perfect for this purpose. Heat the metalwork with a torch until it is hot but not glowing. Quench the hot metal in the pan of oil. Wipe the excess oil from the metal.
Locks
The mechanical lock has been used to protect the contents of chests, cabinets, and trunks since the early Middle Ages. Since the tenth century, they were common enough that even the Vikings routinely installed them on their sea chests. The design of these early locks was so successful that, except for minor refinements, the standard domestic lockset remained almost unchanged until the end of the nineteenth century. Almost any lock that can be operated with an old-fashioned skeleton key is based on the same design as the medieval lock.
Sadly, virtually all the locks that originally protected the contents of the chests and cupboards shown in this book have been removed or replaced. Medieval locks are somewhat rare because the delicate mechanism of a lock can easily fall victim to rust and corrosion. In many instances, heavy, surface-mounted hasps or simple wooden turn buttons have obviously been retrofitted to pieces of furniture that still have a lock plate that once covered a lock.
There are two possible approaches to equipping medieval furniture with working locks. The first, and by far the better, is to reproduce a medieval lock; the second is to adapt a newer lockset to the piece of medieval furniture. If you opt for authenticity after investing so much effort in your chest or cabinet, follow these instructions to re-create a medieval lockset. Although locksets are relatively simple to build, their limited technology leaves their security factor lacking. (Translation: These locks will keep honest people honest, but they won’t keep out the bad guys for long.)
The instructions provided here are for a lockset adapted from a number of surviving period locks. Although the mechanism is extremely simple, pay careful attention to both the drawings and text to understand the lockset well enough to build it. This lock can be adapted for use on any of the cupboards, chests, or coffers in this book.
Concept of the Medieval Lock
Medieval locks of the type described in this chapter were built differently than their modern counterparts. Today’s locks are set on the inside of a piece of furniture (that is, on the inner face of a drawer or chest), and the exterior keyhole is covered with a decorative lock plate, or escutcheon. The medieval lock was built directly on the back of the escutcheon plate. A small section of wood was chiseled away from the chest’s face, creating a hollow into which the locking mechanism could be recessed. The completed lock and escutcheon were mounted to the front of the chest with nails. To prevent the escutcheon and its accompanying lock from simply being pried from the chest’s face, locks were often mounted with clinch nails, which were longer than the thickness of the board into which they were driven. The excess nail protruding through the chest’s inner face could be bent over, or clinched, on the inside, making the lock far more difficult to remove.
Materials
Most of the lockset, except the spring, lock bar, and key, can be constructed from steel flat stock that is 1⁄16 inch thick. Shape the spring from a piece of 1⁄32-inch-thick spring steel. Using an old hacksaw blade to make the spring seems to work adequately in modern reproductions of medieval locks. Cut the lock bar from a ¼-inch-thick piece of steel. The key is put together from lengths of 3⁄16-inch round stock and a piece of 1⁄8-inch-thick flat stock.
Lock Plate and Hasp
The drawing of the exterior view of the lock shows the location of the keyhole and the opening through which the hasp staple passes. A typical hasp and hasp staple are shown in the drawings. Specific instructions for constructing hasps and lock plates or escutcheons appear in those projects requiring locksets. There are seven rivets on the escutcheon’s face, each bearing a letter or letter-and-number designation in the drawing. The particular functions of these mounting points for the locking mechanism will become clear as you build the lock.
Mechanism Overview
The interior view drawing shows the lockset as it appears when completed and ready to set in place. The jagged bar, shown here as a hatched area and marked A, is the lock bar, the piece that actually locks the hasp into place. The looped piece marked B, fitted around the bar, is the spring that prevents the lock bar from simply falling open if the chest is tilted or jiggled. The rather fish-shaped plate marked C is no more than the framework that holds two simple gates (known to the medieval locksmith as wards), around which the key must pass on its way to the jagged bar, and a small tubular collar that holds the key’s tip in place. There are no moving parts hidden inside framework C. The small plate marked D is a third ward around which the key passes.
Key
The key, as shown in the drawing, is designed to fit through the series of three wards. Locks with different-shaped wards would require keys with different configurations. How the key passes around the wards is shown in the drawings. To personalize a lock, alter the size and shape of the key and the wards through which it must pass on its way to moving the lock bar. Some medieval keys had amazingly complex wards, but the actual locking mechanism was just as simple as the one shown here.
Lock Operation
Lock drawings 1, 2, 3, and 4 reveal the key as it opens the lock. Refer to these drawings before and during the construction of the lock to completely understand its operation. In drawing 1, the key is inserted through the keyhole and the collar steadies it. Th
e removal of both the spring and the staple end of the hasp from drawings 3 and 4 clearly delineates the key in operation. In drawing 3, the key pushes against the lock bar, moving it out of the hasp staple. The key continues its journey past the lock bar in drawing 4; after its 360-degree rotation, it can be removed from the lock. To relock the chest, simply reinsert the key and turn it in the opposite direction.
Lock Plate Construction
The individual chapters provide lock plate dimensions and design. Be sure that the keyhole and hasp staple hole are arranged so that they conform to the dimensions of the particular lockset. Alternatively, adapt the locking mechanism to the configuration of the holes in the particular lock plate of the piece of furniture you are building.
Lock Bar Construction
To ensure your chest’s security, cut the lock bar from heavy, ¼-inch-thick stock to the dimensions indicated in the lock bar drawing. The thickness of the metal requires the use of a band saw with a metal cutting blade. File any burrs from the edges of the lock bar.
Next, cut two lock bar supports from the same ¼-inch metal. The lock bar must pass easily through the slots in the supports. To shape the rivets on the ends of the lock bar supports, use metal files. Begin with a fairly coarse file and work down to a fine-toothed file to smooth your rivet enough to pass easily through a hole in the lock plate. These rivets are square rather than round, which prevents them from turning once they are riveted to the lock plate. Be sure the shoulder at the rivet’s base is square and flat. The rivet must pull tightly against the lock plate so that the lock bar supports will remain firmly in place.
Spring
Now, using a band saw with a metal cutting blade, cut a 43⁄8-inch length of 1⁄32-inch-thick spring steel to the configuration shown in the drawing of the spring before bending. Spring steel is very hard; work slowly to avoid breaking the saw blade or spring. Note: The original lock-spring shown in the drawing is drilled for a single rivet, which may loosen over time. Drilling an additional hole for a second rivet will ensure that the spring remains in place.
Heat 1½ inches at the end of the spring in which you have drilled the mounting hole or holes until the metal glows red. At a point about ¾ inch from the end of the spring, twist the spring a quarter turn with a pair of pliers. This fashions the ear that will attach the spring to the lock plate. Be sure the ear lies as close as possible to the edge of the spring with the notch cut out of it.
Next, heat and bend the small hook near the spring’s opposite end, according to the spring drawing. Because you bent the metal a quarter turn before shaping it into a hook, you will not have to curve the metal laterally. When the spring is finished, this hook fits over the lock bar. Finally, heat an area of the spring about 1 inch on either side of the large offset, and bend the large loop as shown in the interior view drawing. A second, very small loop in the narrower end of the spring allows the spring to hook over the lock bar’s top and exert a slight downward pressure on it. At this point, all the tensile strength (the springiness) will have left the spring. To restore it, heat the entire spring until it glows, and then quench it in a pan of water.
Making the Key
To ensure the smooth operation of the lock, make the key before the locking mechanism is attached to the lock plate. The shaft of the key is a 3-inch length of 3⁄16-inch round stock. Cut the head, or teeth, of the key from a piece of 1⁄8-inch-thick flat stock. When you have cut the teeth, weld them to the shaft at the location shown in the key drawing. The handle of the key can be as elaborate or simple as you like. Our handle is a simple ring bent from a heated length of 3⁄16-inch round stock and welded to the shaft.
Ward Frame Construction
Cut the ward frame, marked C on the interior view drawing, from 1⁄16-inch thick flat stock. Heat it and bend it to shape as shown in the drawings of the ward frame. For instructions on heating and bending metal, see page 9. Drill a 1⁄8-inch hole in each of the ears to facilitate the attachment of the ward frame to the lock plate.
Next, cut a ¼-inch length of thin-walled steel tubing, and weld it to the center of the interior face of the ward frame. The location of this cylinder can be clearly seen in the ward frame interior and top views. This cylinder holds the key in its proper position when the lock is being opened or closed; when the ward frame is riveted to the lock plate, the cylinder must be directly behind the circular open- ing at the top of the keyhole.
Cut two rectangular ward blocks from 1⁄16-inch flat stock as shown in the interior and top views. Be sure that the ward blocks pass easily through the notches in the key. Shaping the rivets on the ends of the blocks resembles working on the lock bar supports, but these rivets must be round rather than square. Begin with a fairly coarse file and work down to a fine-toothed file to give your rivet a smooth surface that will pass easily through a hole in the lock plate. Again, be certain the shoulders at the base of the rivets are square and flat to ensure that the ward blocks do not turn once they are riveted in place. The rivets can be welded to the ward frame once they have been peened in place on the lock plate.
Drill a 1⁄16-inch mounting hole for the ward block in the ward frame to the left of the key cylinder, as shown on the interior view of the ward frame. To ascertain this hole’s exact position, place the end of the key in the cylinder and position the ward block in the proper notch in the key. Place the ward frame in position on the interior surface of the lock plate and replace the key in the cylinder. Position the ward frame so that the key can be removed and reinserted through the keyhole without difficulty. Clamp the ward frame in place on the lock plate, and determine the position of the ward block that mounts on the face of the lock plate. The key must be in the lock for this phase of the operation, or the ward block may not align with the key. Now remove the key and ward frame, and drill and mount the second ward block. This rivet is marked C on the exterior view drawing.
Reposition the ward frame on the lock plate and reinsert the key. Mark the locations of the ward block’s mounting holes on the lock plate. Remove the ward frame and drill the holes in the lock plate. These will hold rivets A1 and A2 on the exterior view drawing. Remount the ward frame and position it with two small rivets. Again, make sure the key fits into the ward frame and passes both of the ward blocks.
The final ward, shown as D on the interior view drawing of the lockset and detailed in the third ward drawing, passes through the small slit in the center of the key. Bend this ward from a heated piece of 1⁄16-inch-thick flat stock. Be sure that the key can pass around it when it is fitted against the lock plate. Drill a hole in the ward’s tail and a corresponding hole through the lock plate’s face (B on the exterior view drawing), and rivet them together.
Attaching the Lock Bar and Spring to the Lock Plate
To guarantee that the lock bar lines up with the key, first place the key in the lock. Then position the lock bar on the lock plate so that the end falls across the hasp staple hole as shown in the interior view drawing. Set the lock bar supports in place on the lock bar so that the rivets are beneath the lock bar. There must be enough space between the lock bar supports to allow the spring to set between the small ear on the upper left corner of the lock bar and the lock bar support on the right (see the interior view drawing). The lock bar must also be positioned so that the key will move it from left to right as it is locked and unlocked. The key’s only contact on the lock bar should be with the downward-pointing teeth; it should not touch the bottom of the bar itself.
Mark the positions of the rivets on the lock bar supports, and drill 1⁄8-inch holes in the lock plate. With a small file, rub the holes square, then insert the rivets and peen them over. Note: If you do not have jeweler’s files, file the rivets round, mount them in round holes, and weld them into place to ensure that they do not shift. Place one of the lock bar supports in its proper hole, and peen over the rivet on the lock plate’s face. Insert the lock bar and the second lock bar support into place, and peen over the second rivet. These holes correspond
with rivets D1 and D2 on the exterior view drawing. The lock bar should now move freely back and forth in front of the hasp staple hole.
Set the spring in position on top of the lock bar. Clamp the ear on the end of the spring to the lock plate, and open the lock with the key. The key should lift the spring out of the way so that the lock bar can pass beneath it. If the ear on top of the lock bar is too long to pass under the spring, file it down slightly. Be sure the key does not require too much effort to turn. When the lock operates satisfactorily, mark and drill a hole or holes to accept the rivet or rivets that will hold the spring in place. If you use only one rivet, position the spring so that it exerts slight pressure on the lock bar before you place the rivet. If you use two rivets, drill and install one rivet near the spring’s long end, and then, using the first rivet as a fulcrum, apply slight pressure on the lock bar and mark and drill a hole for the second rivet.
Now the lock can be locked and unlocked with relative ease. After hollowing out an appropriately wide and deep trough on the face of the chest, permanently mount the lock with clinch nails.
Lock Set without a Hasp
Locks such as those on the Cathedral Cabon and Reading Desk do not have hasps. Instead, the lock bar simply slides behind the stile nearest the lockset, making it impossible to open the door. We recommend attaching a small metal plate to the back of the stile to prevent the lock bar from tearing away the wood on the edge of the stile.