When working with wood, you may need to fill holes or fix imperfections. Wood filler and wood putty are two common products used for these tasks. While they serve a similar purpose, they have significant differences. Understanding these differences will help you choose the right one for your project, ensuring a successful repair or finishing job.
Nails, damage, or natural imperfections can cause holes in wood. Whether repairing furniture, installing timber flooring, or working on a DIY project, you may need to fill these gaps. But should you use wood filler or wood putty? Let’s take a closer look.
Let’s get straight to the point.
Wood filler and wood putty fill gaps in wood but are used in different situations. Wood filler is water-based, dries hard, can be sanded, and is best for indoor projects on unfinished wood. It dries quickly and can be stained or painted over. Wood putty is oil-based, flexible, and ideal for outdoor use or fixing imperfections in finished wood. It resists cracking due to weather changes but cannot be stained. Choose filler for raw wood repairs and putty for outdoor or finished wood fixes.
Wood Putty: Flexible And Oil-Based
Wood putty is a versatile and flexible product, often described as having the texture of window glazing or plumber’s putty. Since it is oil-based, wood putty is highly resistant to moisture and temperature changes. This makes it ideal for outdoor use, as it won’t crack or wash away when the wood expands or contracts due to weather.
Wood putty is often used on finished wood to repair minor imperfections. It’s available in different colours to match various wood types. However, it cannot be stained, which is important when choosing it for a project.
If you plan to paint over wood putty, use oil-based paint, as water-based paints will not adhere well to an oil-based product. A small amount of wood putty goes a long way, and once applied, it should be allowed to dry for a few days before sanding or painting.
How To Use Wood Putty?
Wood putty is often called plastic wood because it is widely used to fill holes and defects in finished wood. However, it’s not suitable for all situations.
Application
Wood putty should be applied after the wood has been stained or varnished. It is not recommended for use on raw wood due to the potential for toxins in the formula. Its clay-like texture makes it difficult to sand, so it’s typically applied with a putty knife to smooth small imperfections.
While some putties advertise quick drying times, they often take longer to cure properly. Depending on the brand, you may need chemical hardeners to ensure the putty sets correctly.
Colour Considerations
Wood putty can change colour as it dries, with lighter shades often becoming darker over time. Always choose a lighter colour to avoid a mismatch and allow the putty to dry before making further adjustments.
Varieties
Many types of wood putty are on the market, with options in various colours and formulas. Most wood putties are oil-based, often using linseed oil as a key ingredient. This oil helps create a durable product ideal for outdoor use.
Why Choose Wood Putty?
Wood putty offers different benefits that may make it a better fit for your project:
- Moisture resistant: Wood putty is oil-based, so it’s perfect for use in outdoor environments where wood will be exposed to the elements.
- Flexible: Unlike wood filler, wood putty remains flexible and won’t crack as the wood expands and contracts.
- Easy to apply: Wood putty can be applied with a putty knife or even your fingers for smaller areas, making it a versatile option for minor repairs.
Wood Filler: Water-Based And Sandable
Unlike wood putty, wood filler is typically water-based and can be sanded. Wood filler is primarily used on unfinished wood, making it ideal for indoor furniture and projects that will be stained or painted after the filler is applied.
Epoxy wood fillers are another option and are often used for raw and prefinished wood. These two-part products combine the durability of wood filler with the flexibility of putty, making them an excellent choice for heavy-duty repairs.
Wood fillers dry to a hard finish, which can then be sanded smooth, ensuring a seamless finish before applying paint or varnish.
How To Use Wood Filler?
Unlike wood putty, wood filler is used on unfinished wood. It is applied before the final coat of stain or paint and can be sanded smooth once dry. Wood filler is easy to mould and spread, making it simple to work with, especially for large cracks or gaps in wood.
Fast Drying
One of the main benefits of wood filler is its quick drying time. Some fillers can dry for at least five minutes, while others take under 24 hours. Fast-drying fillers are ideal when you’re working on a tight deadline.
Colour Matching
Wood filler doesn’t add much colour to wood, so stain it to match the surrounding material. To achieve a natural look, mix the wood filler with sawdust from the wood you’re working with.
Ingredients
Wood filler is made from various materials, including epoxy, latex, and clay. Latex fillers are particularly popular because they easily clean up and work well with dyes. However, epoxy fillers provide extra strength, although they require additional sanding.
Why Choose Wood Filler?
There are several reasons why wood filler might be the right choice for your project:
- Quick drying: Wood filler dries fast, often within minutes, which can be a huge time-saver on urgent projects.
- Ideal for large holes: Wood filler fills gaps and cracks in unfinished wood.
- Easy to work with Once dry, wood filler can be sanded to a smooth finish, making it a great option for projects that need to look flawless.
The Best Uses For Wood Filler And Putty
While both products can fill gaps and imperfections in wood, there are some clear distinctions in their applications.
Indoor Use: Wood Filler
Wood filler is most effective for indoor projects. Its sandable nature and compatibility with stains make it the go-to choice for unfinished wood. After the filler is applied, sanded, and painted, it creates a smooth, flawless surface.
However, it’s important to remember that wood filler is not flexible. It can crack on surfaces that expand and contract with temperature changes, like outdoor furniture or exterior woodwork. Wood filler shrinks when exposed to sunlight, so it’s not the best option for outdoor applications.
Outdoor Use: Wood Putty
In contrast, wood putty is ideal for outdoor use. Its oil-based formula remains flexible, allowing it to move with the wood as it expands and contracts in different weather conditions. Wood putty won’t crack or shrink when exposed to the elements, making it perfect for external repairs.
Some carpenters even use two-part auto body filler, a fibreglass-based putty, for extra durability in outdoor applications. Once primed and painted, these materials can be a long-lasting solution for exterior woodwork.
When To Avoid Wood Filler Or Wood Putty?
- Wood filler is unsuitable for outdoor applications, as it cannot expand and contract with the wood. Using wood filler outside can lead to cracks over time.
- On the other hand, wood putty should not be used on raw wood. It can damage the wood, and the chemicals in putty may prevent proper staining or finishing later on.
Conclusion
Both wood filler and wood putty have their place in woodworking, but they serve different purposes. Use wood filler for indoor projects that require a smooth, stainable finish. Wood putty is ideal for outdoor repairs or filling small imperfections in finished wood. By understanding the differences between these products, you can ensure the best possible outcome for your woodworking projects.
FAQs About Wood Fillers
What Is The Difference Between Wood Filler And Wood Putty?
While the chemical formula of wood putty can damage exposed wood, wood filler is made to bind directly to the natural wood and doesn’t need stain before application. Patch holes inside the home with this quick-drying, paintable, stainable, sandable wood and grain filler.
How Thick Can Wood Filler Be Applied?
Try not to go thicker than half an inch. A 1/2 in deep and 3/8 wide would be good. But you can go as long as you wish.
How Long Does It Take For Wood Filler To Dry?
Most wood fillers dry quickly, achieving full hardness in about 30 minutes to one hour. After this drying window, you can send the product to flush with the rest of the wood surface. Then, you can paint or apply wood stains over it to finish the project without waiting longer.
Is Wood Filler Strong Enough To Screw Into?
Yes, the wood filler can hold a screw. Once the wood filler is cured well, you can screw it with a small pilot hole. Wood filler cannot hold load or stress. It can only hold small screws that carry a very small amount of load or stress.
What’s The Difference Between Sealant And Filler?
The main difference between the two is the longevity of the intervention applied. A sealant is expected to last no more than a year, while fillings can last up to ten years. The sealant is preventive, while the filling is a form of damage repair.
