Finishing and Ageing Methods
There is a wide range of finishes available and only by experimenting will you find one that suits your needs. However, in spite of the different eftects you can achieve and the slight variations in terms of application, there is a fairly standardnapproach to the finishing process and outlined below are a few general guidelines which should be taken into consideration.
The use of sand paper is often frowned upon as, used incorrectly, it does tend to round over sharp edges and crisp lines which have been painstakingly strived for. This can be avoided, however, by using sanding blocks (see page 29).
It is absolutely imperative that when using carving chisels the maximum effort is made to achieve a fine finish before you even consider applying a wax, polish or stain, but sandpaper is useful for smoothing the overall surface and removing tiny tool marks and scratches which when polished, become exaggerated. When sanding I would rarely use anything coarser than 120 grit and usually finish off with 1200 grit. All traces of dust and loose fibres must then be gently removed with a clean nail brush.
If you wish to stain the carving you must be aware that the stain will be absorbed at different rates as a result of the diverse amounts of exposed end grain. This will obviously present you with an uneven distribution of colour, which is intensified with softwoods or if quantities of stain collect in inaccessible crevices. Although it is a factor which must be taken into consideration, when polished it often appears quite attractive, adding depth and perspective to the carving. I would, therefore, strongly recommend that you consider the suitability the stain for the job and most importantly always try it out on a piece of scrap timber first.
The grain should not be raised as this will only lead to further use of abrasive papers or wire wool. Water-based stains should therefore be avoided, with spirit and oil based stains making better choices. Apply the stains liberally with a brush to ensure that all areas are covered. Then with a cloth remove the surplus and allow the stain to dry.
Whichever polish you decide to use, whether the timber has been pre-stained or not, it is sensible to avoid the thicker polishes. The general rule is that the polish should not appear any thicker than water. If it does, it should be thinned. I find that most shellac-based products, for example button polish, transparent polish and sanding sealer are excellent because of their quick drying characteristics. Ensure that the timber is free from all traces of dust and unwanted marks. Using a good quality brush or polisher’s mop apply the polish sparingly, as it is essential to prevent it from running or collecting in any recesses.
Remember, three thin coats are better than one thick one! Usually after approximately four or five coats, a sufficient sheen has developed which, after drying, can be cut back or de-nibbed using grade 0000 wire wool. Rub the polish very gently until all traces of shine have been removed to form a very smooth matt surface.
On polished wood the amount of light reflected from the surface determines the degree of shine. If you were to examine various objects under a microscope you would find that those formed by closely connected molecules tend to be the most reflective. You will also find that the smoother the object, the more intense the reflection. Timber in its natural form can be compared to a bundle of drinking straws, the holes representing the end grain and the length of the straws forming the long grain. The very nature of polish is that its molecules are more densely packed than those of timber. Therefore when applied to the surface of a piece of wood it enhances the sheen. (Think of a table top or a piano which has been French polished for example.)
However, before the polish is applied, the timber must be carefully prepared to a fine finish as a smooth surface will allow you to achieve a greater quality of sheen. The surface of the timber across long grain is made up of closely knitted tubes which form a series of ridges and valleys. When the polish is applied it coats the entire surface, not only filing the valleys, but also making the ridges higher. It is common practice to cut back the polish using very fine abrasive paper between coats. This helps to reduce the height of the ridges, allowing the valleys to reach the same level which in in turn forms an entirely flat surface and gives a a brighter sheen.
After the polish has been carefully and evenly applied, it should be allowed to cure. Even when using thinner polishes, which in general dry more quickly than thicker, it is wise to leave them overnight. When dry, the polished surface may feel slightly gritty as a result of small particles of dust in the atmosphere settling on it. This can be remedied by using 0000 grade wire wool to reduce the overall sheen to a dull matt finish. However, make sure that the polish is only dulled and not removed, A cotton bud can often help to work the wire wool into smaller crevices.
Using a sanding block to smooth the surfaces without rounding over the edges.
Applying a wood stain with a brush.
Finally, apply a coat of paste wax polish, which is available in a range of complementary timber colours. It should be applied with a soft brush to ensure that the wax is distributed into the smaller and more awkward recesses. A tooth brush is particularly useful for this purpose. Then, after a short drying time, it can be buffed with a soft cloth to produce a deep and lasting shine. If the carving is to be located outdoors then a water resistant finish is required and, therefore, a wax finish will be unsuitable. Many of the exterior finishes tend to be thicker, so make sure you thin them down before applying them.
Applying wax with a toothbrush.
Occasionally it is desirable for a a carving to take on an antique look, enabling it to blend into its intended surrounding decor, It is fairly common to hear of craftspeople ‘distressing’ furniture using chains and nails to create random dents and scratches, thus creating the illusion of many years of wear and tear. Although chains and nails are rather brutal for carving, there are a number of other ways to create this appearance. Ageing techniques obviously vary according to the type of timber. However, there are three main factors which can help you to produce an aged effect.
More often than not the backs of old carvings have become very dirty and grey with age. One of the most sensible ways to replicate this appearance is to use old timber. Quite often it will have an old, dirty surface which has occurred naturally. By keeping one face of the timber un-planed you will have an authentic aged back for the carving. Another important consideration when using old timber is that it will be extremely well- seasoned and is quite likely to have deep splits and shakes. These features can also contribute to the antique look.
A collection of seventeenth century carvings and an example of an aged piece of timber planed on one side.
There are many products on the market which can change the colour of timber, whether it is to make it darker with stains or to lighten it it with bleaching solutions.
You should experiment with these products on a piece of scrap timber as there are few set rules.
Carving is an art form which naturally attracts admiring hands. Of course, many years of admiration as well as day-to-day knocks and scrapes will give the carving a rounded appearance, producing a shine on its most accessible areas. This can be replicated by rubbing the high spots of a new piece of work with a smooth hard object, such as a piece of metal, a stone or a burnisher as shown in the photograph below. The rubbing action creates burnished areas and also helps to round over prominent edges. A medium grade wire wool will also create this burnished effect.
APPLYING THE FINISH
As already described, certain areas of a carving are bound to suffer greater wear than others, producing variations of colour. On a new piece of work, which you want to take on an antique appearance or which needs to blend with an old carving, colour variations can be exaggerated after toning the carving with stains or bleach by rubbing the highlights with fine wire wool. This process will remove some of the colour, also leaving a a polished sheen. Following this, polishes may be added, or if a deep, subtle lustre is required, a paste wax can be applied directly on to the bare timber.
Using a burnisher on a wooden panel