When working with wood projects, you may come across situations where you need to fill gaps, cracks, or holes in the wood. Two common options for repairing wood are wood glue and wood filler. But how do you decide which one to use? Here’s a breakdown of when to choose wood glue vs wood filler.
Page Contents
What is Wood Glue?
Wood glue, also known as carpenter’s glue, is an adhesive made specifically for bonding wood. The most common type of wood glue is PVA (polyvinyl acetate) glue. PVA glues are very strong and create a permanent, rigid bond between wooden surfaces.
Here are some key features of wood glue:
- Creates a strong, permanent bond between wood surfaces
- Works by seeping into the pores of the wood and then hardening
- Offers high resistance to water once fully cured
- Ideal for bonding flat-to-flat wood joints like those in furniture
Popular brands of PVA wood glue include Titebond, Gorilla Glue, and Elmer’s. These glues are relatively inexpensive and easy to find at any hardware store.
Advantages of Using Wood Glue
Here are some of the main benefits of using wood glue:
- Strong bond: When used correctly, wood glue forms an incredibly strong, permanent bond between wooden pieces. The glued joint can be as strong as or stronger than the wood itself.
- Invisible repair: Wood glue dries transparent, allowing for an invisible seam between glued pieces. This gives a more seamless, natural wood appearance.
- Moisture resistant: Once fully cured, wood glue offers superior resistance to water, heat, and moisture.
- Affordable: PVA wood glues are very affordable, especially for the strength they provide.
- Easy to use: Wood glue is simple to apply. Just glue, clamp, and allow time to dry.
Wood glue is great for furniture repairs, woodworking projects, bonding dowels or joins, and any application where you need a durable bond between wood surfaces.
What is Wood Filler?
Wood filler, also called wood putty, is a material used to fill holes, cracks, and imperfections in wood before finishing. It’s an essential product for flawless wood repairs and projects.
Here are the main features of wood filler:
- Used to fill holes, gouges, cracks, and other voids in wood
- Dries solid after application for sanding and finishing
- Offers good adhesion and blending with the wood surface
- Typically dries faster than wood glue
- Available in different colors to match different wood shades
Common types of wood filler include:
- Solvent-based – Fast-drying oil-based putty
- Water-based – Acrylic or latex-based; low odor and nonflammable
- Epoxy – Extremely durable 2-part filler
- Colored plastic – Offers stainable filler for matching wood shades
Advantages of Wood Filler
Here are some benefits that make wood filler useful:
- Fills voids and flaws – Wood filler can patch holes, cracks, gouges and other imperfections for a smooth finish.
- Quick drying – Many types of wood filler dry solid in about 20-30 minutes for sanding and finishing.
- Stainable – Colored wood fillers allow staining to match the surrounding wood.
- Strong adhesion – Bonds well with wood for patching and filling voids.
- Sandable – Dries hard for easy sanding to a smooth, uniform surface.
- Affordable – Lower cost than replacing wood or using other fillers.
Wood filler allows for flawless wood repairs and undetectable filling of voids, holes, cracks, and defects in wood projects.
Wood Glue vs. Wood Filler: Key Differences
While both products are useful for repairing wood, there are some important differences between wood glue and wood filler:
| Wood Glue | Wood Filler |
|---|---|
| Creates strong, permanent bonds between wood surfaces | Fills gaps, holes and imperfections in wood |
| Won’t fill large voids or holes | Can be used to patch cracks, gouges, and flaws |
| Dries transparent | Comes in different wood tone colors |
| Longer drying time | Typically dries solid faster |
| Offers moisture resistance when cured | Sands easily when dry |
| Ideal for bonding wood joints | Useful for flawless repairs before finishing |
As you can see, wood glue bonds wood together, while wood filler patches imperfections in the wood itself. The drying time, staining ability, and main uses also differ between the two products.
When to Use Wood Glue
Here are the main situations where wood glue is the best choice:
- Bonding two flat pieces of wood together, like joints in furniture
- Laminating wood boards to make wider boards
- Assembling wood products like furniture, crafts, cutting boards, etc.
- Reinforcing mitered joints and butt joints
- Securing dowels, biscuits, and wood joinery features
- Gluing wooden veneers onto substrates
- Structural repairs of furniture, cabinetry, and other wood items
Anytime you need to create a permanent, water-resistant bond between two pieces of wood, wood glue is the way to go. The joint can ultimately be stronger than the wood itself.
Tips for Using Wood Glue
Follow these tips when gluing wood:
- Only apply glue to clean, smooth, dry wood surfaces
- Use just enough glue to fully coat the joint – too much glue is messy and wasteful
- Always clamp glued joints tightly until the glue cures
- Wipe away any excess glue squeeze-out immediately with a damp cloth
- Allow adequate drying time before handling glued pieces (24 hours is ideal)
- The tighter the wood joint fits before gluing, the stronger the bond will be
When to Use Wood Filler
Some common situations where wood filler is the right solution include:
- Filling cracks, gouges, holes, and imperfections in finished or unfinished wood
- Patching nail holes after removing nails from woodwork
- Concealing old screw holes in wood prior to restaining
- Repairing defects and flaws in wood furniture, cabinets, trim, and more
- Filling the open joints of wood panels prior to painting
- Smoothing scratches, grooves, dents, and defects in wood surfaces
- Patching knot holes, checks, splits, and surface defects in wood boards
Essentially, anytime you need to fill an imperfection in the wood itself before finishing, wood filler is ideal.
Tips for Using Wood Filler
These tips will lead to better results with wood filler:
- Choose a filler color that matches your wood’s tone
- Press filler firmly into holes and voids to prevent shrinking or cracking as it dries
- Allow adequate drying time as specified on the product label
- Always sand wood filler smoothly flush with the surrounding surface
- Prime and paint repaired areas for best concealment
- Consider an epoxy wood filler for repairs that will be frequently wet
- Clean and dry surfaces thoroughly before applying wood filler
Conclusion
Wood glue and wood filler both have important, yet distinct uses in woodworking and repairs. Now that you know the difference, benefits, and ideal uses for each product, you can choose the right solution for your next wood project.
Wood glue provides unbreakable bonds between wood boards and joints. Its high strength and water resistance make it integral for durable bonded wood projects. Meanwhile, wood filler offers easy patching of imperfections and flaws for flawless repairs and prep work. So reach for the wood glue when gluing joints, and use wood filler when you need to conceal defects in the wood itself.
With the ability to use both wood glue and wood filler in optimal situations, you can achieve professional-quality results on all your wood repairs and woodworking projects.