Some wood filler may be needed before applying a fresh coat of paint to the interior woodwork. Unsightly holes, gouges, scratches, and dented corners can result from normal wear and tear of everyday life. This is especially apparent in older homes where the woodwork may have been painted over and over again without any fill repairs. The good news is that damaged wood trim can be restored to look as good as new. This type of preparation can be time consuming, so you should only do as much as your time or budget allows.
Polyester Wood Filler
Using appropriate filler is the key to successful wood restoration. Spackling paste is sufficient for unfilled holes but it is inadequate for many types of wood fill applications.
Two part polyester wood filler works well as an all purpose filler. It can be used as a surfacing compound to fill shallow scratches such as those caused by dogs. Topping over under-filled nail holes is another good example that requires a strong surfacing compound.
Polyester filler can be used to repair broken and dented corners, damage often caused by moving furniture. Unlike spackle, polyester filler dries hard so it can be sanded to match the profile of the surrounding wood
Catalyzed filler such as polyester wood filler also performs well to fill holes and gouges in woodwork. Because many two part fillers do shrink to some extent, holes should be slightly overfilled. Larger voids may require more than one coat of filler.
Two part fillers consist of filler paste and cream hardener (catalyst). These types of catalyzed products require mixing the correct ratio of the two parts. If the two parts are not mixed, the filler paste will not dry. I frequently use the Evercoat 400 Polyester Glazing Putty along with its corresponding cream hardener. This product is available in 20 ounce cans.
Mixing the filler paste with the cream hardener can be done on a smooth, flat surface. A small piece of plastic or wood that is free from contaminants will suffice. Once the filler paste is mixed with the cream hardener, it will dry within a few minutes, so just mix a small amount of material to avoid waste. Mix about a teaspoon of filler at a time for optimum workability. The filler paste and hardener are easily mixed together with a small flexible putty knife. Always follow product label instructions for proper mixing ratios.
Apply the catalyzed filler to the damaged areas of the woodwork with a small flexible putty knife. A one inch knife works well for most applications. A larger flexible putty knife may be preferable for large areas of scratches. Be sure to slightly overfill the damaged areas. Once the filler is dry, it can easily be sanded with 150 grit sandpaper to perfectly match the profile of the wood surface. Feather sand the edges of the fill spots so they are not visible after paint is applied.
Before applying the finish coats of paint to the woodwork, the wood filler should be spot primed. A quick and easy method of spot priming is with a spray can of interior primer. The fast dry oil base primers are very convenient for this task. After vigorously shaking the spray can for about a minute, it is ready for use. A quick shot of primer on each fill spot is sufficient. The best part is that there is no clean-up. Once the primer is completely dry, lightly sand the primer spots with 320 grit sandpaper. You may also choose to spot prime with a brush and a water base or oil base primer.