Wood finishing is one of the last steps in a woodworking project. Surprisingly, however, the finish can make a big difference in how the final project looks and feels. You can spend hours creating a beautiful piece of furniture, but if the surface is rough or unfinished, the whole thing will look less impressive. A finish does more than just change the color of wood. Depending on what kind of finish you use, it can highlight the grain of the wood, enhance the color, even out the surface, offer protection, and make maintenance easier. Often, you will get the best results from careful preparation rather than layering on finish after layer of finish.
Start With a Well-Prepared Surface
Before you decide whether to apply oil, stain, paint or varnish, make sure the wood itself is properly prepared. A finish won’t mask every flaw. Scratches, dents, uneven edges, and machine marks may actually be made worse by the finish.
Look over the entire surface with good lighting, running your hand over the wood to detect rough areas. However, do not rely entirely on your sense of touch; there are scratches that may not be very noticeable to the touch but will show up clearly after the finish is applied. Take your time during this stage. It’s not the most exciting part of a project, but a lot can hinge on how the surface is prepared.
Sanding the Wood
Sanding evens out the surface and eliminates tool marks that were created during the cutting and shaping process.
Choose an abrasive that is suitable for the condition of the wood. If there are deep marks, you may need to start with a coarse abrasive. On the other hand, if the board is already relatively smooth, you may not need to sand as hard or as much. As you sand, work towards finer abrasives.
Do not just sand for a set amount of time. Look at the surface at each stage and continue sanding until the scratches and imperfections that you saw before sanding are gone.
Sand Along the Grain
Wherever possible, sand in the direction of the grain.
If the surface is sanded against the grain, cross-grain scratches will be clearly visible after finishing, especially if you’re using a clear finish. Apply steady pressure and try to sand each section evenly. It can be easy to apply too much pressure to one spot and sand too deeply.
Clean Dust From the Surface Before Finishing
When you’re done sanding, the surface must be clean.
Fine dust particles can settle in the pores, corners, and along the edges. If they become trapped under the finish, they may affect the texture and appearance of the finish. Carefully remove all dust and check the wood again under good lighting.
If you find any remaining scratches, sand more rather than continuing with the finish and hoping the surface will improve as it dries.
Choosing the Right Finish
No single finish works for every project.
The right finish depends on the type of wood being worked with, the function of the item, the appearance you want to achieve, and the degree of protection needed. Some finishes highlight the natural look of the grain. Others alter the color or provide a more even surface. Decide how the finished piece will be used before you make your choice.
Oil Finishes
Oil finishes are frequently selected to highlight the natural look of the wood. They add richness to the color, enhance the visibility of the grain and provide a relatively natural appearance. These types of finishes are especially appealing on decorative items and furniture where the look of the wood is an essential part of the aesthetic. Different oils have different properties so always use the specific product as directed.
Stains and Color
Stains alter the color of the wood but let much of the natural grain show through. This can be helpful if you want a certain color or want several pieces to have a consistent appearance. Keep in mind that stains don’t produce the exact same look on all woods. Some species of wood absorb stain more uniformly than others and there can be variation in the way the grain absorbs stain.
Test Your Finish First
Perhaps the most important habit to develop when finishing is testing the finish on a piece of scrap first. Whenever possible, use a scrap of the same wood. Apply the finish and let it dry as instructed. This provides a far better preview of the color and finish than looking at a picture on the package. The small effort it takes to test a finish can save you from a disappointing outcome later.
Clear Protective Finishes
Clear finishes are helpful if you want to protect the wood without changing its appearance. Some clear finishes offer varying degrees of sheen. You can select from almost a matte finish to a high gloss. Your choice of sheen can also help determine the character of your piece. A satin or matte finish looks understated and natural, whereas a high gloss looks more formal and dressy. Consider the style of your project before settling on the shiniest option.
Application of the First Coat
When you’re ready to start the finishing process, don’t rush. Follow the instructions for application, drying time, ventilation and preparation. Apply a thin, even coat of the finish rather than trying to cover the entire piece in one layer. Some finishes perform best when applied in several thin layers.
Watch the Edges
Edges absorb differently from larger flat surfaces. You can get uneven coverage or accumulate excess product along the edges. Pay close attention to corners and end grain as you apply the finish. Patience and control yield better results than speed.
Give It Time to Dry
One of the most common finishing mistakes is recoating or handling a piece before it has dried completely. The surface of a finish can feel dry long before the underlying layers have cured. Follow the drying and recoating time recommendations rather than relying on how the surface feels. The temperature, humidity, ventilation, and type of product will all affect the drying time.
Being patient here can make a big difference in the outcome.
Sanding Between Coats
Some finishes require a very light sanding between coats.
This can help to smooth out small imperfections and give a more uniform surface for the next layer.
However, how you do this will depend entirely on what type of finish you’re applying.
If the manufacturer recommends sanding between coats, then use a suitable fine abrasive and don’t take off any more material than you need to.
Then clean the surface again before applying the next coat.
Don’t try to fix every imperfection
There’s no need for a handcrafted wooden piece to look as though it has come from a factory.
Small variations in the grain, slight differences in colour, and other minor imperfections are part of the charm of working with wood.
The aim of finishing is to enhance and protect the piece, not to hide every indication that it’s made from a natural material.
Understanding what flaws are acceptable and what should be addressed is a valuable skill that will develop over time.
Consider the intended use
The use of the piece will dictate the choice of finish.
A piece that will sit on a shelf won’t have the same demands as a tabletop or a storage box that will be handled often.
A piece that will be subjected to regular moisture exposure or heavy use may require a finish that is designed for these purposes.
Think about longevity as well as aesthetics.
An attractive finish that is not suited to the conditions could become damaged quickly.
Think about maintenance
A finished piece may not be maintenance-free forever.
Over time, some finishes can become dull, scratched or worn, depending on how they are used.
Knowing how a finish should be maintained can inform your choice at the outset.
For pieces that will be kept for a long time, maintenance needs can be just as important as the initial appearance.
Give the project time
Finishing can be one of the most rewarding parts of woodworking because it’s when you get to see the true character of the material.
But it’s also the part that can teach you patience.
Give every stage its proper amount of time. Don’t sand too lightly just to see the final colour sooner, and don’t apply another coat just because the last one appears to be dry.
The piece you finish is the culmination of every step that led up to it.
Final thoughts
A good finish starts with good workmanship and preparation.
Spend time looking at the surface, sanding carefully with the grain, and cleaning away all dust and debris. Choose a finish that is compatible with the material and suited to the project. Above all, experiment with unfamiliar products before using them on the final piece.
With experience, you’ll find that finishing is not just a set of steps to complete. It’s a way of understanding how materials behave and interact. This understanding will allow you to produce wooden items that not only look great when they come out of the workshop, but continue to look and feel great for many years to come.