How to Restore the Finish on Wooden Furniture

Before beginning the restoration of a piece of furniture, it’s crucial to identify the type of finish it has. If you’re unsure, you might end up ruining a good finish or wasting your time on an ineffective method. This knowledge is also key for repair tasks, especially when you need to match one finish with another. For restoration, the most important distinction is between the three primary clear or natural finishes: shellac, lacquer, and varnish.

Pigmented finishes, such as paint or enamel, are easy to identify. The other finishes you might come across include oil, wax, and penetrating sealers, which can be recognized by touch and their lack of a high gloss. These finishes can only be restored through reapplication. Most furniture typically has a clear finish from one of the three basic types: shellac, lacquer, or varnish.

Before beginning any work on the finish, it's essential to identify it. Start by testing the finish with denatured alcohol; apply a small amount of alcohol to an inconspicuous area. If the finish dissolves, it's shellac. If it partially dissolves, it’s likely a mixture of shellac and lacquer. Repeat the test using a blend of denatured alcohol and lacquer thinner; this should completely dissolve the finish. If alcohol doesn’t affect the finish, try lacquer thinner on an inconspicuous area. If the area becomes rough and then smooth again, the finish is lacquer. If the finish wrinkles and doesn’t smooth out, it’s varnish. If neither alcohol nor lacquer thinner affects the surface, the finish is varnish.

Once you’ve identified the finish, you’re ready to restore it. Whether the issue is dirt, cracks, discoloration, or general wear, there are several restoration methods that can often resolve these problems.

Cleaning Methods

The simplest restoration method is cleaning. What seems like a damaged finish could actually just be built-up dirt. Over the years, even well-maintained furniture can develop a dull, sticky layer of wax and dust. In many cases, this layer can be removed with an oil-based wood cleaner/conditioner. These cleaners cut through dirt and wax and are available at furniture stores, supermarkets, and paint shops.

Follow the manufacturer’s instructions to apply the cleaner generously with a soft cloth, letting it sit for an hour or two. Wipe off the cleaner with a clean cloth. Repeat the process, using plenty of cleaner, until the wood looks clean and shiny. This may take four or five applications. Gently buff the wood to remove any excess oil.

If a commercial cleaner/conditioner doesn't do the trick, try removing the accumulated grime with a mild mixture of warm water and liquid detergent. Use it sparingly and work quickly, avoiding soaking the furniture or pouring the solution directly on it. Water can cause a white haze to form on shellac or lacquer finishes, similar to the ring left by a glass on a table. After cleaning, rinse the detergent off with water and thoroughly dry the wood with a soft cloth or towel.

Allow the wood to fully dry. If any haze remains on the finish, you may be able to buff it out with steel wool. Lightly rub the surface in the direction of the wood grain using No. 0000 steel wool. Then apply a commercial cleaner/conditioner and buff the wood lightly once more.

If detergent cleaning fails, turn to a solvent based on the finish type to clean the wood. Solvent cleaning should be a last resort, as it could damage the finish. Use mineral spirits or turpentine for any finish, but use denatured alcohol for varnish or lacquer finishes. Avoid using alcohol on shellac or shellac/lacquer mixtures. Always work in a well-ventilated area, preferably outdoors, applying the solvent with a rough cloth like burlap or an old towel. Wipe the wood clean with a separate cloth, then apply a commercial cleaner/conditioner and buff lightly.

Detergent and solvent cleaning methods can also be used to refresh wicker and rattan furniture. Follow the same procedures mentioned above, but be extra cautious with water usage. Allow the furniture to dry completely, preferably in the sun. If the finish is very thin or worn, apply one or two coats of spray varnish, spraying evenly over the wicker or rattan. Let the new finish dry for a few days before using the furniture.

If your furniture finish is cracked, scratched, or showing an alligator-like texture, there’s another technique in the next section to restore it to like-new condition.

Rejuvenating an Old Finish

Reamalgamation is a powerful restoration technique that can make damaged finishes—such as alligatoring, crazing, cracking, or scratching—look brand new. Essentially, reamalgamation involves liquefying the damaged finish so it can dry solid and smooth. It’s a simple and effective process that can save you from having to completely refinish the piece. And if it doesn’t work, you haven’t invested too much time or effort.

Alligatoring, crazing, and cracking are all essentially caused by sunlight or temperature fluctuations, and they can all be treated with reamalgamation. Alligatored finishes have intersecting fine cracks creating a rough pattern, crazed finishes have erratic, random cracks, and cracked finishes have wider lines or sometimes just a single crack. Scratches can also be reamalgamated if they don’t go past the finish itself; deeper scratches in the wood will require refinishing of that area.

The solvent used for reamalgamation depends on the type of finish. Shellac is reamalgamated with denatured alcohol, lacquer with lacquer thinner, and a lacquer/shellac mixture with a blend of three parts alcohol and one part lacquer thinner. Varnish generally cannot be reamalgamated.

Before starting work on the finish, thoroughly clean the furniture with mineral spirits or turpentine to remove any wax and dirt. Avoid working on a very humid day if the finish is shellac; the alcohol used to liquefy shellac can draw moisture from the air into the finish, causing a haze or 'blushing'.

The key to successful reamalgamation is to work quickly, especially with lacquer. Start by testing a small section to get the hang of the process; once satisfied, move on to reamalgamate the whole surface. Apply a moderate amount of solvent using a fresh, clean natural-bristle brush. You can either buy a store-bought amalgamator or make your own. Use denatured alcohol for shellac, lacquer thinner for lacquer, and a three-to-one mix of alcohol and lacquer thinner for a lacquer/shellac blend.

To reamalgamate the surface, apply solvent along the wood grain in quick, smooth strokes. Be swift and avoid letting the brush dry out. Don’t focus on individual cracks or scratches yet; many will fade as the finish dries. Overworking individual marks could actually remove the finish instead of liquefying it.

As the solvent begins to dry, the finish will initially appear glossy. After about 30 minutes, it will turn dull. If the reamalgamation has worked, any scratches or imperfections will have vanished, leaving the finish looking solid.

Reamalgamation may require more than one application. If the cracks are deep, it could take two or three rounds of solvent to remove them. If repeated reamalgamation doesn’t work, the issue likely lies in the wood itself, and you’ll need to refinish the area.

Once the reamalgamated surface has dulled, gently buff the finish using No. 0000 steel wool, always working along the wood grain. Apply minimal pressure, simply polishing the finish. Next, wipe the surface clean with a fresh cloth. If the reamalgamated finish is thin, use a tack cloth to clean the surface before applying a new coat of the same finish directly over the old one. Allow the finish to dry, lightly buff it with No. 0000 steel wool, then apply a hard paste wax and buff it with a clean cloth.

Restoring a Discolored Finish

Blushing, which is a cloudy or milky discoloration in the finish, is a common issue with shellac finishes and can also affect lacquered wood. Varnish finishes are not prone to blushing. This issue is typically caused by moisture, whether from prolonged humidity, exposure to water, or simply age. If the blushing isn't too deep, it might be removed with No. 0000 steel wool and oil or by reamalgamating the finish. However, if the blushing is deeply set, the only solution is to refinish the wood.

If blushing occurs on an alligatored or cracked finish, try reamalgamation first. This may remove the blush and also smooth out the cracks. If the finish is not cracked, or if reamalgamation fails to remove the blush, use steel wool to address the discoloration.

Before starting, ensure the surface is clean by removing any wax and dirt with mineral spirits or turpentine. Then, dip No. 0000 steel wool in mineral oil, linseed oil, or salad oil and gently rub along the grain. Move slowly, keeping the steel wool well-oiled throughout the process. The steel wool will abrade the top layer of the finish, leaving a fresh finish behind. Once done, dry the wood with a soft cloth and apply a hard paste wax, polishing it afterward. If the blushing is only on the surface layer -- which it often is -- this technique should work. Otherwise, a full refinishing will be necessary.

What should you do if the finish on your furniture begins to wear away? We will explain how to apply a fresh coat over a worn finish in the next section.

Re-coating a Worn Furniture Finish

Over time, materials inevitably wear down, and furniture is no exception. Sometimes the entire finish wears away, and at other times, only heavily used areas show wear, typically around drawers and doors. On antiques, this wear is part of the piece's patina, which helps to date and assess its value, and should not be covered or restored.

This principle holds true for nearly all furniture: wear and tear imparts character. However, if the finish is thin or worn, you can apply a new coat. In cases where refinishing is necessary, it is often possible to repair just the worn areas.

Start by cleaning the surface thoroughly using mineral spirits, or, if dealing with lacquer or varnish, denatured alcohol. If the entire finish is worn, clean the whole piece to remove all dirt and grease. After cleaning, apply a fresh coat of the same finish that's already on the wood.

When touching up worn spots rather than re-coating the entire piece, clean the affected area and gently sand the worn spots with fine-grit sandpaper. Avoid applying too much pressure.

Once the wood is exposed, it needs to be refinished. If the piece isn't stained, this is simple; however, if it is stained, you'll need to restain the bare areas to match the rest of the piece.

To repair the worn spot, use an oil-based stain that matches the existing stain on the furniture. You may need to blend stains to achieve a good match. Always test the stain on an inconspicuous, unfinished area before applying it to the worn spots.

Apply the stain to the damaged area using an artist's brush or a clean cloth, ensuring complete coverage of the bare spots. Allow the stain to sit for 15 minutes, then wipe it off with a clean cloth. If the color is too light, add another layer of stain, wait 15 minutes, and wipe again. Repeat until you're satisfied with the color. Allow the stain to dry according to the manufacturer's guidelines.

Gently buff the stained area using No. 0000 steel wool, then wipe it clean with a tack cloth. Apply a fresh layer of the same finish that was previously on the surface—whether it's lacquer, shellac, penetrating resin, or varnish—feathering it out into the surrounding original finish.

Allow the new finish to dry for one to two days. Afterward, lightly buff the touched-up areas with No. 0000 steel wool. Finally, apply a coat of hard paste wax to the entire surface and polish it to achieve a smooth shine.

Alternative Ways to Decorate an Old Finish

Restoration techniques like cleaning, reamalgamating, spot patching, or using steel wool can improve the appearance of old furniture, but they don't always succeed. If the original finish is still in good condition, you can often rejuvenate an old, dull piece of furniture with decorative touches or unique finishing effects. If the finish is damaged, enamel can be used to cover it completely instead of doing a full refinish. Before removing the old finish, explore your options—you may not need a complete overhaul to breathe new life into an old piece.

Special finishing effects can transform a dull piece of furniture. Techniques like antiquing, flyspecking, stenciling, decals, and adding painted stripes can enhance the charm and appeal of many pieces, particularly country-style furniture. If you're aiming for a bold, distinctive accent, an enamel finish might be the solution. Enamel can be applied over an old finish, covering flaws and providing a great base for further decoration.

While it's rare for anything to be completely flawless, applying some of the techniques shared in this article will provide you with a simple way to bring new life to the worn finish on your furniture.

Publications International, Ltd.