With plenty of low-cost commercial wood fillers and wood putties available, you might wonder why you would want to make your own DIY wood filler. Off-the-shelf wood fillers are easy to work with, and some are tinted to mimic the colors of various wood types. Still, many skilled woodworkers make their own wood fillers.
Making your own wood filler is convenient, inexpensive, and best of all, the filler is a close match to the item you're repairing.
Why Make Your Own Wood Filler
Do-it-yourself wood filler is often called cabinetmaker's putty since woodworkers and fine carpenters often create their own filler to closely match a particular woodworking project. This close match is achieved by using the wood itself, by mixing sawdust from the same wood with a binder, typically wood glue.
Convenience is another reason you might want to make your own wood filler. If you run out of commercial wood filler while working on a project, you can whip up a small batch of your own in minutes.
DIY wood filler will closely match your project's wood, but it will not be exactly the same since the glue will be a different color from the wood. You can exactly match the color by following up with wax wood filler sticks.
DIY wood filler works well for filling small holes and cracks but is not strong enough to bridge large holes, cracks, and gouges. As with any wood filler, your DIY wood filler will not be able to match the wood grain. Most wood glues are lightly brown-tinted, but if you can find white wood glue, it will create a better color match.
Equipment / Tools
- Electric sander, file, or rasp
- Putty knife
- FIne-grit sandpaper
- Tack cloth
- Scrap wood
- Craft stick
- Wood glue
- Wax wood touch-up markers
Make Some Sawdust
Sand a piece of sample wood that matches the project material. A sander with a collection bag makes it easy to collect the sawdust, but using a file, rasp, or sanding by hand will also make perfectly usable sawdust if you don't have a power sander. If you're cutting wood on an electric miter saw, that's another fast way to create sawdust without wasting wood.
Gather a pile of sawdust onto a piece of cardboard or scrap wood. It's important to sift through the sawdust and remove any large particles, wood or metal shavings, or other impurities. Running a magnet through the sawdust will pick up any ferrous metal. Wrap the magnet in plastic, then discard the plastic to separate the shards from the magnet. Other items will need to be identified by sight and removed individually.
Mix the Wood Filler
Gather the cleaned sawdust into a small pile or in a paper cup. Add wood glue and stir with a craft stick, adding more glue until the mixture is a thick putty, roughly the texture of cookie dough. Avoid adding so much glue that the mixture becomes runny. Wood glue hardens relatively quickly, so don't take your time—you have about 10 minutes of total working time to prepare and apply the filler.
Form the mixture into a workable dough that you can roll between your fingers. If the dough has already begun to stiffen, it will be difficult to apply to the work material. If this happens, start with a new batch and slightly increase the amount of wood glue in the mixture. Once the proper texture is achieved, move immediately to the application of the filler to the work material.
Apply the Wood Filler
Push the putty by hand into the gouge, scratch, or hole in the work material, then remove excess by hand. Working quickly, use a putty knife to flatten the wood filler and scrape away excess. Let the filler dry completely.
Wash off the putty knife right away with warm water and soap. The filler is difficult to remove from tools once it dries. Discard unused wood filler. Stored wood filler will harden and cannot be saved.
Finish the Project
Sand the filled area very lightly with fine-grit sandpaper. It will not take much effort to sand the area smooth. Avoid over-sanding, which will gouge the patch. Avoid sanding far beyond the patch area as this may embed sawdust in the rest of the wood. Wipe the area clean with a tack cloth.
Touch Up With Wax Stick
Crayon-like wax sticks in various colors help you touch up the wood putty after it has dried if it doesn't completely match the surrounding wood. Lightly draw over the touch-up with the wax stick, adding other colors as needed. You can smear the colors with your thumb to mix them and to soften the effect.