Wood Putty vs. Wood Filler: What’s the Difference?

Wood Putty vs. Wood Filler

Wood putty and filler are the two things that woodworkers and DIYers turn to when they need to fill out inconsistencies or repair minor defects in their wooden workpieces. While both do a great job finishing your wooden pieces, it is essential to know how they differ to understand what suits your projects best.

Overall Findings

Wood Putty

Wood Filler

  • Usually polyurethane, epoxy, or fiberglass
  • Oil-based & will remain flexible
  • Takes several hours to dry
  • Ideal for use on finished surfaces
  • Typically consists of  wood fibers/sawdust suspended in a binder
  • Can be either oil or water based
  • Dries in just 15 to 30 minutes
  • Used before staining & finishing

Wood Putty

  • Usually polyurethane, epoxy, or fiberglass
  • Oil-based & will remain flexible
  • Takes several hours to dry
  • Ideal for use on finished surfaces

Wood Filler

  • Typically consists of  wood fibers/sawdust suspended in a binder
  • Can be either oil or water based
  • Dries in just 15 to 30 minutes
  • Used before staining & finishing

Wood Putty vs. Wood Filler

1. Composition: Oil-based vs. Water-based

Ingredients for both wood putty and filler largely depend on the manufacturer. However, the main ingredients for most wood putty types are linseed oil, calcium carbonate, and a universal colorant.

All wood putties are oil-based and look more like a plastic resin and will feel like some soft clay when you add water to them. Since wood putty has a stiffer dough-like texture, you typically have to use a putty knife during application. It is easy to match the product to your wood’s stain with wood putty since it comes in various colors.

Wood fillers consist of wood fibers or sawdust suspended in a binder. While wood putty is typically oil-based, putty can sometimes be a water-based product depending on the ingredients and intended use. Also, wood fillers come in a neutral color, but you can often add a dry or tint to match your wood.

2. Application: Indoor vs. Outdoor Use

Wood filler is typically used on wood pieces and furniture meant for indoor use. While it is still possible to use it on outdoor furniture, it is never a good idea. Wood filler does not have the same flexibility as wood putty, meaning it will not expand and contract in response to the prevailing temperatures. Instead, wood filler often cracks when exposed to harsh weather.

Since wood putty holds up well in inclement weather, it is the preferred option for outdoor use. However, wood putty still works well for indoor use. It will also hold its structure well and offer more resistance to higher temperature and water, making it ideal for use in a wide variety of environments.

Another vital element to note when it comes to the application is that wood putty is ideal for finished surfaces as it can damage unfinished wood. On the other hand, wood filler is usable before staining and finishing.

3. Drying Time: Filler Always Dries Much Faster

Wood filler dries much faster than wood putty. When using it, the surface should be ready to sand in as little as 10 minutes. However, most will take between 15 and 30 minutes to dry, depending on the surface you are applying and the thickness.

For complete drying, you only have to wait for around 24 hours when using filler, unlike wood putty that can take several days and sometimes up to a week to cure completely. The longer cure time can be very inconvenient for some projects.

Wood putty also takes much longer to dry enough for sanding, as in many instances, you have to wait for several hours. You might have to wait up to 24 hours before you can sand the wood putty in some cases.

4. Versatility: Filler Comes In More Types for Increased Versatility

If you prefer something versatile you can use for different tasks, the wood filler is the better product for you of the two. You can get wood filler in various types that include latex, polyurethane, and epoxy. These different types are ideal for use on several types of finishes.

Wood putty does not offer as many type options as fillers and is hence more restrictive. However, it can still work well for all kinds of finishes. Better yet, it offers superior adhesive properties to ensure you can apply it without having to use a sealer as you would with wood fillers.

5. Cost: Wood Putty is More Cost Effective

While the cost for both wood putty and filler largely depends on things like the brand, type, and quantity, the former is generally more cost-effective.

Wood putty lasts much longer as you do not have to use a lot of it. What’s more, there is hardly any wastage with wood putty because even if it dries in the container or packet, a few drops of acetone for thinning it are all you need to bring it back to a usable condition.

With wood filler, you often need a little more of it than you do when using putty, and in case you have some leftover in the bottle, it will not be usable again once it hardens.

Conclusion

Wood putty and wood filler are two woodworking essentials for correcting imperfections on your workpiece. While they do similar jobs, wood filler is ideal for indoor use, while wood putty can work well for indoor and outdoor tasks. Additionally, wood filler is perfect for use before staining, and wood putty should only be used on finished surfaces.