Removing the Finish
When refinishing furniture, you must do the most unpleasant part of the job first. Removing the old finish can be a cumbersome and messy task. For a while early in the process, until you start getting down to the wood underneath the mess, you may feel that you have completely ruined the piece. Have patience. Once you get to the final stage of the wood, you will have graduated from making a mess to creating a masterpiece. When you’re finished, you’ll be proud of what you were able to create.
You can remove old paint and varnish in a couple of different ways, primarily by sanding and through the use of chemical strippers. Heat guns can also be used for stripping and are sometimes used as a supplement to the other methods in the removal of a particularly stubborn finish.
Sanding is a good method only if you have good sanding equipment and are experienced in its use. If you’re trying to remove an old finish by hand sanding or with a common orbital finishing sander, you’ll wear yourself out and waste a lot of sandpaper. On the other hand, belt and disk sanders can remove finishes quickly, but since they’re capable of removing so much material, you must be very careful not to ruin the piece by sanding too deeply. It’s also difficult to sand varnish from round or decoratively curved areas such as turned table legs.
Chemical strippers – commonly called paint strippers – are an effective means of removing paint and varnish from wood furniture or projects. Using these chemicals is probably the fastest and easiest method for most people. Despite what you may read on the back of a can, if you want to do a really good job, some sanding will still be required after the old finish is removed by the stripper.
Good to Know
The finish removal techniques described in this how-to will remove the rich patina of very old furniture. If your interest is in restoring antique or valuable old furniture, look first at products designed to clean and restore antique furniture without refinishing. Always test such products in an inconspicuous area before use. It may be that the old finish itself contributes to the value of the furniture.
As useful as they are, chemical strippers can be bad news if used improperly. Make sure you have adequate ventilation, rubber gloves and eye protection when using these substances. After all, they’re designed to soften, peel and blister paint and varnish. You don’t want them to do the same to your skin, lungs or eyes. Always follow the safety recommendations on the container.
Use strippers which require no cleanup or that will wash away with water. Statements similar to these will be on the label. The “no cleanup” type stripper may leave a residue which must be sanded away. Residue from the “wash away” type can be removed by rinsing with water. Be aware that water may swell the grain of the wood, requiring that the raised grain be lightly sanded.
Strippers come as liquids. Thicker formulations are referred to as gels, semi-pastes or pastes. Liquid strippers are only good for horizontal surfaces. For vertical surfaces, the thicker strippers are able to hang on better.
In general, the rules for using chemical strippers are as follows. Products may differ, so always follow the manufacturer’s directions for the product you choose.
Apply stripper to a manageable area. Put on a thick coat. Don’t disturb it once it’s applied.
Let the stripper sit for the time recommended by the manufacturer. Be patient and let it do the work for you. After the recommended time, test the finish with a putty knife. If it’s soft and the putty knife cuts through to the wood, you’re ready to go to the next step. Don’t wait so long that you let the stripper dry.
Remove as much paint or vanish as you can with a scraper or putty knife. Round the edges of your scraping tool to prevent it from gouging the wood. Follow-up with medium grade steel wool. Soaking the steel wool in the stripper may help remove stubborn spots. Some finishes, particularly enamels, will require multiple applications of stripper to get the job done.
Once you’ve removed as much finish as possible with the stripper, scrapers, and steel wool, follow the manufacturer’s directions for cleaning the stripper from the wood. Some products require that the stripper be removed with turpentine or paint remover. Others should be rinsed with water. Allow the piece to dry thoroughly.
Preparing the Wood
Once the piece is free of the old finish and has had time to dry, you’re ready to sand the wood. Depending on how good a job you were able to do with the stripper, you may not have a lot of sanding to do. Start with 120 grit paper to clean off any finish which may remain and to smooth out any bad places in the wood. Then smooth the whole piece down with 220 grit paper. Finishing sanders are particularly good for quickly achieving a uniform smoothness. When sanding by hand, be sure to sand with the grain.
The quality of your final finish depends largely upon the care you take when sanding. No amount of stain or varnish will correct a bad sanding job. In fact, stain will emphasize any rough places, swirl marks or other defects. Take the time to do a good job. It makes a big difference.
Filling the Grain
Some woods have a tight grain and don’t require grain filler. Others, like oak and mahogany, have an open grain structure that must be filled if you hope to achieve a smooth, even finish.
Grain filler comes as a pigmented paste in a range of colors. If you want to emphasize the grain of the wood, select a color that contrasts with the natural color of the wood or the color you intend to stain it. If you want to de-emphasize the wood grain, select a color that closely matches the anticipated finish color of the wood. You may want to test your planned finish on a piece of a similar wood. Use the filler, stain and final finish just as you plan to do on the project. This will let you see if you’re on the right track.
Grain filler may be applied before or after the stain. Consult the labels of the materials you’re using for their recommendations.
Use a rag or stiff paint brush to apply the paste filler. Work it into the grain and let it dry as instructed on the product packaging. Then, remove the excess filler with a plastic scraper or a smooth, round-edged putty knife. Hold the putty knife at a slight angle to the wood surface. Be careful not to damage the wood. Allow the filler to dry completely and lightly sand with the grain.
Applying Sanding Sealer
Applying sanding sealer is like priming the wood. The sealer reduces the tendency of some woods to absorb stain unevenly. Sealing end-grain prevents the wood from absorbing too much stain and creating very dark areas. Sealer can also be applied after staining and filling to reduce the number of finish coats.
Sanding sealers are available commercially. You can also create your own by thinning the material you intend to use for the final finish with an equal part of the appropriate thinner for that product.
Apply a heavy coat of sealer to your project. Allow it to soak into the wood for a few minutes. Wipe off any excess with a clean rag. Allow the sealer to dry completely before lightly sanding with fine (220 grit) sandpaper.
Choosing a 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 by lengthening the time the stain is allowed to penetrate the wood.
These stains do have a strong odor and must be cleaned up with mineral spirit type solvents.
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.
The major drawback of water-based products is that they can raise the grain of the wood. To minimize this possibility, dampen the wood with a moist rag. Allow the wood to dry completely. Finish sand again with fine sandpaper. Repeat the process. This conditions the wood to accept the water-based products with less raised grain.
Unlike liquid stains, gels are thick. They’re usually oil-based and allow excellent color control because of the thickness of the stain. They don’t swell the wood grain and can’t run like liquid stains. They do require that the wood piece be buffed between coats to remove any residual stain. Gel stains are also more expensive than liquid stains.
One Step Stain/Finishes
One step stain/finishes are popular because of their ease of use. After all, the color and finish are applied to the piece at the same time, eliminating several steps and possibly several hours of work. It can be more difficult to achieve a very good finish with these products. The finish itself is tinted so the color lies on top of the wood instead of being absorbed into it like penetrating stain. Thicker areas of finish will therefore have more color than thinner areas. Brush marks against the grain or other surface imperfections will be more evident in the final finish. Also, these finishes are less transparent and may obscure desirable grain characteristics.
Always follow the manufacturer’s recommendations for the product you’re using. In general, liquid stains are applied with a rag or brush and allowed to penetrate into the wood. The longer the stain is allowed to penetrate, the darker the color will be. However, this only works to a certain extent. The excess stain is then wiped off with a clean rag and the piece is allowed to dry. If a darker finish is desired, these steps are repeated.
Gel finishes are applied with a rag, rubbed on and wiped off as necessary to achieve the desired color and tone. The furniture piece should be buffed with a dry clean rag when the stain has been allowed to dry for the recommended time.
For best results when using water-based stains and finishes, follow the tips presented in water-based stains.
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 afford 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.
Water-based polyurethanes are becoming very popular because they’re easy to use and are environmentally friendly. They do require a different finishing technique. Before applying the finish, rub down the project 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’ve already used this technique when applying water-based stain.
If you’ve never used water-based polyurethane before, don’t be alarmed by the white, milky color of the product as it’s applied. It will quickly dry to a completely transparent clear. Unlike solvent-based finishes, it won’t lend an amber tint to the wood, which could be a positive, or a negative, depending on what you’re trying to accomplish. Water-based polyurethanes also dry quickly, requiring little time between coats.
Polyurethane is an extremely durable finish that’s 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 to keep the flattening agents in suspension. Avoid creating bubbles when stirring and when applying with a brush. After loading the brush, tap it 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. It’s a sure way to ruin your finish.
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 very 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. There is at least one product available which 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 doesn’t have the plastic appearance of many polyurethanes. The final coat can be rubbed out with 0000 steel wool and paste wax. It can also be polished with 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 that won’t be subject to a lot of wear and tear. Choose another type of finish if extreme durability is a requirement.
Oil finishes are applied to the wood and allowed to soak for a certain amount of time. Then any 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.
Watch our DIY Basics video: Do I Have Oil Or Latex Paint?