If you spend enough time in the shop, you eventually reach for something to patch a gap, cover a nail hole, or fix a chipped corner. The question is never “should I repair it?” but “what should I use?”
Wood filler and wood putty both live in the repair drawer, but they behave very differently once applied. This guide covers how each one works, when to choose one over the other, and what you can expect once the finish goes on.
What Wood Filler Is
Wood filler is a sandable, paintable repair material made to blend into raw wood. It is usually water-based or solvent-based and dries hard enough to take a stain or finish. In most cases, filler becomes part of the wood surface once it is dry, which is why woodworkers use it before applying any topcoat.
How It Works in Real Shop Conditions
Wood filler dries quickly and hardens, almost like the surrounding wood. That makes it ideal for interior furniture repairs, cabinetry, and pre-finish touchups. You can sand it flush, plane it lightly, and even route over it if you apply it correctly.
That said, wood filler does not flex. If the wood around it moves, expands, or contracts, you may later see hairline cracks, especially on outdoor projects or in wider gaps.
Best Uses for Wood Filler
• Nail holes
• Shallow dents
• Seams or joints that need blending
• Surface-level imperfections
• Pre-finish repairs on furniture and cabinets
In our experience, filler works best when the repair is small, controlled, and part of a finished piece that won’t be exposed to constant moisture.
What Wood Putty Is
Wood putty stays flexible and never fully hardens the way filler does. It is usually oil-based and is designed for use after the finish has been applied. That flexibility helps it expand and contract with the wood, which is why carpenters use it on trim and exterior pieces that see seasonal changes.
How It Behaves on Finished Wood
Putty is forgiving. If the wood shifts or a nail hole opens slightly, the putty moves with it rather than cracking. It is not meant to be sanded smooth or used under a finish. Instead, you match the color to the finish and press it into place as a final touch.
That said, putty is not structural. It fills small holes well, but it is not the right choice for rebuilding damaged corners or filling wide gaps.
Best Uses for Wood Putty
• Nail holes in stained trim
• Touchups after topcoat
• Small gaps in casing or baseboards
• Outdoor wood that sees moisture and temperature swings
• Repairs where flexibility matters more than sanding
If you ever repaired door or window trim and wanted a repair that stays put through the seasons, putty is usually the answer.
Wood Filler vs Wood Putty: Choosing the Right One
Here is the decision most woodworkers make after years of trying both.
When to Pick Wood Filler
If the wood is raw, the repair needs sanding, and you will apply stain or finish afterward, filler is the safe choice. It becomes part of the wood surface, giving you a clean, flush repair.
When to Pick Wood Putty
If the finish is already on, or the project is exposed to humidity or seasonal changes, putty performs better. It stays flexible and hides holes without cracking.
Workshop Transition
That said, if you’re fixing something structural or rebuilding a corner, neither filler nor putty is ideal. At that point, epoxy or a structural repair method is the better path.
Side-by-Side Comparison Table
| Feature | Wood Filler | Wood Putty |
|---|---|---|
| Application | Before finishing | After finishing |
| Hardness | Dries hard | Stays flexible |
| Sandable | Yes | No |
| Stainable | Yes (water-based and solvent-based types) | Not designed for staining |
| Indoor or Outdoor | Mostly indoor | Indoor and outdoor |
| Best For | Nail holes, dents, pre-finish repairs | Finished trim, minor touchups, moving wood |
| Cracking Risk | Higher on moving wood | Low due to flexibility |
Final Thought
Choosing between wood filler and wood putty becomes second nature after a few projects. Filler is the tool for clean, sanded, pre-finish repairs where you want the patch to disappear into the wood.
Putty steps in after the finish is applied, especially when you want a repair that can flex with seasonal movement. Once you understand how each behaves, you’ll know exactly which tub to grab for every job in the shop or on site.
For more background on how wood moves and behaves under different conditions, the USDA Forest Products Laboratory offers helpful explanations.
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