Wood fillers are very handy for making minor repairs on wooden furniture. They can be sanded and stained to mask imperfections and blemishes in the wood. But one question a lot of folks wonder if they can screw into wood fillers too.
You can screw into a wood filler, particularly epoxy and multipurpose wood fillers. These types are durable, carvable, and can hold on to nails and screws. However, wood fillers aren’t natural wood and may not support heavy loads like door hinges.
The rest of this article includes more detailed instructions for drilling into wood fillers. It also contains some helpful tips for the best results.
How To Screw Into Wood Fillers
As I mentioned before, the best wood fillers to screw into are epoxy and multipurpose wood fillers. Screwing into any of these is quite simple and involves two basic processes:
- Applying the wood filler correctly.
- Driving in the screw.
The way you apply wood filler can significantly determine your success with screwing into it. You can get away with a degree of imperfection when using wood fillers mainly as “cosmetics” to mask blemishes in the wood.
But for screws, you need to apply the filler correctly so that the finished product is as sound as possible and will support screws without splits or cracks.
And to do this, you’ll need the following materials.
- Putty knife
- Tack cloth
- Paint or stain (optional)
- Multipurpose or epoxy wood filler. I recommend using the Abatron WoodEpox Epoxy wood filler from Amazon, as it’s shrink-free and easy to sand and paint.
Like many wood repairs, the first step is to prepare the wood surface so that the filler bonds well to it. Scrape off any loose paints or stains and get rid of splinters. The surface must be smooth to the touch and have an almost “finished” feel to it.
After removing splinters and loose chunks of wood, you also need to smooth out the rough edges with sandpaper.
Once the edges have been smoothed out, use a shop vac to remove the wood dust and any other debris in and around the work area. Wood dust can prevent the filler from sticking well to the wood, so it needs to be removed.
But if you don’t have a shop vac, wiping the area with a damp tack cloth will work well too.
It’s not mandatory to sand down the rough edges, but doing so will make the work more manageable when it’s time to put in the wood filler. When sanding, remember to cover your nose with a construction mask, as wood dust can cause nasal cancer.
Mix the epoxy resin and hardener as instructed by the manufacturer. Once that’s done, use a putty knife to apply the mixture, starting at one end and gradually working your way to the opposite end.
Be sure to press down with the knife so that the filler gets to the deepest areas and no air is trapped underneath. Trapped air will affect the durability and strength of the filler and its ability to hold firmly to screws.
It’s also wise to overfill the hole in case of any shrinkages that may occur as the epoxy cures. However, once cured, epoxy doesn’t shrink, and you can use sandpaper to make it level with the surrounding wood.
After applying the filler, allow it to dry completely. Manufacturers regularly indicate the minimum amount of time needed for the wood filler to dry and harden. Once it’s completely cured, sand down the excess and paint it to match the color of the surrounding wood.
You can now screw into the wood filler.
Two things are necessary when screwing into wood fillers:
- Use small and lighter load-bearing screws.
- Make pilot holes for the screws.
Despite the strength and durability of epoxy and multipurpose wood fillers, they aren’t actual wood. So you need to consider this when screwing into wood fillers.
Ensure that the screws you drill into the wood filler will not bear heavy loads like door hinges and bed frame brackets. Wood fillers won’t support heavily loaded screws and can crumble from the immense weight of a door or bed frame.
But they will serve perfectly from small and lighter load bearing works.
Epoxy is tough when dry, and you may need to make a pilot hole first before you drive in the screw. A pilot hole is a smaller hole that’s drilled into the material before driving in a screw. The hole serves as a guide for the screw, allowing it to go in more easily and prevent damaging the material or the screw itself.
Screws are either self-drilling or self-tapping and although many people use the names interchangeably, they’re not the same. Self-drilling screws are those with the ends shaped like a drill bit, while self-tapping screws only have the threads running down the length.
With self-tapping screws, you must make a pilot hole, as the screws can’t pierce through the hardened wood filler. But if you’re using a self-drilling screw, it’s possible to drive the screw in without a pilot hole, but you stand the risk of cracking or splitting the wood filler if you do this.
Here are some valuable tips for best results when screwing into wood fillers.
- Only screw into two-part epoxy and multipurpose wood fillers. Any other wood fillers will likely not hold screws and nails for long.
- With two-part epoxy, be sure to mix the resin and hardener vigorously for at least one minute before applying. Doing so will produce a uniform and stronger mix.
- Some manufacturers indicate short drying times for their wood fillers, but it’s best to allow epoxy fillers to dry for up to 24 hours before putting in screws or nails.
Some, but not all, wood fillers can be screwed into. Two-part epoxy and multipurpose wood fillers can hold screws and nails reasonably well, provided they were correctly applied and given enough time to dry and harden.
However, the screws shouldn’t be linchpin screws that bear overly heavy loads. And you need to make pilot holes in the wood filler before driving in the screws to prevent damaging the material and even the screws.