Standing in the wood repair aisle staring at tubes of filler and tubs of putty, most homeowners assume the products are interchangeable. They are not. Choosing the wrong one leads to cracked repairs, stain that will not absorb evenly, or patches that fall out within months. Understanding wood filler vs wood putty and when to use each saves you time, money, and a second trip to the hardware store.
What Is Wood Filler?
Wood filler is a thick paste made from wood fibers or sawdust suspended in a binding agent, typically a solvent or water-based resin. It hardens completely when dry, becoming a rigid solid that can be sanded, drilled, routed, and shaped just like real wood. Because it hardens, wood filler is designed for unfinished wood that will be sanded and stained or painted after the repair.
Popular products include Bondo Wood Filler, DAP Plastic Wood-X, and Minwax High Performance Wood Filler. These range from $6 to $15 for a container that covers multiple repairs. Two-part epoxy wood fillers like Abatron WoodEpox cost more ($25 to $40) but create the strongest, most durable repairs for structural damage like rotted window sills and door frames.
What Is Wood Putty?
Wood putty, sometimes called wood finishing putty, is a pliable compound made from calcium carbonate, oils, and pigments. It stays flexible after application and never fully hardens. This flexibility makes it ideal for finished wood, filling nail holes, small dents, and minor imperfections after staining or painting is complete.
Because putty remains soft, it moves with the wood as it expands and contracts with seasonal humidity changes. However, it cannot be sanded or shaped effectively. DAP Plastic Wood Finishing Putty, Minwax Color-Matched Wood Putty, and Colour Rite putty sticks are common options, typically costing $4 to $10.
Key Differences at a Glance
- Hardness: Wood filler dries rock-hard and sandable. Wood putty stays pliable indefinitely
- Timing: Apply filler before finishing (staining/painting). Apply putty after finishing
- Sandability: Filler sands smooth and accepts stain. Putty does not sand cleanly and resists stain absorption
- Flexibility: Filler is rigid and can crack in joints that move. Putty flexes with wood movement
- Hole size: Filler handles large gouges, holes, and rot. Putty is best for nail holes, small dents, and hairline gaps
- Indoor/outdoor: Most fillers work indoors and outdoors. Oil-based putties handle exterior use better than water-based ones
When to Use Wood Filler
Reach for wood filler when the repair happens before sanding and finishing. Common scenarios include:
- Filling nail and screw holes in trim that will be painted
- Repairing gouges, dents, and chips in bare wood furniture
- Rebuilding rotted sections of exterior trim, window sills, or door frames (use two-part epoxy filler for these)
- Filling gaps in edge-glued panels or tabletops before sanding
- Correcting defects in new hardwood flooring before applying polyurethane
For stained projects, choose a filler color that matches the wood species. Test on a scrap piece first, because filler absorbs stain differently than the surrounding wood. Mixing sawdust from the same project into the filler improves color matching significantly.
When to Use Wood Putty
Putty is a finishing touch, not a structural repair. Use it after the stain and topcoat are dry to address:
- Nail holes in stained or painted trim and baseboards
- Small dents or scratches in finished furniture
- Pin holes left by a brad nailer in finished crown molding
- Touch-ups on pre-finished hardwood flooring
- Minor cracks in finished outdoor wood furniture and decking
Select a putty color that matches the finished wood, not the raw wood. Most brands offer a range of colors from white and natural to walnut, cherry, and ebony. You can also blend two colors together for a custom match.
Application Tips for Best Results
Applying Wood Filler
Press filler firmly into the void with a flexible putty knife, overfilling slightly because all fillers shrink as they dry. For deep repairs over 1/4 inch, apply in two layers, letting the first dry completely before adding the second. Sand with 120-grit paper once dry, then finish with 220-grit for a smooth surface. Water-based fillers dry in 15 to 30 minutes; solvent-based types take 2 to 8 hours.
Applying Wood Putty
Press a small amount into the hole with your finger or a putty knife. Wipe away excess immediately with a clean cloth dampened with mineral spirits (for oil-based putty) or water (for water-based). No sanding is needed or recommended. Putty remains workable for several minutes, giving you time to smooth and shape the surface.
Common Mistakes to Avoid
Using putty on unfinished wood and then trying to stain over it is the most frequent error. The putty repels stain, leaving a visible light spot that looks worse than the original defect. Conversely, using filler on finished surfaces creates a rigid patch that stands out against the softer surrounding finish.
Another common mistake is applying filler in one thick pass on deep holes. The exterior dries and seals before the interior cures, trapping moisture inside. The result is a soft, spongy center that sinks over time. Build deep fills in layers no thicker than 1/4 inch each.
