Choosing The Right Wood Filler (Or Putty) For Your Project

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We’ve written quite a bit about wood fillers and putties, products that fill nail holes, cracks and holes in wood generally, and any opening in wood that needs to be filled.

Key Points:

  • What are you filling?  What kind of wood are you filling?  What finish will you use?
  • Different hole sizes call for different fillers.  Softwoods benefit from water-based fillers, while hardwoods can take any.  Water-based follows water-based, and oil-based follows oil-based when it comes to fillers and finishes.
  • Keep a variety of fillers handy in your shop inventory.

One such article is about staining wood fillers, and we think you will find it helpful as a companion piece to this article.  It is virtually inevitable that some part of your woodworking project will require a filling of some kind, and it’s good to have a number of different products in your shop inventory for just such a need.

There are many different types of wood fillers available, each with its own unique properties. The right wood filler for you will depend on the specific project you are working on, the type of wood you are working with, and the finish you plan to apply.

With so many to choose from and needs differing from project to project, it can be a daunting task to know the right filler for the right task.  Let’s see if we can make sense of all this and let you know how we approach the decision-making.

What Are The Common Considerations When Choosing a Wood Filler?

Minwax 42853000 Stainable Wood Filler, 16-Ounce

Each project is different, and so the needs for a filler differ, too.  We see the three key factors to consider as follows:

  • The size of the hole or gap you need to fill. For small holes or gaps, you can use a water-based wood filler. For larger holes or gaps, you may need to use a more durable filler, such as an epoxy or Bondo.
  • The type of wood you are working with. Some wood fillers are better suited for certain types of wood than others. For example, oil-based wood fillers are not recommended for use with softwoods, as they can cause the wood to swell.
  • The finish you plan to apply. Some wood fillers are more compatible with certain finishes than others. For example, water-based wood fillers are not recommended for use with oil-based finishes.

Once you have considered these factors, matching the right filler for the task is the next step in choosing your purchase.  Among the choices for fillers:

  • Water-based wood fillers. Water-based wood fillers are easy to use and dry quickly. They are a good choice for small holes and gaps in interior projects and are intended for unfinished wood.
  • Oil-based wood fillers. Oil-based wood fillers are more durable than water-based wood fillers. They are a good choice for large holes and gaps and for use with exterior projects.
  • Epoxy wood fillers. Epoxy wood fillers are the most durable type of wood filler. They are a good choice for repairing large holes and gaps and for use with exterior projects.
  • Bondo wood filler. Bondo wood filler is a two-part epoxy wood filler that is very durable. It is a good choice for repairing large holes and gaps and for use with exterior projects.
  • Wood putty. Putty differs from the others on this list as it does not harden and can not be sanded.  Yet, it has its place on the list of fillers to consider, and under the right conditions is itself an effective filler.  It is soft and pliable and very easy to use, and although it is not sandable, it can be smoothed to match the surrounding wooden surface.

Within each of these filler categories, there are many products to choose from, although we aren’t so much going to address brands as we will types of wood fillers to meet particular needs and uses.

The Three Main Factors In Choosing The Right Filler For Your Project

We’ve identified what we consider to be the three main factors in choosing the right wood filler for your project needs.  Careful consideration of each will lead to a good decision that will be based on the where and the what of your project.

The Size of The Hole or Gap To Be Filled

Small Holes and Gaps

Assuming the hole to be small, a nail hole, or a small dent, the easiest and quickest choice will be a water-based filler.  They are easy to apply and clean up after, and they are less likely to yellow over time. They tend to be crumbly in consistency, but because they are water-based (with additives, including a binder and real wood fiber), they can be smoothed with a little water.

They clean up easily, again, because they are water-based and dry quickly. Some brands will dry in as little as 10 minutes and can be sanded in as little as 20 minutes.

Oil-based fillers are more durable than water-based fillers, and they dry faster. However, they can be more difficult to clean up, and they can yellow over time. They have an inherently smoother consistency than water-based and do not need anything to become more so. They will be of more protection to wood against moisture and humidity, again because they are petroleum-based.

They are also more toxic than water-based fillers and much higher in VOCs (volatile organic compounds) that emit as gas as the filler dries and cures.  A respirator is necessary when working with oil-based fillers, and the room you are working in should be well-ventilated. 

These fillers should be used on unfinished wood and for indoor projects.  Each dries hard and can be sanded to a smooth finish before finishing the wood.  Some fillers take staining well, and in fact, there are stainable wood fillers such as MinWax Stainable Wood Filler to choose from.  There are also tinted fillers, although there are limited colors to choose from; matching a tinted filler to the stain you wish to use for your project may not be possible.  

Minwax 42853000 Stainable Wood Filler, 16 oz, Natural, 16 Ounce
  • STAINABLE WOOD FILLER – Minwax Indoor/Outdoor Wood Filler is a stainable and paintable latex…
  • REPAIR CRACKS – The durable wood filler is ideal for repairing cracks, small gouges, nail holes,…
  • APPLICATION STEPS – Squeeze a liberal amount of into the area to be filled and press firmly into…

In such instances, you could mix a drop or two of the stain with the filler to tint it yourself.  When doing so, be sure to use a water-based stain with a water-based filler and an oil-based stain with an oil-based filler.

Wood putty: Wood putty is a less durable option, but it is easy to use and can fill large holes. It is available in a variety of colors to match different types of wood.

Wood putty is typically available in a variety of colors to match different types of wood. It is applied with a putty knife and can be sanded smooth once it has dried.

Wood putty is a good choice for filling small holes and imperfections in finished wood. It is not as durable as some other types of wood fillers, such as epoxy or Bondo, but it is easy to use and relatively inexpensive.

It is not a good choice for unfinished wood, though. It does not harden and can not be sanded. Woodworkers who prefer to use putty rather than a filler will stain the wood first and then match a putty color to the stain they chose so it will blend in easily.

Larger Holes and Gaps

For larger holes, cracks, and gaps, something more durable will be needed, something like an epoxy or Bondo filler.

The best wood filler for a large hole is one that is durable, easy to use and matches the color of the wood. Some good options for large holes include:

Epoxy wood filler: Epoxy wood fillers are very durable and can fill large holes. They are available in a variety of colors to match different types of wood and are relatively easy to use.

Epoxy fillers are composed of resin and a hardener. These two parts are mixed together to create a strong, durable filler that can be used to repair large holes and gaps in wood. Epoxy wood filler is available in a variety of colors to match different types of wood.

Here are some of the benefits of using epoxy wood filler:

  • Durable: Epoxy wood filler is very durable and can withstand the elements.
  • Easy to use: Epoxy wood filler is easy to mix and apply.
  • Available in a variety of colors: Epoxy wood filler is available in a variety of colors to match different types of wood.
  • Non-shrinking: Epoxy wood filler does not shrink, so you can be sure that your repair will be permanent.
  • Water-resistant: Epoxy wood filler is water-resistant, so it can be used on exterior projects.

Bondo wood filler: Bondo wood filler is another durable option that can fill large holes. It is available in a variety of colors to match different types of wood.

3M Bondo All-Purpose Putty, Designed for Interior and Exterior Home Use,…
  • Two-part filler bonds to broad range of surfaces for permanent, non-shrink repairs
  • Cures fast; sandable in 15 minutes for fast same-day repairs
  • Light gray when mixed, helping blend with surfaces for consistent appearance

Bondo wood filler, a product of 3M, is also a two-part epoxy wood filler that is very durable. It is a good choice for repairing large holes and gaps and for use with exterior projects. 

To use Bondo wood filler, simply mix the two parts together according to the instructions on the package. Apply the filler to the hole or gap with a putty knife, and smooth it out with your fingers. Once the filler has dried, sand it smooth with fine-grit sandpaper. If you are staining the wood, be sure to sand the filler lightly before staining.

Bondo Rotted Wood Restorer is another 3M product that is often used along with Bondo Wood Filler. The Restorer will help fill and reshape damaged wood and is followed in use by the wood filler that leads to a smooth finish after sanding.  Bondo Wood Filler is a quick repair that will dry for sanding in 15 minutes and be painted or stained in 25 minutes.

Here are some of the benefits of using Bondo wood filler:

  • Durable: Bondo wood filler is very durable and can withstand outdoor elements.
  • Easy to use: Bondo wood filler is easy to mix and apply. Directions on the label are easy to follow
  • Available in a variety of colors: Bondo wood filler is available in a variety of colors to match different types of wood.
  • Non-shrinking: Bondo wood filler does not shrink, so you can be sure that your repair will be permanent.
  • Water-resistant: Bondo wood filler is water-resistant, so it can be used on exterior projects.

Plastic Wood: Plastic wood is a composite material that is made from wood fibers and plastic resins. It is used to repair and replace wood in a variety of applications. Plastic wood is available in a variety of forms, including putty, sticks, and sheets. It can be used to fill holes, make repairs, and create new objects.

Plastic wood is a durable and versatile material that is easy to use. It can be sanded, stained, and painted to match the surrounding wood.

Plastic wood is also weather-resistant and can be used for outdoor projects.  The most well-known plastic wood is DAP, a solvent-based wood filler.  It dries hard and is sandable, paintable, and stainable, all with water-based finishes.

Dap 21506 Plastic Wood Filler, 16-Ounce
  • Adhesives & Sealants
  • Country of manufacture: United States
  • Manufacturer: Dap

The benefits of using plastic wood include:

  • Durable: Plastic wood is a durable material that can withstand the elements.
  • Versatile: Plastic wood can be used for a variety of projects, including repairs, filling holes, and creating new objects.
  • Easy to use: Plastic wood is easy to sand, stain, and paint.
  • Weather-resistant: Plastic wood is weather-resistant and can be used for outdoor projects.

When choosing a wood filler for a large hole, it is important to consider the size of the hole, the type of wood, and the finish that will be applied. It is also important to follow the instructions on the package carefully.

Here are some additional tips for filling large holes with wood filler:

  • Clean the area around the hole. Remove any dirt, dust, or debris from the area around the hole. This will help the wood filler to adhere to the wood.  Use a product like Bondo Rotted Wood Restorer if necessary, also after removing any decayed or rotten wood from the area.
  • Apply the wood filler in thin layers. Applying the wood filler in thin layers will help it to dry more evenly and more quickly.  Still, follow the suggested dry times on the label of the product you are using.
  • Sand the wood filler smooth. Once the wood filler has dried, sand it smooth with fine-grit sandpaper.
  • Apply a finish to the wood. Once the wood filler has been sanded smooth, apply a finish to the wood. This will help to protect the wood filler and make it look more natural.

The Type of Wood You Are Using 

The type of wood you are using in your project will factor into your decision, also.  If you are using a softwood like pine, for instance, you would not want to use an oil-based filler, as it could cause the wood to swell.  However, that would not be the case with a hardwood like oak or walnut.

A water-based filler could be used on both softwoods and hardwoods and can be considered a general all-purpose filler for small holes and gaps.

The Finish You Plan To Apply

The third consideration when choosing a wood filler is the finish you will be using on your project.  We’ve already mentioned that a water-based filler should be used when the stain you have chosen is a water-based stain; and an oil-based filler should be used when you have chosen an oil-based stain.

The same holds true when you have chosen paint – water-based with water-based, and oil-based with oil-based.

Our Go-To Wood Filler

Mohawk Finishing Products Fill Stick (Fil-Stik) Putty Sticks (White)

There are many wood filler products to choose from by brand, and as you’ve just finished reading, they come in a variety of types: water-based, oil and solvent-based filler, plastic and epoxy, putty, and even tinted wax fillers like Mohawk Fil-Stiks.

We are partial to GoodFilla, though, a water-based wood and grain filler, and it is our go-to filler in most instances.  It is easy to apply and can be coated by any finish.

It spreads easily and evenly into wood grain and dries in as little as 15 minutes.  It has great adhesion to the wood and cleans easily with water. It’s a versatile wood filler, and you won’t be sorry to have a container of Goodfilla in your shop.  

Water-Based Wood & Grain Filler – Base/Neutral – 8 oz By Goodfilla | Repairs,…
  • ⚒️ HIGH QUALITY & MONEY SAVING: Save time and money with this wood filler that does not shrink,…
  • ⚒️ DESIGNED FOR PROFESSIONAL WOODWORKERS: This is the most innovative, easy-to-use, water-based…
  • ⚒️ HARDY & CONSISTENT: As any woodworker will tell you, they throw hardened wood filler out all…

MinWax is another brand we like, and it makes a stainable wood filler, as well as premixed putty.  If the wood you are using a filler on is already stained, its premixed matching color putty can be a good choice for your project.

Finished or unfinished woods, small and large holes and cracks, softwoods and hardwoods, water-based and oil-based finishes – – these will all influence your choice of filler to use.

Follow our recommendations, and the choice will become easy.  Keep a variety of fillers handy in your shop, and you will be ready to fill any holes and cracks in wood to keep your project moving along to completion.

Last update on 2024-04-19 / Affiliate links / Images from Amazon Product Advertising API

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