Furniture Finish Repairs
    by Mitchell Kohanek


    Techniques for fixing common damage

    No doubt you have a favorite piece of furniture that bears a
    conspicuous scar from a careless smoker, a guest who didn't use
    a coaster for his drink, or a pet that doesn't share your
    appreciation of fine furniture. Every time you see the blemish, it
    probably rekindles ill will toward the perpetrator and makes you
    wish you could undo the damage.

    In fact, by using the right materials and techniques, you can fix
    many types of damage without spending a lot of time or money.

    You should realize, however, that repairing surface damage on
    furniture is a balancing act between technology and artistry.
    Although there are established techniques and materials used to
    repair finishes, an elevated sense of craft is an important part of
    achieving a successful result. Without it, a repair may be as
    noticeable as the damage it was intended to fix. While a restored
    area may never disappear, it should fall below the average
    person's threshold of perception.

    Typically, most repairs you'll make will be to manufactured
    household furniture. Nearly all household furniture manufactured
    since about 1920 was finished with lacquer. Although matching
    the color and sheen of a lacquer finish can be challenging, it is
    within reach. On the otherhand, handmade furniture
    (contemporary or antique) may require repair methods not covered
    here. And the materials and finishes used for modern office
    furniture can make repairs impractical.

    Star Finishing Products and other manufacturers (see SOURCES)
    make repair and retouching products that can help you achieve
    professional results. Keep in mind that this article can only point
    you to the right supplies and techniques - you'll need to furnish
    the talent.

    Easy Fixes

    Repairing minor damage, such as small scratches and water
    marks, requires only modest skill using familiar products. Small
    scratches, such as those produced by a cat's sharp claws, can be
    easily hidden using paste wax or an oil/varnish blend such as
    Watco Danish Oil. Always use tinted oil to match the wood color,
    and be sure to wipe off the excess. A finish that's dull from
    surface wear can be restored to its original sheen by polishing it
    with a rubbing lubricant and 0000 steel wool.

    You can usually remove cloudy water marks in the finish by
    rubbing the area with a rag dampened (not wet) with alcohol.
    Another method is to apply a thick coat of an oily substance such
    as petroleum jelly or mayonnaise on the mark and let it sit
    overnight. Generally, the oil will displace the moisture. Most water
    damage that has darkened the wood or caused the finish to
    separate from the wood will require stripping and refinishing.

    Touch - up markers made by Star, Behlen and Minwax work well
    for blending larger scratches. Putty sticks, such as Star Easy - Fil,
    are good for filling scratches, cracks and small dents and gouges.
    They can also be coated with almost any finish.

    More serious surface damage, including missing color (from being
    rubbed off) and problems caused by heat may require more
    drastic measures. Heat damage has a cloudy appearance similar
    to water marks. You can try to redissolve the finish with alcohol,
    but you'll probably wind up stripping and refinishing the piece.
    As for missing color, you can use padding lacquer and powdered
    stains, but more on that later.

    Using Burn-In Sticks

    Burn - in sticks (also called lacquer sticks), such as Star Nu - Glo,
    are used to fill larger damaged areas. To use them, the surface
    around the depression, dent or scratch should be relatively level,
    smooth and free of dirt. Remove any loose flakes of lacquer or
    wood fibers with sandpaper or a penknife. Note that it's more
    difficult to conceal a repair on a tabletop than on vertical surfaces
    such as legs. That's because color and sheen differences are
    much more noticeable on horizontal surfaces. Novices may
    therefore want to tackle something other than a tabletop on their
    first attempt.

    You'll need a burn - in knife (electric, gas or oven - heated) to melt
    the sticks. The knife's blade should be hot, but not so hot that it
    discolors the burn - in stick. The stick material should flow like
    cream without smoking or bubbling.

    The depth of the damaged area is a big factor when determining
    the color of the burn - in stick. Use an opaque color on shallow
    scratches that just penetrate the bare wood. On more deeply
    damaged areas where no color is missing, such as dents, use a
    clear transparent stick. Repairs made with transparent burn - in
    sticks tend to look good from all angles.

    To apply melted burn - in stick, pick up a small amount on the
    knife. Place the material ahead of the damaged area and pull it
    into the hole, overfilling slightly. With a little practice you'll develop
    the technique of dropping the material on the back stroke and
    pulling it into the hole on the forward stroke. Never stop the knife
    on the surface while applying or removing and leveling the burn -
    in area.

    Spread a lubricant, such as Nu - Glo Patch Lube, over the
    damaged area to pick up the excess patch material. Continue the
    stroke until you've picked up all of the excess or spread it into a
    very thin film.

    Replacing missing color

    You can repair areas of finish and stain that are worn through with
    padding lacquer (a type of shellac) and powdered stains. As
    always, be sure there's good cross ventilation when using
    finishing materials. First you'll need to apply the padding lacquer.

    Use a 4 - in. x 4 - in. piece of cheesecloth or lint - free cotton cloth
    to apply the padding lacquer. Fold the cloth in half, then into
    quarters. Gather the cloth corners at the rear to form a wrinkle -
    free pad surface.

    Moisten the cloth with padding lacquer and apply over the area
    using a swiping motion - much like a pendulum - making contact
    only at the bottom of the stroke (see photos, opposite). Don't stop
    the pad or you'll get a print mark. Confine the material to the
    smallest possible area around the defect. Continue until the
    surface is slightly tacky. On areas where bare wood is exposed,
    you should build up clear finish before adding color.

    You can blend powdered stains to obtain a matching color. To
    apply color, rub the stain powder onto the tacky finished surface
    with your fingertip. (Note that the padding lacquer will be tacky
    only for a few seconds after it's applied.) Then pass the tacky pad
    back and forth quickly to dissolve the powder into the finish. Don't
    use a pad that's too wet or it will lift the color rather than transfer it
    to the finish. Alternate between coloring and padding until you
    obtain the desired effect.

    Matching sheen is very difficult. You can attempt to match sheen
    with a can of aerosol lacquer. Spray the entire surface where
    you've made the repair. Then rub the surface with steel wool.

    To match grain, you can mix stain powders with graining liquid and
    then apply with a sable graining brush to match the appearance
    of the wood. Various types of wood will require different stain
    mixtures - more or less opaque - and brush sizes to match the
    wood's grain. An alternative method is to use a graining pen to
    draw grain lines.

    Mitchell Kohanek teaches Wood and Finishing Technology at
    Dakota County Technical College in Rosemount, Minnesota.
    Handy also thanks Bob Flexner, author of Understanding Wood
    Finishing, for contributing to this article, as well as Star Finishing
    Products for its technical assistance.

    Sources:

    Wood Finish Supply
    www.finishsupply.com


From the November - December, 2000, issue of HANDY magazine.
Copyright © 2001 Handyman Club of America