Furniture and Furnishing

Furniture and Furnishings 3(1+2)

Lesson 05: Furniture Construction

The Different Types of Common Joints Are

1. Butt
2. Dovetails
3. Housed
4. Lap or Halved
5. Miter
6. Rebate
7. Tenon and mortise
8. Tongue and groove
9. Dado
10. Dowel

It is important to note that for joining wood always use sharp tools. Square all ends edges and faces before making a joint. Mark carefully and always cut on the waste side of the lines.

Butt joints are the easiest of all to make. Wood is butted face to edge or end to edge and nailed, screwed or dowelled together.

End to edge joints:
can be joined with corrugated fasteners.Strength can be added by gleuing the joining faces. These joints are not recommended for hardwood unless pilot holes and screws or dowels are used to hold them together.

Dovetail Joints:
Dovetail joints are very strong and neat joints used primarily to make drawers and boxes. It needs a lot of practice to make a good dovetail joint.

Marking for dovetail joints

1. Square the ends of the wood to be dovetailed.
2. Set the sliding bevel to a suitable pitch of between 1 in 6 for heavy work and 1 in 8 for smaller and more detailed work. Avoid sharp angles as the points of tails break easily.
3. Scribe the tails on the end and face of the wood and mark the “waste” pieces.
4. Clamp the wood in a vice and cut on the waste side with a tenon saw.
5. Lay the two pieces over each other and transfer the markings through the cuts with a tenon saw.
6. Remove the waste between tails and pins with a chisel.

Lapped dovetails are mostly used for drawer fronts as they give a very neat, strong joint with only one side showing end wood. Marking is the same as for open dovetails but the cutting out between the pins needs a fair amount of chiseling. Special dovetailing bits are available for routers, which are ideal for this job.

Housed Joints:
Housed joints are mostly used for shelves. The stopped house joint hides the actual joining. Use skew nails or screws to fasten the boards together.

Lap or Halved Joints:
Halved joints or lap joints are mostly used to assemble light frames which are going to be covered with hardboard or plywood. Half the thickness of each piece of wood to be joined is cut away with a tenon saw and the joint is glued and screwed or nailed. Halved lap joints are also used to join long lengths of timber.

Miter Joints
Miter joints are always cut to 45° in a miter box so that they will form a 90° corner when joined. As no end wood is ever seen, these are very neat joints but they are weak. Normally used for picture frames where they are nailed with panel pins. When used for other purposes they must be strengthened with glue blocks,angle braces or loose tongues. Miter joints should always be glued.
When nailing a miter joint always start the nail with one part of the miter above the other. The nails will pull the miter into square.

Rebate joints
Rebate joints are suitable for joining top and bottom ends of furniture. Stopped rebate joints hide the joint. Glue and skew nail are also used to two piece of wood joint together.

Stopped rebate joint

Tenon and Mortise Joints
Tenon and mortise joints are very strong joints mostly used in furniture making and for heavy doors and gates. They are not easy joints to make. The secret in making a good tenon joint lies in careful and accurate marking. The tenon’s width should not be less than a third of the thickness of the wood especially if wood of the same thickness is joined. The shoulders may be of any width and may also be offset when the mortise is made in rebated wood. Make the mortise before rebating the wood. If the top of the mortised wood is to be in line with the edge of the tenoned wood a haunched tenon can be made with the haunch cut back to be in line with the shoulders.

Tongue and Groove Joints
Loose tongued joints are used to join planks edge to edge to form a larger board like a table top in which case they are always glued only.
Bare faced tongue and groove or Loose tongue and groove joints can be used to join chair rails to chair legs.

Dado Joint
A dado is a groove cut across the grain of a piece of wood. A dado joint is formed by cutting a dado in one piece of wood the exact size as the square-cut edge of another piece. The square-cut edge of the second piece is then inserted into the groove of the first piece to form a tight, secure joint. This type of joint is also usually glued. Dado joints are commonly used to join wood at right angles, as in bookcase shelves. Sometimes the dado is hidden because the groove is not cut all the way across the board to the front of the bookcase. This kind of dado joint is called a blind dado.

Dowel Joint
Dowel joints are basically substitutes for mortise and tenon joints. Many modern pieces, particularly chairs, are constructed using dowel joints. A dowel joint is made by fitting a butt joint and then drilling corresponding holes in the two pieces of wood to be joined and inserting the dowel pin or pins before joining the pieces. Glue is used in this type of joint, and the dowel pins serve as round tenons, holding the two pieces together. Although dowel antique furniture joints are commonly used and are easier to make than a mortise and tenon joint, they usually aren't as strong.

Drawers and doors: If the piece in question has drawers, these are frequently a good indication of the general level of workmanship. The insides of the drawers on good-quality furniture are smoothly finished and treated with a coat of shellac or varnish. The top edges on the back and sides are rounded for smoother operation. Drawer pulls also offer some indication of quality and thus affects the cost of construction.
Cabinets and breakfronts often have doors made with panes of glass set into a wood frame. On high-quality furniture, the door might be composed of a rather intricate latticework of wood with each piece of glass set in place as an individual section. This process, called muntin or mullion, is expensive, especially if the glass sections are curved or bent. Less expensive copies of such design often use one panel of glass with a wooden lattice or fret superimposed on it.

Finishes: Manufacturers of fine-quality furniture take great pride in selecting materials. The surface of the wood is treated and polished to develop a beautiful color and patina-a mellowness or “glow” that comes from much rubbing and polishing. The grain pattern is carefully placed to enhance the design of the piece; sometimes panels are formed of matched sections to form an intricate design.

Decoration: Those furniture styles that require some form of embellishment, such as inlay or stenciling, are naturally more expensive to produce than the plain, simple forms. Fine carving and inlay work are expensive modes of decoration and they are rarely found in low-cost quality furniture. Cheap imitations that stimulate such skillful craftsmanship are usually crude and unattractive.

Materials: Wood always has been and still is the favored materials for furniture construction. However, metal, glass, plastic, and various fibers/fabric ( upholstered furniture ) are also used, particularly for furniture in the modern style. Frequently, interesting effects are achieved by the use of these various materials in combinations.