Wood Putty vs Wood Filler: How To Choose?

wood putty vs wood filler

You may have heard the terms “putty” and “filler” used interchangeably, but they are not the same thing. It’s important to understand the fundamental differences between the two before you start using them, to make sure you’re getting the best performance. Read on to learn what separates these two compounds and when it’s best to use them.

Wood Filler

Wood filler typically contains wood particles, fibers, or cellulose mixed into the compound. It sometimes even contains limestone and other minerals you would typically find in drywall for added durability. It hardens as it dries. You can sand it and stain it, and it’s best for use on unfinished wood.

wood filler

Pros
  • Firmer compound
  • Can be sanded and stained
  • Best for unfinished wood
Cons
  • May crack if exposed to extreme weather
  • Not great for outdoor use

Wood Putty

Wood putty is typically made of plastics such as polyurethane or epoxy mixed in an oil-based compound. Unlike wood filler, you can’t sand putty. It also doesn’t harden like filler, which means you can’t stain it. Fortunately, you can buy it in different wood tones to match your project. Use it on finished and stained wood.

wood putty

Pros
  • More pliable compound
  • Comes in varying wood tones
  • Best for finished or stained wood
  • Great for filling nail holes
  • Can be used outdoors
Cons
  • Can’t be sanded
  • Doesn’t harden as well as filler
  • Not stainable or paintable

Two-Part Filler

This epoxy-based filler will give you the best of both filler and putty functionality. Mix it first, until it’s the consistency of cookie dough. Then mold it to the wood and wait for it to harden before sanding, drilling, carving, or painting.

Pros
  • Middle ground between putty and filler
  • Moldable
  • Can be sanded and drilled
  • Paintable and stainable
  • Works indoors or outdoors
Cons
  • Must be mixed before using

What to Use for Exterior Patching

Putty is best for exterior use. Though it doesn’t harden the same way as filler, it can expand and contract enough to withstand temperature changes. Finish the wood before applying it, however, since it won’t be paintable or stainable. It works great for furniture, too. But for larger outdoor projects and refurbishment, a two-part filler is your best bet. It will give you the flexibility you need to sand, paint, and complete other finish work.

What to Use for Interior Patching

Wood filler works best for interior work. It hardens better, you can sand, stain, or paint it, and you don’t need to worry about extreme temperature changes making it expand or contract. It’s also more durable than putty, since it contains fibers and minerals to reinforce it. Again, two-part filler will be better for larger projects, since it’ll give you the flexibility to complete detailed finish work like sanding and painting.

Conclusion

While putty and filler are often described interchangeably, you can see how different the two compounds are. It’s important to determine where you’ll be patching the wood and to what kind of temperatures it will be exposed before you choose which one to apply. If you want the best of both worlds, however, a two-part epoxy filler may be best. Good luck with your project!

Related:
Wood Shaper vs Router: Which One to Choose?


Header image credit: Rlsheehan, Wikimedia

About the Author Ryan Doskocil

Ryan is a freelance writer from Arizona. When he's not blogging about his favorite hobbies, he's writing fiction, hiking or running in the great outdoors, and spending time with family.