Whether you’re building furniture or picture frames, installing new trim or refinishing your favorite table, one of the keys to success is applying a beautiful finish.
No matter what you will be applying finish to, the wood surface must be clean and smooth.
The easiest way to accomplish this is by sanding, either by hand or with a power sander. Hand sanding is best for small projects, tight spaces and intricate details. However, if you’re working with a large, flat wood surface, such as a table top or even a floor, your best option is a random orbit sander.
To create that perfect surface, start with coarse grit sandpaper and progressively use finer grits – the higher the grit number, the finer the sandpaper. If the wood isn't too rough, then start with a medium grit – an 80 or 100 grit paper - then work your way up to fine – 150 or 180 grit - and then extra fine - 220 grits. When building a project from scratch, it’s often easiest to do the initial medium and fine sanding of the parts before assembling them – when it’s easy to get at all sides.
After sanding, remove the sanding dust with a vacuum or brush and then wipe the piece down with a dry rag. Now that the project is smooth and clean you’re ready to apply the stain.
If you're refinishing furniture, you're almost certainly going to be using stain to achieve the color you desire and to reduce the contrasts between different wood varieties which may have been used in the construction of the furniture. There are several different types of stains and dyes which may be used to color wood.
Liquid oil-based stains penetrate into the wood without raising the wood grain. They're permanent and when properly used, yield very good results. The color can be darkened by multiple applications and lengthening the time the stain is allowed to penetrate the wood.
Liquid water-based stains are more environmentally friendly than traditional oil-based products. As with oil-based stains, you can deepen the color of the stain with multiple applications. Water-based stains are convenient and require only a soap and water cleanup.
One Step Stain/Finish
One step stain/finishes are popular because of their ease of use. The color and finish are applied to the piece at the same time, eliminating several steps and possibly several hours of work.
The biggest hurdle to overcome is achieving an even color without blotching. Prior to staining, it may be necessary to apply conditioner. A conditioner preps the surface of wood, particularly soft or porous woods such as pine and alder, to receive a coat of stain more evenly. It dries quickly, so applying it won’t cause you to lose much time. Fortunately, there are new liquid stains that work well without a conditioner. They'll even work with difficult to stain woods, such as maple. Other stains require the use of a conditioner. Follow the manufacturer instructions before applying the stain.
In general, stains are applied with a rag or brush and allowed to penetrate into the wood. Coat an area that you can cover in no more than five minutes. Once the area is coated, wait 1-2 minutes. The longer the stain is allowed to penetrate, the darker the color will be. The excess stain is then wiped off with a clean rag and the piece is allowed to dry. If a darker finish is desired, multiple coats can be applied.
Your choice of top coating is a matter of personal preference. Penetrating oil finishes are easy to apply and look great with a soft, natural appearance. They offer less protection than varnish or lacquer finishes. Polyurethane creates a hard, durable finish and is available in a range of sheens. Water-based polyurethanes are very easy to use and are environmentally friendly. Lacquer gives a durable and luscious finish, but requires more skill and effort to apply. Your decision about which finish to use will depend on your confidence level and the piece you're finishing.
Polyurethane is an extremely durable finish that is resistant to both water and alcohol. It's available in a range of sheens to help you achieve the look you desire. When using satin or semi-gloss formulations, be sure to stir the product well. Avoid creating bubbles when stirring and applying with a brush. Tap the brush lightly against the side of the can instead of dragging it across the lip.
Brush polyurethane with the grain in long, overlapping strokes. Apply several thin coats, sanding between coats with 220 grit paper.
One of the most common mistakes people make when using polyurethane is trying to apply thick coats. This can cause running, wrinkling and sagging, which can ruin your finish.
Water-based polyurethanes are becoming popular because they're easy to use and are environmentally friendly. They do require a different finishing technique. Before applying the finish, rub the piece with a damp cloth. Allow the wood to dry and then sand to remove the raised grain. You may want to do this a couple of times to reduce the tendency of the water in the finish to raise the grain when it's applied. This should be unnecessary if you have already used this technique when applying water-based stain.
This marine-quality finish remains flexible and will expand and contract to outperform traditional polyurethane in harsh conditions. The durable finish is U.V. and weather resistant, making it an ideal choice for exterior wood doors, window sills and trim.
Lacquer can be used to achieve a beautiful finish. Lacquer is considered more difficult to apply than other clear finishes because it requires several coats with sanding in between. It dries quickly and is usually sprayed rather than brushed. It can't be used over paint or other topcoats since it will soften and lift the finish.
For the best finish, lacquer should be sprayed. Use a product that combines a lacquer base with a sealer in an easily applied topcoat which can be sprayed or brushed. If you use a brush, work quickly and apply lacquer with the grain using a good, natural bristle brush.
A properly applied lacquer finish is a thing of beauty worthy of the finest furniture. A hand rubbed lacquer finish has a deep, soft gloss and does not have the plastic appearance of many polyurethanes. The final coat can be rubbed out with 0000 steel wool and paste wax, or you can use a polishing compound (automotive compound is fine) for a soft luster.
Penetrating Oil Finishes
Penetrating oil finishes are easy to apply and produce handsome results. "Tung oil," "Danish oil" and "Antique oil" finishes fall in this category. They're good choices for antiques or fine furniture which will not be subject to a lot of wear and tear. Choose another type of finish if extreme durability is needed.
Oil finishes are applied to the wood and allowed to soak for a certain amount of time. Then the excess is removed by rubbing and buffing with a rag. Several coats are applied.
Small scratches and defects can be easily repaired by simply sanding the defect and rubbing more oil finish in the affected area. The entire finish can be renewed periodically by rubbing in an additional coat. It's also a good idea to use paste wax on furniture finished using penetrating oils. The wax will give additional protection while complementing the appearance of this finish.