We’ve all come across a project where you need to use wood filler to fill a gap or hole
Wood filler can make small holes seem like they were never there, especially if you paint over it with a matching stain.
But can you screw into wood filler?
This can be an essential question for many larger projects.
In this post, I’ll answer the question “can you screw into wood filler?” and much more. Let’s get started!
Is Screwing Into Wood Filler Sustainable?
Screwing into wood filler is certainly possible, but it may not be a great idea on some occasions.
If you are looking for a long-term solution, a wood filler may not be your best option if you want to maintain the structural integrity of the project.
There are many other issues with screwing into a wood filler that I’ll explore below.
Issues With Screwing Into Wood Filler
Below are some common problems when screwing into wood fillers.
Air bubbles can be a significant issue when you screw into wood filler, especially with resin and epoxy wood fillers.
Epoxy wood fillers can trap bubbles when poured, which can reduce the traction and grip that makes a screw work so well.
This problem with air bubbles is the main reason that you must remove air bubbles either manually or via heat when pouring epoxy wood filler.
Additionally, while wearing the proper protective gloves, you may elect to pat down the epoxy wood filler as it sets to release any air bubbles that have been trapped in the resin.
Your Types Of Screw
Depending on what type of screw you use, your wood filler may not be strong enough to support the screw.
When wanting to screw into the wood filler, you should consider a sturdier screw, such as self-drilling screws which are designed to easily handle hardwoods.
These self-drilling screws do not even require a pilot hole, as their tip is styled after a drill bit.
This drill bit-like tip allows the self-drilling screw to tackle any thick, sturdy material without a pilot hole.
With a strong screw like a self-drilling screw, you can screw into any wood filler, even the durable epoxy wood filler.
Size Of The Load
Due to wood filler not being as stable as real wood, the wood filler may not support much weight.
A screw set in wood filler may hold a decently-sized photograph, but if you are looking for a screw to hold up a doorway, you may want to fortify it further- or change out the wood entirely.
Wood filler with have more difficulty holding larger loads and will be able to do so for less time than real wood.
This challenge means that you will need to find a better fix for the hole in your wood before it falls apart.
If you want to fortify your wood’s hole, there are several methods available.
Wooden dowels, the thick and textured plugs of wood that average about an inch in length, are a great option for filling in holes and making them more stable for holding a screw.
Make sure that the hole can fit your wooden dowel. Place as many wooden dowels as you need, then fill in the rest of the whole with wood filler or wood glue. Use your screws, and you are all set!
Wooden Match Sticks
Much like wooden dowels, wooden match sticks can be used to plug holes.
These matchsticks are used similarly to wooden dowels, though you will likely have to use more of them to achieve the same effect.
What Wood Filler Materials Hold Screws Best?
By now, you have read plenty about the negatives of wood filler and how you may have difficulty putting screws into the wood filler.
However, it can be effective to screw into your wood filler, though certain wood fillers handle this better than others.
As with many other pieces of woodworking equipment, there are many different types of wood filler that you may choose to fill holes in your woodworking projects.
Epoxy Wood Filler
Epoxy wood filler is a wood filler that is made of a two part epoxy resin, requiring woodworkers to mix these two parts to create an epoxy solution that is strong and durable.
Epoxy solutions can cure into an extremely durable state and many woodworkers also use them as a good sealant or decorative addition.
Epoxy wood fillers hold screws the best out of these different types of wood fillers since this wood filler dries into an extremely hard state.
The only major downside is that epoxy resin is a notoriously toxic product, generating many different chemicals and expelling irritating dust while mixing in its liquid form.
Any time you are around any form of epoxy, including epoxy wood filler, it is vital that you wear the proper protective equipment.
When handling epoxy, you should wear gloves, a respirator, and protective goggles to prevent the chemicals or dust from entering any orifice.
Bondo Wood Filler
You could certainly screw into Bondo wood filler, but it may not be a good idea.
For mimicking real wood in appearance, Bondo is a great option; when sanded, stained, or painted over, Bondo will look almost identical to the wood around it.
However, Bondo has issues with strength; while stronger than Elmer’s wood glue, Bondo is not strong or tough enough to handle screws.
Elmer’s Wood Filler
Elmer’s Wood Filler may be the worst on the list, though as a putty, it is the easiest to apply and the most useful in general scenarios.
This type of wood filler is a simple wood putty that you can use to fill any holes in your projects and can be applied with your fingers and a putty knife.
Due to the putty-like nature of Elmer’s Wood Filler, it is easier to manipulate than other wood fillers and not nearly as strong.
To mimic more shapely pieces of wood, Elmer’s may be your best bet- however, you should not use it to hold screws at all.
Learn the difference between wood filler and wood putty here!
How To Apply Wood Filler To Hold A Screw
While epoxy is usually better at holding screws than other types of wood filler, it can be useless if you have not correctly applied it to your wood!
These steps will work for most wood fillers, no matter which option you choose- however, they will be best for epoxy wood filler, so keep that in mind!
Wood filler is best applied to a clean surface with no loose paint, dirt, debris, stains, or extra chunks of wood.
The first step of applying wood filler is making sure that your workspace meets these criteria- even the best wood fillers may be defeated by a dirty surface that it can have difficulty anchoring to.
Lightly sand and then thoroughly clean the area around the hole that you wish, removing any rough edges, to fill to properly prepare the wooden surface.
Prepare Your Wood Filler
Different wood fillers require individual methods of preparation.
Epoxy resins, for example, require a certain ratio of resin powder to liquid mixture to properly cure.
Certain types of wood filler may work with a hardener, which must be mixed into the wood filler.
Apply Your Wood Filler
No matter what type of wood filler you use it’s time to apply the wood filler.
With putty-based wood filler, you may use your fingers, but you will best spread most wood fillers with a putty knife or a similar tool.
You will want to add more wood filler than you would expect to the hole, as some wood fillers will shrink as they cure.
Allow Your Wood Filler To Dry
Depending on what type of wood filler you used and where the wood is, it may take anywhere from twenty minutes to four hours to dry and cure.
Wood filler will take longer to cure if it is held in a humid area, especially if you already live in a humid environment.
If your project is mobile, try storing it in the driest place available, though you will also want to keep it well-ventilated.
Sand the Surface
Depending on the type of wood filler you use, you can sand the surface where applied to give an even appearance.
Be careful not to sand too deeply, especially if you used a putty-based wood filler; these types of wood fillers are softer and may not be able to stand up to excessive sanding.
You may need to apply a second layer of wood filler if you accidentally sand too deeply into the first layer.
Apply Finish Or Paint
Once your wood filler has set into its hardest form and the surface is sanded, you may choose to cover it with a finish, stain, or paint to make it look even before you screw into it.
Paints, finishes, and seals also provide an additional protective layer to help keep screws more secure.
Once you have finished all the work on the wood filler itself, you can do the most simple step – simply screw into the wood filler.
You should have no problem screwing into wood filler, especially if you used epoxy resin, as it will be quite hard once it has set.
Once again, many experts recommend that you use self-drilling screws when screwing into the wood filler, as these screws are particularly stable and sturdy.
Final Thoughts on Can You Screw Into Wood Filler
Ultimately, while you can certainly screw into wood filler, many small variations can make it a bad idea depending on your needs.
Depending on the project you’re working on, it might not be the best idea to screw into wood filler if you need to maintain the projects structural integrity.
However, smaller projects that don’t need to bear much weight may be perfectly fine being screwed into wood filler.
It’s important to remember that you’ll want to use self-drilling screws when screwing into wood filler to ensure the most secure hold possible.
Also, some wood fillers are better than others when it comes to holding screws. Ideally, you’ll want to use a quality wood filler like an epoxy resin to ensure that your screws will stay put.