Wood Filler vs. Wood Putty [What Should You Use]

When it comes to knowing about wood, are you a newbie or a know-it-all?

Do you often find yourself in doubt whether you should use a filler or a putty for repairing your precious wood projects? We see you, and we understand.

Well, seasoned woodworkers know that wood putty and wood fillers are two very different things. If you are among those few who know, then pat yourself on the back from our side. For those who have recently started their journey in woodcraft, we are going to resolve this common dilemma.

Wood putty and wood fillers are often confused, but we’ll differentiate between the two right from the basics in this informational guide. Fasten your seatbelts, you capable wood artisans; we’re in for a ride.

Starting from scratch, let’s discuss what these terms actually mean.

Wood Putty vs Wood Filler

Wood Putty

Wood putty is an oil-based filler substance used to cover up unwanted holes and slits in wood. Famously referred to as “wood plastic,” putty is primarily composed of boiled linseed oil and some proportions of wood dust, calcium carbonate, some diluent, and colorants. The components are known to vary from brand to brand, but this is the basic composition.

It is essential to know the ingredients or chemical composition of the compounds that we are going to use because it helps us assess their nature. Given the presence of calcium carbonate in wood putty, we should avoid using it on raw wood to prevent degradation.

It is majorly used in filling or repairing varnished and seasoned wood. Putty has a consistency similar to that of plastic resin but becomes clay-like with the addition of water. It has the texture of the dough, only a little bit stiffer. This stiff dough-like texture leads to the requirement of a putty knife for convenient application.

After application, it needs a lot of time to dry. Usually, wood putty dries on its own, but some types need an external hardening agent. Because of its availability in a variety of colors, you can select one that complements your wood stain.

When To Use Wood Putty

We already told you that wood putty should not be used on raw wooden pieces; it should only be applied after varnishing. Another interesting point worth noting is that putty can still contract and expand along with the wood even after it has stiffened, which makes it ideal for outdoor projects.

Wood tends to change in shape after being exposed to extended periods of heat and humidity. If we use wood fillers in outdoor wooden projects, they are more likely to break due to contraction and expansion. Therefore, putty is a viable option for outdoor use; instead of breaking, thanks to its elasticity it will change its shape accordingly.

Additionally, it is perfect for repairing minor imperfections or damages, like small nail holes, mismatched joints, etc. You can also use it for leveling an uneven surface and smoothing out rough edges or textures.

Why Use Wood Putty

There are many reasons to opt for wood putty for a project. Let’s discuss them briefly.

1. No Need For An Adhesive

Wood putty has adhesive properties. It doesn’t require the addition of any glue or sealer and can be used to repair cracks in leaking wooden structures like door frames or windows.

2. Easy To Apply

As we just discussed, the adhesive properties help it stick better to all surfaces, making it really convenient to apply. You can dab it over the smaller holes with your finger or use a putty knife. For larger cracks, a knife provides a better finish.

3. Lots Of Shades To Choose From

We understand that you’d want your repair work to blend in with the rest of the structure instead of drawing much attention to it. Putty is available in assorted shades and colors to match different types of timber and wood stains so that you can choose the one that camouflages with your project.

4. Cost-Effective

Wood putty is definitely very gentle on the wallet. Just one container is enough to last for multiple projects. It is durable and does not require frequent patching up. As a rule of thumb, store your putty container in a cool and dry place.

Wood Filler

Let us move on to the wood filler now. It is a  product used to carry out smooth surface repairs on the cracks and holes in the wood. Wood fillers consist of a binding agent and some filling substances. They are of multiple types based on the composition; we’ll briefly discuss them later.

These filters can patch up both small-grained and large-grained kinds of wood and are vital for porous wood like Walnut or Oak. Unlike putty, they are used to repair internally and help the wood maintain its integrity.

Wood fillers are used on natural woodwork projects prior to the lacquering. They aren’t high on looks or finish like putty, therefore need sanding out and painting. Once you’ve repaired the cracks and filled the holes, you can use sandpaper to tone it and apply a fresh coat of paint to give it some finishing.

As promised, we’ll now discuss the different types of wood fillers.

Types Of Wood Fillers

1. Latex-based Wood Fillers

Latex wood fillers are effortless to clean and can be used on a wide range of products. These fillers are most extensively used because of their water-based formula. Furthermore, they produce little to no odor and do not shrink or crack for a long time. Stainable and paintable by nature, you can even drill them if needed.

2. Epoxy Wood Fillers

Epoxy fillers provide protection to wooden structures that are exposed to humidity and are prone to rotting. This type works exceptionally well on unfinished projects. It repairs durably and doesn’t crack since it’s flexible. However, we’ll suggest using a sealer to keep the brittleness at bay. They are also the most cost-effective to use.

3. Polyurethane

The polyurethane fillers are used after mixing with sawdust, ideally from the same piece of furniture you’re going to repair. You just need to add a few drops of the mixture directly into the cracked areas and wait for it to dry. The repaired section will look like tough and clear resin. You can smoothen it out by sanding it after curing.

When To Use Wood Fillers

Wood fillers essentially contain organic compounds and therefore are safe to be used on untreated wood. They are brittle by nature and do not expand along with the wood; rather, they tend to dry out and shrink under direct heat. Hence, it is advisable to use them for indoor projects only.

Fillers are available mainly in neutral tones. If you want to use it in a particular shade, you’ll have to add some external tinting agents. In the absence of colorants, apply the filler in small patches and coat it with your wood stain until you are happy with the color. Maintain the filler-wood stain ratio for all the patches.

Why Use Wood Fillers

Wood fillers are versatile and robust fixing compounds. They are ideal for use because:

1. Quick To Dry

If you want your wooden piece to dry swiftly after the repair, then wood fillers are the perfect option. They dry within a few hours of use, and some brands are ready to go in just fifteen to twenty minutes. The curing period ranges from twelve hours to twenty-four.

2. Effortless Cleaning

Latex-based and acrylic fillers have a resin sheen and non-sticky texture because of which dust and other stains do not adhere to the surface. Therefore, they are straightforward to clean and can be wiped using a dry cloth.

Wood Putty vs. Wood Fillers

Hoping you’ve been paying attention, we can proudly say that now you know everything you need about putty and wall fillers, from their various types and uses to their advantages and disadvantages. This marks the end of the first part of our guide.

Moving further, we’ve now reached the big question, “What’s the difference between these two?” Let us discuss it in detail.

1. Application

We already know that both are used on timber; the difference lies in the timeline of use. Wood fillers do not have degrading compounds like carbonates, so they do not harm the raw wood on direct application.

On the other hand, the wood putty has a formula that can be destructive to the wood, and because of this reason, we need to protect our timber with a coat of varnish first. Once the wood has been seasoned, it is safe to be treated.

Wood putty is used to fix external cracks and holes, which are mainly on the surface of the timber. It is better in terms of looks and does not require much finishing. However, wood fillers are not that sleek and require a lot of sanding and painting. They are used to patch up structural holes that are finer and minuscule.

2. Material And Formula

Wood putty is a combination of some wood dust, a binder, and a thinner. The colored ones additionally contain some pigments. Lin-seed oil, lacquer, or water-base can function as binders in the formula. It is rightly said that “sawdust is a woodworker’s pixie dust” because some woodworkers can even make their own putty using fine dust and wood glue.

Coming to the composition of wood fillers, we’ll acknowledge that it’s not as trivial as a putty; it changes according to the different types. All of them contain some kind of bulking agent or solvent like latex, epoxy, clay, polyurethane, etc. Thanks to the solvent base, they are effortless to clean.

3. Drying Period

After adding water to the wood putty, it attains a dough-like consistency. For a clearer picture, you can imagine it to be like clay, just a little bit tighter. It takes a considerably long time to stiffen. You’ll have to leave it to dry for a couple of hours (more than twenty-four hours in some cases).

Wood fillers have a brittle appearance after curing. They have a resin-like appearance and a fast-drying formula. Once you have patched up your project, it’ll dry in under half an hour. After that, you just need to sand it perfectly and apply a coat or two of paint. This aftermath takes longer than the entire drying period of wood fillers.

4. Utility

Now, we’ll compare the uses of both of these filler compounds.

Wood putty has a high elasticity, which means it can retain its shape even after undergoing changes. Putties are ideal to use in outdoor wooden structures because of this retention. The furniture kept outside experiences expansion or contraction according to the changes in weather conditions. Wall putties stay elastic even after drying and do not break on twisting.

Wood fillers become brittle after drying. They cannot sustain changes like the former. Due to the rigidity, they should not be used for outdoor purposes. However, their brittleness does give them strength and durability. They last for a long time when used to repair indoor projects.

5. Cost

DIY projects are fun mainly because of three reasons. First, you get to add a creative touch to your possessions; second, you develop a hobby. And third, you save some money while doing it. To save on those extra bucks, you would naturally want to keep the cost to the minimum possible.

Wood putty is the most cost-effective option for any kind of repair work. On comparing the monetary input required for wood fillers against putty, we found that the latter came out to be on top. There aren’t significant differences in the prices, both are considerably cheaper than other methods, but still, wood putty outshines the fillers on this parameter.

6. Adhesive Properties

If your wood fixer has adhesive properties, you won’t have to spend money on a sealer or wood glue. Wood putty has a sticky formula and can behave as a great sealing agent, whereas wood fillers cannot. You’ll have to apply a layer of the sealer while using wood fillers.

Frequently Asked Questions

1. Can wood glue be substituted for wood fillers?

Yes, they can be. There are various options that can be used as a substitute for wood fillers. Hide glue, epoxy glue, and wood glue are a few such examples. However, these are makeshift options, and if you want your repair work to stay in place for a long time, we recommend using wood fillers instead of the other options.

2. Can we hammer in nails in the areas containing wood filler?

Wood fillers tend to become brittle after drying and therefore are prone to break if twisted rigorously. Some types can sustain being pierced by nails or screws, while some cannot. If your project requires extensive use of nails, then later wood filler will be ideal for you. It is a bit more flexible than the others and won’t crack.

3. What’s the curing and drying period for wood fillers?

Most wood fillers take about thirty minutes to dry, but just to be on the safer side, we’ll suggest waiting for about an hour. Do check the usage instructions on your package since the waiting time varies from one manufacturer to another.

Temperature and moisture play a deciding role in the waiting period. Fillers typically cure between twelve to twenty-four hours which is way faster than wood putty.

4. How can we make DIY wood filler?

Frequently, wood fillers are tough to find in the desired shade. Therefore, DIY wood fillers are a nice alternative and simple to make. For making filler, mix sawdust with lacquer or wood glue and form a paste.

The proportion and color of the sawdust will decide the shade, so you need to be very careful with that. You can also add an external coloring agent to your filler if you feel like it.

5. Is it safe to paint over all kinds of wood fillers?

No, all types of wood fillers are not necessarily suitable for painting. Although eighty percent of them can be sanded to perfection, only a few can be painted depending upon their composition. Check the product description on the container in advance to know better about the painting specifications.

6. Are wood fillers better than wood putty?

The answer to that depends on your requirements. If you want to repair an outdoor piece and don’t want to buy any additional glue or adhesive, putty is a better option. But if you want a fixer for indoor wooden structures and are running short on time, you should go for wood fillers.

It also depends on the type of wood you want to cover. Putty is better suited for unseasoned timber, while the filler is ideal for varnished wood. The color of your wood and the size of the cracks are also crucial for deciding what to use.

7. Will adding a filler to the joints of a structure add to its strength?

It is a common misconception that wood fillers help in making the structure strong. That is not the case. Fillers are just fixing material and have nothing to do with strength. However, if you are using a DIY one containing wood glue, it’ll definitely make the woodwork sturdier in that case.

Final Words

Woah! That was a lot of information to process, wasn’t it?

We started with what wood putty and wood fillers are, discussed them in-depth, and gradually moved toward their uses and benefits. Finally, we concluded with the striking differences between the two and answered some important questions.

To sum it up, we’ll say wood putty is the best for outdoor projects, and wood fillers are the best for indoor pieces. You know the drill now and will hopefully never confuse these filling materials with each other.

On that note, we’ll be signing off. See you next time!

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