by Daniel Diehl
Materials
This window frame is made entirely of oak. Obtaining 5½-by-7-inch oak timbers may prove challenging. If necessary, glue up the structural members of the window frame as discussed on page 2. Other woods may be used for this project, but do not use pressure-treated or weatherproofed construction lumber, which will split and warp in a short period of time.
Framing
The first step in building this window is to lay out and construct the frame. Note that the sill fits between the side beams, and the lintel fits across the top of the side beams. Keeping this arrangement in mind, proceed as follows.
Cut the tenons on the top ends of the side beams and both ends of the sill plate, as shown in the drawings. Then arrange the side beams and lintel on a level floor in proper relation to each other, at 90-degree angles. Mark the locations where the tenons should be mortised into the lintel. Remove the lintel and, following the same procedure, place the sill plate in position against the side beams, again at 90-degree angles. Mark the locations where the tenons should be mortised into the side beams. Now cut the mortises into the lintel and side beams, maintaining a snug fit. The process can be simplified by using a drill to remove some of the excess wood from the mortise. For the finish work, use a mallet and chisel.
Assemble the four pieces of the frame, being certain that the fit is snug, level, and square. Working on a piece of furniture as large as this window requires some practice. If your frame is slightly out of square, small shims can be inserted into the mortise and tenon joints to compensate for a slight twist. Do not, however, rely on shimming and wedging to take the place of careful craftsmanship. The structure is strongest when the parts fit together well.
Locating the Mullions
With the assembled frame laid out on the work floor, mark the locations of the four mullions. Note in the drawings that the mullions are against the inside face of the window frame, not in the center of the frame, and that the two window openings on the right side of the frame are slightly narrower than the three on the left. Trace the outline of each mullion on the top surface of the sill plate and the bottom side of the lintel. For ease in marking the mullion outlines, make a cardboard template based on the mullion detail drawing. The template does not need to have the moldings indicated; the general outline is sufficient.
Next, mark the location of the mortise inside the outline of each mullion. Also mark the location of the molded edges on the side rails and lintel. Mark the point where the sill plate intersects with the side rail. This locates the bottom edge of the side rail molding. The molding is broken by a series of returns as it crosses the lintel. There is a return at each mullion, as well as at the outside corners of the window. The returns at the outside corners of the window are square (a 90-degree angle), but those at the mullions are wedge shaped. This can be seen in detail on the window frame construction drawing. These wedge-shaped returns are important because portions of the molded design on the mullions do not line up with the molded design on the frame, and the wedge masks this discrepancy.
Mullions
Leaving the frame temporarily, move on to the mullion bars. Even before the decorative molding is cut, the blank mullion is closer to diamond shaped than it is square. For this reason, start with a rectangular blank the size of the greatest dimensions of the mullion, 4½ by 35⁄8 inches. From this blank, work the decorative molded edges first, and later cut the wedgeshaped back side of the mullions.
These moldings are complicated and must be executed slowly and with care. Portions of them can be cut with a router or handheld grinder, but because of the extreme convolutions, they are best executed either with an old-fashioned molding plane or on a professional-quality molding cutter. After you have cut all the moldings and backs onto the mullions, cut a tenon into the top end of each mullion (the end that will be fitted into the lintel).
Cutting Rabbets
Now disassemble the frame. In the mullions, lintel, and side beams, cut the rabbets into which the trefoil decorations are seated. Note in the trefoil detail drawing that the rabbets run slightly deeper into the side rails than they do in the lintel. The rabbets do not pass through the mullions; each mullion has separate rabbets for the trefoils on the left and right. The shaded areas in the section A drawing show how these rabbets line up across the face of the window. For ease of cutting, the rabbet in the lintel can be run the entire width of the window opening. It does not have to stop at each mullion.
Cutting Mortises
Cut the mortises in both sill plate and lintel at the locations you marked previously. The rabbets and mortises will overlap on the lintel, but this is of no consequence because the mortises are considerably deeper than the rabbets. Fit the mullions into the mortises in the lintel. Check that the wedgeshaped returns line up with the acornshaped bead on the front edge of the mullion, and make any necessary adjustments. Marking which mullions fit best into which mortises may save you time in relocating them later. It is unlikely that they will be interchangeable.
Edge Molding
Now cut the moldings along the inside edges of the side beams and lintel. These relatively simple moldings can be cut with either a router or molding plane. At least two cuts must be made: one on the outer surface of the frame, and the other on the inner face of the window opening. Cut the moldings on the side beams first, because they are a straight, uninterrupted run from the top of the sill plate to the end of the beam. Cut the point where the molding stops at the top of the sill square with small chisels or carving knives.
Next, cut the molding into the lintel using the same process. Pay careful attention to the returns, all of which will have to be finish-carved with chisels and carving knives. To execute the final carving around the wedge-shaped returns, insert the mullions into the lintel to ensure the best alignment of the returns with the front of the mullions.
Fitting the Mullions
Now reassemble the side beams and sill plate, making certain that they are in square. Align the lintel, with the mullions in place, on top of the side rails and rest it on the side rail tenons. The bottom ends of the mullions should be resting on top of the sill plate. Realign the entire structure to ensure that all pieces are in square. Position each mullion in line with the proper mortise hole in the sill plate, and mark the exact length of each mullion bar. Then remove the mullions from the lintel and cut the bottom tenons. With the exception of the trefoils, the entire window frame should now fit together snugly with the tap of a mallet.
Trefoils
Cut to length the boards from which the trefoils will be cut, so that they fit between the mullions. Reassemble and square the entire frame with the trefoil blanks in their proper places. Then draw a line around the top and side edges of the trefoils, and mark each trefoil so that it can be returned to the same window opening after it has been carved. Remove the lintel and lift the trefoils from the window frame.
Enlarge the trefoil detail drawing on a copier until it fits properly onto the trefoil board. Using a sharp knife, cut around the decorative outside edge and the inside piercing of the trefoil design. Trace the pattern onto the trefoil board and use a coping saw or reciprocal saw (saber saw) to cut out the inside and outside designs. Finish-sand all the edges.
With gouges, a handheld grinder, or router, cut back the inner and outer faces of the design as shown in the drawings. These edges are slightly concave and are worked on both the inside and outside surfaces of the window. Finally, execute the low relief carvings, shown as shaded areas in the drawings.
Feet
If the window frame will be a freestanding piece, you need to construct feet. The feet should be the same dimensions as the side beams, 5½ by 7 inches. To support the height of the window frame, they have to be 38 inches long. Thus they will extend beyond the front and rear faces of the window a distance of 16 inches. The exposed ends of the feet can be given decorative treatment, such as the lion’s paws on the Curule Chair, or left simple, like the feet on the Gothic Cradle. The top
edges of the feet can be chamfered slightly to relieve the harsh edges.
The feet need to have braces running from near the outer edge of each foot to approximately 16 inches onto the side rails. Cut the bottom 5 inches of each side rail into a tenon 3 inches square. Cut a corresponding mortise in the center of the foot. The braces do not need to be cut into a decorative shape. Attach them to the feet and legs as described for the leg braces on the Gothic Cradle.
Final Assembly
If you are building the window frame without feet, it will have to be assembled lying flat. Repeat the steps for assembly, be sure the frame is square, and clamp it together so that it does not shift during pegging. Use bar clamps or strap clamps, or tie hemp ropes (do not use nylon ropes, which will stretch) around the frame and tighten them by placing a short stick between the ropes and twisting the stick until the ropes tighten. Pad the points where the clamps or ropes come in contact with the frame to avoid scarring the wood.
Doweling
When the window has been squared and clamped, drill pilot holes for the dowels and drive them into the holes. Tapering the dowels will make them easier to seat. The dowels used for the main framing members are ¾ inch in diameter, and those used to hold the mullions in place are only ½ inch. When the dowels are in place, remove the clamps and finish the ends of the dowels flush with the surface of the window.
Attaching the Feet
The feet can be attached before or after the window frame has been assembled. If they are attached to the side beams before assembly, the window must be assembled in a standing position. In this case, once the feet have been attached to the side beams, insert the sill plate into the side beams, and then set the mullions into the sill plate. Set the trefoils in place between the mullions and place the lintel on top. Then square, clamp together, and drill and dowel the entire frame. If the window is assembled in a standing position, the drilling and doweling procedure will be slightly more difficult than if the piece is lying flat.
PROJECT 35
Fifteenth-Century Interior Door
Interior Door replica; original, English, fifteenth century. Oak, 71¼ x 30 x 2 inches. Collection of Mount Grace Priory, Northallerton, North Yorkshire, England. Photo by D. Tyler Huff.
The door has been a primary symbol of security since the concepts of privacy and personal property first developed. In the Middle Ages, hermetic monks, sometimes known as anchorites, used doors to protect not property, but privacy. The Carthusian monks at Mount Grace Priory, Yorkshire County, England, were no exception in the quest for solitude despite their communal living arrangement.
The fifteenth century saw tremendous growth in many of the richly endowed monastic communities, including the one at Mount Grace. Here the community of monks lived in a complex of individual cells that were as comfortably appointed as any merchant-class house. Each cell was a fourroom house complete with an attached walled garden and piped-in water. These pleasant surroundings, however, did not lessen the physical severity and social deprivation to which the brothers subjected themselves. Their isolation was nearly complete. Even their meals were passed through a slot near the entrance door of the cell. To ensure such privacy, stout doors were needed. This pegged oak door, from reconstructed cell number eight at Mount Grace, is a masterful example of the carpenter’s art. Constructed completely of oak, without metal fasteners or hinges, this heavy door swings as easily as any modern door.
Construction Notes
An interesting feature of this door is that it is held together with wooden nails. They are not simply pegs, as are most wood-to-wood fasteners, but fully developed nails, with a head on one end, carved from oak. The door is made even more interesting by having no visible hinges. The main carrying timber (the plank on the hinge end of the door) is set with two large pins, one each at the top and bottom. These pins in turn are set into sockets in the door lintel and the sill plate, which in medieval buildings usually sat above the floorboards. Though having the sill plate above the floor may have been a nuisance when someone moved from room to room, it greatly facilitated the construction of post-and-beam walls.
Because there is no locking mechanism on this door, it may not technically have an interior and an exterior face; however, judging from its location at Mount Grace Priory, the flat side of the door should be considered the outer side and the face with the cross braces the inside. Construction of this piece may appear quite simple, but brace yourself for a real challenge.
Materials
The door is made entirely of white or red oak, although it could conceivably be made of a different wood. However, the wooden nails must be made of white oak, because it is much harder than most other woods. The hinge pins, or swing pins, should be made of maple or birch, which are more resistant to wear than oak.
Nails
Because the entire structure is held together with wooden nails, they should be the first items made. The overall length of the finished nails is 3 inches, but they will be easier to handle while they are being carved if they are worked, one at a time, from 1-foot lengths of stock. You should be able to carve about three nails from a 1-foot length of oak stock.
Mark the location of a nail head at one end of a length of ½-inch-square stock. The nail head should be the full dimension of the stock and ½ inch in height, and the body of the nail 3/8 inch in diameter. With a jeweler’s saw, fine-tooth coping saw, or very sharp carving knife, score a line around the bottom of the nail head. On the flat sides of the stock, the scoring should be cut to a depth of only 1/16 inch. Because the body of the nail is round and the head square, the cut needs to be deeper at the corners of the stock.
Now carefully shape the body of the nail. When you are carving toward the head of the nail, be careful not to chip away the corners of the head. At some point in the carving process, you will need to saw the nail free from the length of stock. When the nail is nearly round, finish shaping it with sandpaper. You need good, sharp, clean corners where the body of the nail joins the head so that the nail will seat tightly against the face of the door. When the body of the nail is complete, sand or carve a bevel around the head and another bevel around the bottom of the nail. The bottom bevel will allow the nail to be driven into the pilot holes more easily. You need a total of thirty-four 3-inch-long nails.
Swing Pins
Trim the carrying timber (the thick plank on the hinge side of the door) ½ inch shorter than the height of the door opening. Locate the positions of the swing pins on the top and bottom of the carrying timber. The pins should be ½ inch from the outside edge of the door, as shown in the door mounting drawings, and at the center of the carrying timber’s 2¼-inch thickness. The pins must be at the same locations on the top and bottom of the carrying timber so that the door will operate without binding or twisting.
Drill pilot holes for the swing pins to a depth of 2 inches. The holes must run perfectly straight into the carrying timber or the door will not swing properly. Set the swing pins into the pilot holes with a wooden mallet. The pins will drive more easily if you sand a slight chamfer around the bottom edge. When the swing pins have been seated, 1¼ inches of the pins should stick beyond the face of the door. Sand chamfers onto the exposed ends.
To make the swing pins more stable, they can be cross pinned (fastened to the carrying timber) by inserting a 3/8-inch dowel through the door and swing pin. The dowel should run through the faces of the door, not into its edge.
Door Boards
The combined widths of the boards allow this door to fit in its frame. The widths of the boards in your door may vary depending on the width of your door frame. This door can be widened to 33 or 34 inches without developing any structural problems. The finished width of the door must be 7/8 inch narrower than the interior dimension of the door frame to allow it to swing freely on the swing pins. When the proper widths of the door boards have been established, trim the boards to the same length as the carrying timber.
Cross Braces
The length of
the braces is determined by the width of the door. If your door is wider or narrower than the door in the drawings, adjust the length of the braces accordingly. The braces must be long enough to provide a 1¾-inch tenon on one end and stop ½ inch short of the outside edge of the door on the other. The brace is 1 inch thick, and its width narrows from 4 inches at the point where it meets the carrying timber to 3 inches near the outer edge of the door.
Rough the brace into shape, then cut the tenon. The tenon, as shown in the section A drawing, is flush with the surface of the brace on the side that lies against the door boards. On the opposite side, the tenon is offset by ¼ inch, leaving the tenon ¾ inch thick. The tenon should be offset from the top and bottom edges of the brace by ¼ inch. This slight offset will conceal the edges of the mortise. Next, chamfer the edges of the braces as shown in the end view of the brace drawing.
Cutting the Mortises
Lay the carrying timber and door boards on a level work surface. Then lay the braces on top of the door boards with their tenon ends touching the carrying timber, spacing the braces along the height of the door as shown in the inside face drawing, and at a 90-degree angle to the carrying timber. Mark the locations of the tenons on the carrying timber. Then lay aside the door boards and cross braces.
Cut the mortises into the carrying timber so that the tenons will fit very snugly. A very snug fit requires three or four taps with a wooden mallet to seat the tenons into the mortises. If you have to drive the pieces together, they are too tight and the wood may split from the pressure. The mortises must be cut square into the face of the carrying timber. If they are not square or the tenons are not a good fit, the door may sag. Cut each mortise individually until one of the tenons fits, and then mark them for reassembly, as the pieces may not be interchangeable. Markings should be done with chalk or on masking tape so that they can be easily removed.