If you’ve ever worked on a woodworking project or tried to fix imperfections in wooden furniture, you’ve probably faced the big question: wood putty or wood filler? Knowing when to utilize each of these two things will help you save money, time, and effort. Let’s examine closely the variations, applications, and best practices for these important wood repair tools.
What Is Wood Putty ?
Definition of Wood Putty
Wood putty is a soft, paste-like material used to fix small wood problems. It is usually made with either an oil-based or water-based formula and works well for filling tiny flaws like nail holes or light scratches. Unlike wood filler, wood putty stays a bit flexible after it dries, making it better at handling the slight movements of the wood as it expands and contracts.
Common Uses of Wood Putty
Wood putty shines when used on finished wood surfaces, like varnished furniture or painted woodwork. It’s great for patching small cracks, nail holes, or minor dents on surfaces that are already treated and finished.
Types of Wood Putty
Wood putty comes in several types, each with unique properties suited for different applications. The three common types of wood putty are:
1. Nitrocellulose-Based Wood Putty
Drying Time: Dries quickly, typically within 5 to 10 minutes.
Cleaning: Requires acetone or lacquer thinner for cleanup before it cures.
Usage: Ideal for urgent projects where quick repairs are needed.
2. Water-Based Wood Putty
Drying Time: Takes up to 24 hours to dry.
Cleaning: Can be easily cleaned with water.
Usage: Suitable for projects that allow for longer drying times; preferred for indoor applications due to its ease of use and cleanup.
3. Oil-Based Wood Putty
Drying Time: Generally takes about 48 hours to fully dry.
Cleaning: Requires oil solvents like turpentine for cleaning.
Usage: Often used for outdoor applications due to its durability and flexibility, making it effective in areas prone to temperature changes.
Summary of Properties
| Type | Drying Time | Cleaning Method | Best For |
| Nitrocellulose-Based | 5-10 minutes | Acetone or lacquer thinner | Quick repairs |
| Water-Based | Up to 24 hours | Water | Indoor projects |
| Oil-Based | Up to 48 hours | Oil solvents (turpentine) | Outdoor projects |
What Is Wood Filler ?
Definition of Wood Filler
Wood filler is a substance used to repair and rebuild damaged or missing wood. Made from a mixture of wood fibers, resins, and binders, it creates a solid surface that can be sanded, painted, or stained.
Common Uses of Wood Filler
Wood filler is perfect for filling larger gaps, cracks, or holes, especially in unfinished wood. It’s commonly used to prep wooden surfaces before applying paint or stain.
Types of Wood Filler
Wood filler is an essential material in woodworking, used to repair and fill imperfections in wood surfaces. There are several types of wood fillers available, each with unique properties suited for different applications. Here’s a breakdown of the main types:
1. Water-Based Wood Fillers
Composition: Made from wood glue mixed with wood fibers and additives.
Characteristics: Easy to clean up with soap and water; can be rehydrated if it dries out.
Usage: Best for indoor projects, as they are not suitable for areas exposed to moisture. They may not stain evenly compared to surrounding wood.
Examples: Minwax Stainable Wood Filler, DAP Plastic Wood Latex.
2. Solvent-Based Wood Fillers
Composition: Often contains wood fibers mixed with a solvent-based resin.
Characteristics: Durable and suitable for larger gaps; dries hard and can be sanded.
Usage: Ideal for both interior and exterior applications due to their strength and moisture resistance.
Examples: DAP Plastic Wood Professional, Famowood Original Wood Filler.
3. Epoxy Wood Fillers
Composition: Two-part system consisting of a filler paste and a hardener.
Characteristics: Extremely durable and water-resistant; bonds well with surrounding materials.
Usage: Suitable for filling large voids or structural repairs, particularly in outdoor settings where moisture exposure is a concern.
Examples: Bondo Wood Filler, West System Epoxy.
4. Two-Part Wood Fillers
Composition: Similar to epoxy fillers, these consist of a filler paste combined with a hardener.
Characteristics: Sets quickly and creates a strong bond; ideal for large repairs and structural integrity.
Usage: Can be used indoors and outdoors; often not stainable but sandable.
Examples: Minwax High Performance Wood Filler.
5. Specialty Fillers
Grain Fillers: Used specifically for filling the grain of flat surfaces like tabletops before finishing.
Rotted Wood Stabilizers: Designed to prepare damaged areas before applying other fillers.
Summary of Properties
| Type | Composition | Durability | Best For |
| Water-Based | Wood glue + wood fibers | Moderate | Indoor use |
| Solvent-Based | Wood fibers + solvent resin | High | Interior & exterior |
| Epoxy | Two-part system | Very high | Large voids/structural |
| Two-Part | Filler paste + hardener | High | Large repairs |
| Specialty | Various (grain fillers, etc.) | Varies | Specific applications |
Also read: Tung Oil vs. Danish Oil: A Comprehensive Comparison
Key Differences Between Wood Putty and Wood Filler
Wood putty and wood filler are both used in woodworking to repair and fill imperfections, but they have distinct characteristics and applications. Understanding these differences can help you choose the right product for your project.
Composition
Wood Putty: Typically made from synthetic materials, including plastic chemicals and oil-based compounds. It remains pliable after application, which allows it to expand and contract with the wood.
Wood Filler: Composed of wood particles or fibers mixed with a binding agent that hardens upon drying. This composition allows it to provide a solid repair that maintains the integrity of the wood.
Drying and Hardening
Wood Putty: Does not fully harden, which means it maintains flexibility. This makes it suitable for finished surfaces where movement may occur due to temperature changes.
Wood Filler: Dries quickly (often within minutes) and hardens completely, making it ideal for structural repairs. However, this rigidity can lead to cracking if used in areas subject to significant movement.
Application
Wood Putty: Best used on finished or stained surfaces for minor repairs, such as filling nail holes or covering small blemishes. It is not suitable for unfinished wood due to its chemical composition, which can damage exposed wood.
Wood Filler: Suitable for both finished and unfinished wood. It is often used for larger repairs, such as filling dents, gouges, and cracks in furniture or flooring.
Sandability and Staining
Wood Putty: Generally not sandable and does not accept stains well. Many types are pre-colored to match wood tones, eliminating the need for staining.
Wood Filler: Sandable once dry and can be stained or painted to match surrounding wood. This makes it versatile for achieving a seamless finish.
Outdoor Use
Wood Putty: More resilient for outdoor applications due to its flexibility, making it suitable for projects exposed to the elements.
Wood Filler: Not ideal for exterior use because it may shrink or crack with temperature changes.
When to Use Wood Putty & When to Use Wood Filler
Understanding when to use wood putty versus wood filler is crucial for achieving the best results in woodworking projects. Here’s a detailed guide based on the characteristics and applications of each material.
When to Use Wood Putty
Minor Surface Repairs: Wood putty is ideal for filling small cracks, nail holes, and surface imperfections on finished surfaces such as furniture and flooring. It is designed to blend in with the finish, making it perfect for cosmetic touch-ups.
Finished Wood Surfaces: Since wood putty contains chemicals that can damage raw wood, it should only be applied to surfaces that have been stained or varnished. This includes repairs on cabinets, trim, and other finished woodwork.
Outdoor Applications: Wood putty is suitable for outdoor projects where flexibility is needed due to temperature changes. It can expand and contract with the wood, making it effective for filling gaps in decking or exterior furniture.
Non-Sanding Applications: Typically, wood putty does not require sanding after application, which makes it convenient for quick fixes.
When to Use Wood Filler
Structural Repairs: Wood filler is best for more extensive repairs, such as filling larger gaps, gouges, and cracks in both unfinished and finished wood. It hardens completely, providing a durable repair that maintains the structural integrity of the wood.
Unfinished Surfaces: Unlike wood putty, wood filler can be used on raw or unfinished wood. It bonds directly with the wood fibers, making it suitable for repairs on new projects or surfaces that will be stained later.
Sanding and Staining: Once dried, wood filler can be sanded smooth and stained to match the surrounding wood. This makes it ideal for achieving a seamless finish on furniture or flooring.
Indoor Use: While some types of wood filler can be used outdoors, they are generally less suitable for exterior applications due to their tendency to shrink and crack with temperature changes. Therefore, it’s recommended primarily for indoor projects
| Feature | Wood Putty | Wood Filler |
| Best For | Minor surface repairs | Structural repairs |
| Suitable Surfaces | Finished wood only | Unfinished and finished wood |
| Flexibility | Remains pliable | Hardens completely |
| Sanding Required | Not typically sanded | Sandable after drying |
| Staining Capability | Limited (pre-colored) | Can be stained |
| Outdoor Use | Good for outdoor applications | Generally not recommended |
Summary Table
| Feature | Wood Putty | Wood Filler |
| Flexibility | Remains pliable | Hardens completely |
| Ease of Use | Premixed and easy to apply | Requires mixing (in some cases) |
| Color Matching | Available in various colors | Can be painted/stained |
| Moisture Resistance | Generally good | Varies by type; some are not water-resistant |
| Drying Time | Long | Quick |
| Sanding Capability | Not sandable | Sandable |
| Best For | Finished surfaces | Both finished and unfinished wood |
Both wood putty and wood filler are indispensable tools for wood repair, but their effectiveness depends on how and where you use them. By understanding their differences and applications, you can make confident decisions for your woodworking projects.
FAQs
1. Can wood filler be used outdoors?
Yes, but opt for a solvent-based filler for better moisture resistance.
2. Does wood putty harden over time?
Not completely; it remains slightly flexible to accommodate wood movement.
3. Can you paint over wood putty or filler?
Yes, but wood filler works better for painting and staining than putty.
4. Which is better for hardwood floors?
Wood filler is preferred for structural repairs, while putty is great for touch-ups.
5. How do I choose between oil-based and water-based products?
Oil-based options are durable and moisture-resistant, while water-based products are eco-friendly and easier to clean.
Also read: What Is Rubberwood ?
