How To: Use Wood Filler

How To: Use Wood Filler

Badly scratched hardwood flooring, rotted window frames, chipped furniture-common problems like these can be time-consuming and expensive to repair. Or they can be dealt with quickly and affordably by homeowners who know how to use wood filler. If you've never worked with this stuff before, get excited: It might soon be your favorite item in the toolbox. Simple in concept and easy to apply, wood filler works wonders to remedy surface imperfections in a vast, varied range of household items.

Which type of wood filler should you use? The answer depends largely on the job.

  • As the name suggests, stainable wood fillers are receptive to staining so that once you've applied the product, you can stain over it to ensure the repaired section matches the rest of the piece that you're fixing.
  • Typically, water-based wood fillers may also be stained (or painted), but unlike other products in the same category, these are specially formulated for use indoors. Common applications are molding, paneling, and cabinetry.
  • Heavy-duty solvent-based wood fillers are meant primarily for outdoor use and perform well on exterior siding and trim.

This guide to the best wood fillers should help you select one tailored to your project. Once you have the right supply, proceed with these steps for how to use wood filler so that your repair is nearly invisible.

MATERIALS AND TOOLS Available on Amazon
- Sandpaper
- Shop vacuum
- Tack cloth
- Wood filler
- Putty knife
- Polyurethane sealer
- Paint
- Wood stain

Keep in mind: Wood filler should only be used in superficial repairs for scratches and knicks, not damage that requires replacement.

At first blush, using wood filler may strike you as a messy process, but precise results are not only possible, they are in fact rather easy to achieve. It's important to note, however, that wood filler is intended strictly for superficial issues, such as scratches and gouges. If the damage calls for a proper repair, wood filler is no substitute. That said, there's no shortage of ways in which to use wood filler to improve the look of both practical and decorative elements that have seen better days.

STEP 1: Sand and clean the wood surface in need of repair.

Start by preparing the surface to which you are going to apply wood filler. For one, that means removing any loose chunks of wood or flaking paint. Next, sand any rough edges in or immediately adjacent to the damaged area you wish to repair. Finally, clear away all lingering dust and debris by means of a shop vac or moistened tack cloth (if you use the latter, wait for the area to dry completely before you proceed).

STEP 2: Apply the wood filler using a putty knife.

Start at the edge of the damaged area, pressing the wood filler into the depression. Overfill slightly to allow for the fact that the filler shrinks as it dries. Once you have applied as much filler as necessary, smooth over the filled area with a clean part of a putty knife.

STEP 3: Allow the wood filler to dry completely.

Check the packaging for manufacturer recommendations on how how much time is needed for the wood filler to dry. Depending on the depth of the application, that could take anywhere from 15 minutes to eight hours.

STEP 4: Sand the filled area so that its height is flush with the surrounding wood.

Once dry, work with a light hand to sand the area smooth. When you run your hand over both the undamaged and freshly filled parts of the item you are fixing, you should feel only the slightest difference between the two.

STEP 5: Complete the project by applying your choice of finish.

In most cases, the goal will be to make the repair virtually unnoticeable. So if you've been working on a baseboard painted white, concealing the fix is simply a matter of painting over the filled area in the same shade.

Stained pieces are trickier to deal with. For the best possible match, it's recommended that you dab some wood filler onto a piece of scrap wood. Wait for it to dry, then test the stain to see how it looks. Depending on the test results, you may then choose to thin out the stain, use a different color, or (if you got a close enough match) proceed to apply the stain to the item that you've now successfully fixed-cheaply, easily, and possibly in less than an hour.