Basics of Woodworking

Finishing

The workmanship and materials determine the value and usefulness of your project, but its final appearance will depend on the finish. This last step in your work deserves a great deal of planning and care so that the effort put into a project is not ruined by bad finishing.

A finish is applied to the surface of the wood to seal and protect it against moisture and light, and to enhance the surface or cover blemishes.

Less expensive woods and sheet materials are often finished with opaque finishes such as emulsion or gloss paint which cover blemishes and make the surface uniform and smooth. More expensive woods are finished with transparent finishes like polyurethane var­nishes and oil wood stains which accent the beautiful grain patterns. The first step in finishing the wood is to prepare the surface by sanding it until it is smooth and even.

Sanding

Glasspaper is the most important finishing tool. Without it, no job is really complete. It is used to remove all the scratches and nicks caused while you are working the wood, leaving the surface smooth and even. The smoothness of the finish will depend on the fineness of the glasspaper. Glasspaper or sandpaper is coated with an abrasive which cuts the surface of the wood and smooths out all the rough spots. It is sold in many grades from very rough to extremely fine, and with a variety of abrasives. The higher the grit number, the finer the glasspaper is.

Glasspaper can be used across the grain for rough work, but the result will be a scratchy surface. For finished work, it is essential to sand with the grain. Begin with fairly coarse paper and then use progressively finer grades until you have achieved the finish you want.

It is easier to sand if you wrap a convenient-sized piece of sandpaper around a small rectangular wooden block or purpose-made cork sanding block. This allows you to apply even pressure when you are sanding and it is not so rough on your hands. For sanding in rounded corners, wrap a small piece of sandpaper around a short length of dowel.

Hand sanding can be a tedious and time-consuming job, especially with hardwoods. Power sanders are useful for major sanding, but the final touches should be done by hand. It is very important that the final sanding is along the grain, avoiding circular or cross motions, otherwise the surface will he scratched and will have to be sanded again to get it smooth.

Immediately after sanding brush or wipe off the dust with a soft cloth or brush. For an even smoother surface, wipe it with a slightly damp rag or sponge to raise the grain of the wood. When the surface is once again dry, sand it once more with a very fine sandpaper.
The wood is now ready for an application of the protective finish.

TOP: Always sand with the grain and a sanding block for best results.
CENTRE: to sand grooves wrap sandpaper around a dowel.

Fillers and stoppers

If a board has cracks, splits or holes which need to be filled, or if you want to sink nails and screws and fill the holes so the surface is smooth, this can be done with plastic wood, putty, or polvfilla, depending on the kind of materials you are filling. Plastic wood compounds are available in a variety of wood colours and can therefore be used to fill flaws in many different woods. If the colour of the filler does not match the wood exactly, mix some of the filler with fine sawdust of the wood or add a few drops of wood stain. Apply the filler to the surface with a putty knife or spatula, allow to dry and then sand smooth.

There are other types of fillers used by professional woodworkers to fill the overall grain of the wood so that it is extremely smooth and will take a finish evenly. These come in paste or liquid form. Paste fillers are used for open-grained woods like oak, ash, walnut and mahogany, and liquid fillers for close-grain species like pine, maple and Douglas fir. For the home handyman, it is sufficient to sand a surface well before applying a finish.

ABOVE: Fill any cracks with tiller and them sand smooth when it has dried

Painting

Painting wood and sheet materials is a good way of hiding blemishes, and adding colour and creating accents in a project. Once the surface is even and smoothed, paint will cover any imperfections.
It is a good idea to apply a primer coat to the surface, either an undercoat specially made for the purpose or a sealer like a polyurethane varnish.

This will provide a smooth base for the paint and reduce the amount of paint which sinks into the surface, making the finish more even. Allow the sealer enough time to dry thoroughly and sand it lightly before applying the first coat of paint. When painting sheet materials, at least two coats will be needed in addition to the undercoat to get a really even finish. Smooth the surface of chipboard and plywood by wiping it with a very watered-down solution of polyfilla and fill in the grain. Allow it to dry and sand it smooth.

Emulsion paints dry very quickly and are odour-free and therefore more pleasant to work with than gloss paints. An emulsion surface can he touched up and will dry a uniform colour, cutting out the need to repaint the whole surface. As emulsion paints are water-based, brushes clean easily with soap and water. But as emulsion paints are fairly dull in finish and are not entirely waterproof, they are suitable only for indoor work.

Gloss paint provides a harder, more durable surface. It is, however, more difficult to apply evenly. It is essential to begin with a smooth surface and to apply an even undercoat before painting with gloss. Paint continuously in one direction going back over the areas covered to smooth out any drips or imperfections. Allow the paint enough time to dry if more than one coat is applied, sanding lightly between coats.
The advantage of finishing items in gloss paint is that you can wash them later with soap and water. Even though sometimes more attractive, emulsioned work is not as easy to clean.

Staining

A stain adds warm wood tones or bright colours to the wood without hiding the grain. It is used to protect the wood without hiding it. Inexpensive woods can be stained to look like a wide range of more exotic types from rosewood to walnut and teak. Stains are usually either oil or water based.

Oil based stains give a more even finish for wood tones, but test the colour on a scrap of wood before starting, to decide it you like it and also to determine how many coat" of stain are necessary. Before staining, wipe the surface with a damp rag to raise the grain, alloy, it to dry and then sand it smooth with very fine paper. In this way the surface will accept the stain evenly, without raising the grain.

Apply the stain freely and quickly with a brush or cloth working with the grain. Avoid overlapping the strokes or the stain will he darker in some places. Apply at least two coats of stain for a rich finish, then apply a coat of clear varnish to bring out the richness of the grain.

Stains can also be used on sheet material. Ii wood stains well in a range of wood tones like teak and oak, but choose the best side of the sheet to use as the face side. Chipboard too looks quite elegant in a variety of wood colours which bring out the texture of the surface.

.LEFT, FROM TOP RIGIIT: These Dylon wood stains shine the aide range of u od finishes to choose from: pine (matt), Carmesine, sauna blue, pine (gl&5s), medium oak, red cedar, rosewood.

Varnish

The most commonly used varnishes are polyurethane varnishes, available clear in matt, satin or gloss finishes and in a variety of colours, either wood tones or bright decorator colours. Polyurethane varnishes are extremely durable and resistant to water, alcohol, and other solvents.

They can be applied over wood stains or directly on to well-sanded wood for a warm, natural look. Brush on the varnish liberally with the grain, thinning down the first coat slightly with white spirit.

Allow 24 hours for each coat to dry. Sand lightly with very fine glass paper between coats and wipe down with a damp rag. Apply at least two coats for a lustrous finish.

For a matt finish, only the final varnish coat should be matt: the first coat should be gloss. After the final coat is rubbed down with fine wire wool, rub in a coat of wax for a really luxurious surface.

Polyurethane varnishes in wood tones eliminate the need for first staining and then varnishing the wood. Both operations are combined in one. Several decorator colours including blue, green and red are also available and look especially attractive on pine chipboard and plywood.

Varnishing is not a complicated task. but there is a correct way of doing it. By following this method, you should be guaranteed a smooth and even finish on every job. First apply line garnish in strip; (1) along the grain of the timber. Then brush across the grain (2) to fill in the areas and finally (3) brush lightly over file Whole surface along the grain to smooth over the varnish. Repeat this procedure for adjacent and remaining areas.

Brushes

Each type of finish uses a different solvent and it is therefore best to use a brush for only one type of finish. Mark the brush handles to indicate whether they are to he used for gloss paint, varnish, or emulsion paints.

Before using a brush, it is wise to clean it by shaking oft any dust and washing it in turpentine or white spirit. Dry it off thoroughly before using.
the best brushes are made of natural bristle but they are very expensive. Nylon-bristle brushes are suitable for most jobs and cost a lot less. It is always a good idea to buy the best quality brush you can afford and to take very good care of it, rather than buy cheap brushes which will not last as long and do not give as smooth a finish.

Clean brushes thoroughly after use in the appropriate solvent and then wash in warm soapy water. Smooth the bristles in place and allow the brush to dry thoroughly. Keep the clean brushes wrapped in paper and stored flat.

Wax polishing

To achieve a really soft and satiny finish, the wood can be rubbed with wax. Both paste and liquid waxes are available and wood workers mix their own waxes for each job. Several thin coats of wax well rubbed in with a soft cloth are better than one thick coat, as this allows the wax to soak into the wood. Wax can he applied on to the bare well-sanded wood or over stains or varnishes for a really luxurious finish. Buff each coat of wax vigorously with a soft cloth to bring out the full beauty of the wood.

Hand-rubbed finishes

if you have made a fine piece of furniture or used an especially beautiful piece of hardwood, it is worth the time and work to hand rub the finish. Two methods are useful for the home handyman. The surface of the wood can be rubbed with a very fine grade wire wool until it is glass smooth and then waxed, or it can be rubbed with a paste made of water and pumice powder, available from hardware shops, on a felt pad. Either method will smooth and polish the wood beautifully.

If the wood has been varnished, rubbing with the pumice compound will dull the surface and take away any lacquered look. The wood can then be waxed finally to give it an extra shine. There are other, professional, hand-rubbing methods such as French polishing which are complex and require specialist materials.

Oil finishing

An oil finish is an extremely simple and durable finish which is moderately resistant to heat and water and is therefore often used for dining tables. It suits several kinds of hardwood such as maple and teak.

Use ready-made teak oil or mix equal parts of linseed oil and turpentine and rub it into the surface of the wood. Teak oil is better, as it leaves no watermarks. Repeat the process once the oil has soaked in, wiping the excess off each time with a rag, to build up several coats. The finish penetrates into the wood and enhances the grain.

The great advantage of an oil finish is that a portion of the surface can he reworked without refinishing the whole, as the oil blends readily into the wood. Renew the oil finish from time to time, depending on the kind of use the wood is getting. A teak draining board should be oiled every two months, and a maple dining table even three months.

The key to a good oil or wax finish is several applications of thin coats as oppossed too one thick coat. Apply oil or wax finishes with a soft, clean cloth and move your hand in a firm circular lotion. There is a wide range of waxes and oils you call use on wood; if in doubt, consult a timber merchant or furniture shore. For legs and other rregular shapes. rub in an up and down movement, again with a soft cloth, making sure you cover the area completely.