Ever wondered why your wood putty stays soft while wood filler hardens? Join us as we explore this fascinating world of woodworking mysteries!

Both wood putty and wood filler do useful tasks repairing damages and filling holes that occur on a regular woodworking basis.
Even though the task of both wood filler and wood putty is the same, they are totally different from each other in many factors. Especially in composition.
As a woodworker, when I was using wood putty for outdoor woodworking projects, I was always curious about its hardening ability.
I did some research and here is what I’ve found: Does Wood Putty Harden?
No, Wood Putty does not harden since they’re designed to stay pliable for adaptability and easy adjustments. Unlike water-based wood fillers that dry and harden, this type of putty is often used for projects that require ongoing flexibility, such as window frames or door installations.
But that’s just a quick snapshot.

So, in this article, I’ll deeply discuss why does wood putty does not harden, how to make wood putty harden, how long does it take, how to make wood putty dry faster based on oil-based wood putty and water-based one as well.
So let’s keep going!

Why Does Wood Putty Not Harden?
Wood putty does not harden because it can change its dimensions according to the environmental humidity and temperature levels due to its unique composition and flexibility.
Wood putty dries but mostly does not harden.
It stays the same position as it is even the wood gets twisted. This is where wood putty and wood filler behave separately from each other.
The main use of wood putty is to patch small holes in finished wood like covering nail holes, joint mismatches, small blemishes.
Now let’s talk about what are the reasons for this non-hardening behaviour of wood putty in detail.
Reasons Why Wood Putty Might Not Harden
Incorrect Mixing
Most wood putties come as a two-part system, with a putty and a hardener.
If you didn’t mix these two parts together correctly or in the right proportions, the putty might not harden.
Imagine making a cake but not putting in enough baking powder. It won’t rise properly, right? The same concept applies here.
The hardener is the key ingredient that triggers the putty to solidify, so not using enough can lead to a putty that stays soft.
Old or Expired Putty
Another possibility is that the putty is old or expired. Just like how paint can dry out and become unusable, putty can also lose its effectiveness over time.
If the putty has been sitting on a shelf for a long time, it might not harden as it should, regardless of how well you’ve mixed it.
Improper Storage
If the putty hasn’t been stored properly, it might not harden.
If the lid wasn’t secured tightly, for instance, the putty might have dried out partially or gotten contaminated with dust or moisture.
This can affect its ability to harden when applied.
High Humidity
The environment can also play a role.
If it’s particularly humid, the excess moisture in the air might be preventing the putty from drying out and hardening properly.
Practical Tips and Tricks
Now that we know what might be causing the problem, let’s talk about what we can do about it.
- Proper Mixing: Always make sure to follow the manufacturer’s instructions for mixing putty and hardener. Use the correct proportions and mix thoroughly.
- Fresh Putty: If the putty is old or expired, it might be best to buy a new one. Check the expiry date before purchasing.
- Store Correctly: Store the putty in a cool, dry place and always make sure the lid is tightly secured after use.
- Check Your Environment: If it’s very humid, consider using a dehumidifier or waiting for a less humid day.
With all these features, what makes wood putty different from wood filler. Don’t worry! That’s what I’m going to tell you next.

Wood Putty vs Wood Filler: What’s the Difference?
Ah, the age-old question that has puzzled many a DIYer and woodworking enthusiast: wood putty vs wood filler.
Are they the same thing? Are they different? How do you know which one to use for your project?
Let’s dive in and unravel this mystery together.
Understanding Wood Putty
First, let’s get reacquainted with wood putty, a material we’ve discussed earlier.
Remember, wood putty is a material used to fill imperfections like nail holes, scratches, or dents in wood.
But let’s delve deeper into its composition and characteristics.
Wood putty, also known as plastic wood, is a plasticized material often made of wood dust and a binder that can either be water or oil-based.
It typically remains flexible even after drying, which makes it ideal for use in areas subject to movement or changing conditions.
Think of it this way: Have you ever had a door or window frame that kept sticking or expanding with the weather?
Wood putty would be perfect for that! It’s best applied after the wood project has been stained or varnished because it’s available in different colors to match various wood types and finishes.
Getting to Know Wood Filler
Now, let’s shift gears and talk about wood filler. Similar to wood putty, wood filler is used to cover up imperfections in wood.
However, wood filler, often made of wood dust and a binder like epoxy, tends to harden and becomes an integral part of the wood piece after drying.
Wood filler is more like that reliable friend who’s always there to help you out.
Got a deep gouge or a major defect in your wood piece? Wood filler is your go-to solution.
It’s strong and sturdy and, once hardened, can be sanded, drilled, or even nailed into, just like the rest of your wood piece.
Also, it’s generally applied before the staining or painting process.
Wood Putty vs Wood Filler: When to Use Which
Wood Putty
As we’ve discovered, wood putty is great for fixing minor cosmetic imperfections, especially on finished wood projects.
You know those small nail holes or minor scratches on your stained hardwood floor?
Wood putty would be perfect for fixing those! Just make sure to pick a color that matches your floor’s finish.
Wood Filler
Wood filler, on the other hand, is ideal for more significant repairs, like deep gouges, cracks, or rot in unfinished wood.
Imagine you’ve got an old chair that you’re trying to refurbish, and there’s a big crack in the seat.
That’s where wood filler comes in! You can fill the crack, let it harden, sand it smooth, and then stain or paint the chair to your liking.

Benefits of Wood Putty Non-Hardening Behavior
Wood fillers harden after some time once it is applied but wood putty does not.
Wood fillers do not change their dimensions according to environmental changes while wood putty does.
In outdoor conditions, the wood tends to expand when there is high humidity and contract in low humidity.
This movement cannot be changed. It is a natural process.
The problem is if we apply wood filler for our outdoor woodworking projects, fillers cannot move or change dimensions along with wood according to the humidity and temperature levels because of less flexibility.
When the wood is expanding and contacting the wood filler will remain the same and eventually, you’ll notice cracks and scratches in the area wood filler have applied. But wood putty acts completely different.
Because of being a non-hardening and flexible paste, wood putty can move or change dimensions along with wood according to the humidity and temperature levels.
This won’t give any cracks or breaks as wood fillers do.
So, let’s talk about the drying process of wood putty which only happens without hardening.
How Long Does Wood Putty Take to Dry?
Usually, wood putty completely dries within 2-8 hours. But the dry time of wood putty depends completely on you.
If you apply less amount of wood putty, it’ll dry faster than the time that taken when the application of high amount.
Also, the drying time can differ according to the type of wood putty you going to use. There are different drying times and drying mechanisms for water-based wood putty and oil-based ones.
Oil base Wood Putty Dry Time
Oil-based wood putty dry time is about 48 hours. Oil-based wood putty is great if you want the top coat to be oil-based.
Once you did the finishing of your woodwork, apply the oil base wood putty and wait around 5 to 20 minutes to haze it over.
The drying time of wood putty can vary according to the temperature and humidity levels.
However, as soon as the stain is dried, remove the excess with a cloth and leave the wood putty to cure around 12 hours.
After that check the surface again and you can reapply the wood putty onto the same area if you’re not satisfied with how it looks.
When you feel “ok” about how it looks, leave it for another 48 hours until it is fully dried.
Water-based Wood Putty Dry Time
Water-based wood putty dry time is about 24 hours. Oil-based wood putty is great if you want the topcoat to be water-based.
Like an oil-based one, once you have done the finishing of your woodwork, apply the water-based wood putty. But here you don’t need to wait minutes until it hazes over.
You should wipe the surface to remove the excess stain as soon as the stain is dried.
Then let the wood putty dry for an hour and sand with 320 grit sandpaper to check whether the wood putty is completely dried or not. If it’s not, the sandpaper will gum up.
However, I highly recommend keeping the wood at least 24 hours to complete the drying process fully.

How Can You Make Wood Putty Dry Faster?
As you can notice the drying time of wood putty is too much with our busy schedules.
So, there are several methods I personally follow and recommend making wood putty dry faster.
They are,
- Always go for thin layers
- Warm up the area
- Keep the area clean
- Apply hardeners
- Do proper sanding
So, let’s discuss wood putty fast-drying methods in detail.
1. Always Go for Thin Layers
Never apply thick layers if you want to make wood putty dry faster.
Thick layers take a huge amount of time to dry because there is a lot inside that is completely covered from the outside environment.
By applying thin layers of wood putty, you’ll be able to uncover most of the wood putty to the outside environment and make the dry faster.
But you need to make sure that the layer is not too much thin. Because the layer is too thin it cannot cover up the cracks and scratches well and wood putty does not harden easily as we wish.
Always give the priority to the operation that needs to be completed then its drying time. Otherwise, the whole thing will be just a waste of time and money.
Thin layers dry faster. After the application of your first layer, let it dry, and then apply the second or third layers until the cracks and scratches are fully covered.
While applying each layer you need to make sure the rule of thumb is “Never go for thick layers”.
2. Warm Up the Area
Heat will soften the wood putty. Wood putty in the drying process will increase when it is soft.
So, I highly recommend applying wood putty in the daytime under the sunlight. The heat that came from the sun increases the drying time of wood putty.
If you live in a place where that doesn’t reach sunlight much, do the application in the daytime or do the application of wood putty to the areas where cracks display during summer.
This increases the effectiveness of the process and increases the drying time significantly.
3. Keep the Area Clean
Impurities can increase the drying time more than you expect. So, always clean the area/surface before applying the wood putty layer.
If you do the application of wood putty without cleaning, you’ll end up with a dumpy surface, and can take days to complete the drying process.
You can remove dirt and debris before applying each layer of wood putty by wiping them off using a damp cloth.
This will decrease the drying time significantly.
4. Apply Hardeners
By adding hardeners to the wood putty, you can make the wood putty dry faster. But you need to have proper guidance on that.
Because if add excess hardeners to the wood putty, you’ll end up with nothing and this can harden your wood putty quickly.
Epoxy resin is the best hardener that I can recommend to mix with wood putty before applying it to the wood that can make the putty dry faster.
But again I do not recommend this method if you’re a beginner in woodworking.
5. Do Proper Sanding
Sanding can smooth the surface and remove the dumps at the same time. by sanding before applying each layer of wood putty the drying time will significantly decrease.
Also, you can check whether the putty is completely dried or not by sanding it with 320 grit sandpaper.
As you can see, even though wood putty does not harden, you need to focus more on its drying process.
Does the wood putty harden question always comes from people who switched recently from wood fillers to wood putty because wood fillers do harden over time, not like wood putty.
Both wood putty and wood fillers are able to screw, nail, stain and paint when they’re fully dried.
Read to know, Can You Paint Over Wood Putty?

What is Non-Hardening Wood Putty Used For?
Non-hardening wood putty, also known as oil-based putty, is an unsung hero of the woodworking world.
While it may not be as well-known or commonly used as its hardening counterpart, it has some unique and impressive abilities of its own.
Let’s delve into the many uses of non-hardening wood putty and why it may become a new staple in your toolbox.
Here’re the uses of non-hardening wood putty,
Filling and Sealing
The primary use of non-hardening wood putty is to fill and seal minor gaps and cracks in wood.
For example, if you’ve ever installed a window or door, you know that tiny gaps can sometimes appear between the frame and the wall.
In such instances, non-hardening wood putty is your trusty sidekick.
You can use it to fill these gaps, creating a more professional and finished appearance while also preventing drafts and heat loss.
Flexibility Under Changing Conditions
One of the significant benefits of non-hardening wood putty is its flexibility.
This feature makes it ideal for use in areas of your home that may experience changing conditions, such as shifts in temperature and humidity.
For instance, if you live in a place with distinct seasons, you’ve probably noticed your wooden doors or windows sticking in the summer and contracting in the winter.
Non-hardening wood putty, used in the joints or seams, can adapt to these changes, preventing cracking or splitting that may occur with harder materials.
Cosmetic Improvements
Non-hardening wood putty is also excellent for making minor cosmetic improvements to finished wood items.
Say you have a beautiful antique wooden chair, but there’s an unsightly scratch on the armrest.
No problem! You can use non-hardening putty to fill the scratch.
Since the putty remains pliable, it won’t crack or pop out if the wood contracts or expands over time.
Congrats folks! Now you know all about does wood putty harden and how it differ from wood filler.
Let’s answer some frequently asked questions.
FAQs
Why does my wood putty not harden?
Wood putty might not harden if it’s an oil-based, non-hardening type, designed to remain pliable for easy adjustments and to cope with changing weather conditions.
Is it bad if wood putty doesn’t harden?
Not at all! Non-hardening, oil-based wood putty is designed to remain pliable and is perfect for applications where flexibility and adaptability to changing conditions are required, such as window framing or door installations.
Can I make wood putty harden faster?
Speeding up the drying process can be achieved by applying the putty in thin layers and allowing adequate ventilation, although it’s always best to follow the manufacturer’s instructions for optimal results.
What can I do if my wood putty has hardened in the container?
If your wood putty has hardened in the container, adding a small amount of acetone or a specialized wood filler thinner can help to soften it, but ensure to stir thoroughly for even consistency.
Can I still use wood putty that hasn’t completely hardened?
Absolutely! In fact, semi-hardened or pliable putty can be easier to work with, especially when filling small gaps or making minor repairs to wooden surfaces.
What’s the difference between wood putty that hardens and one that doesn’t?
Hardening wood putty, often water-based, is great for larger, more structural repairs, while non-hardening, oil-based wood putty is ideal for minor fixes and adjustments where flexibility is necessary.
Did I cover all you wanted to know about: Does Wood Putty Harden?
In this article, I have deeply discussed Does wood putty harden and what are advantages you can get from wood putty over wood filler because of being a non-hardening paste.
Furthermore, we have discussed how can you make wood putty dry faster based on oil-based wood putty and water-based ones.
Wood putty can either harden or stay pliable based on its type. Water-based wood putty hardens upon drying, ideal for significant structural repairs. Oil-based, non-hardening wood putty remains flexible, making it perfect for smaller repairs and areas where adaptability to changing conditions is required.
However, in my experience, Wood putty is great to use if you’re a beginner in woodworking because you can apply it to the areas easily even after you are done with the woodworking project and wood putty has great flexibility over environmental changes.
It can contract and extract along with the wood smoothly.
If you’re not interested in using wood putty or wood filler, the best alternative is caulk for filling wood gaps, cracks, frames, trims, corners, and sealings
Hope this article gave you a proper understanding of how you can apply wood putty to your next woodworking project without any issues.
So, let’s give it a try!
I’ve had to use DAP wood plastic on a dresser…is this wood putty ? Also can I paint then polyurethane it and will it chip away or will it harden well ? Thanks
Hi Dab!
DAP wood plastic is a Wood filler. It is set into the wood, you can cover it simply with a coat of paint and apply polyurethane over it. Yes, it’ll harden well.