Sawdust and Glue = Wood Filler?

Sawdust and glueDo you have a wood repair project that requires holes or cracks to be filled?

Well here’s some great news. I’m going to tell you how I make a wood filler using sawdust and glue here at the restoration shop.

It’s incredibly quick, simple and durable. Plus, a wood repair made with sawdust and glue is inexpensive and rewarding to know that it was done with a “like material”.

Before getting started I would like to mention that this filler is not recommended for any kind of structural repairs.

Okay, let’s get on with it.

The Project

The image below shows a good example of where I often use sawdust and glue as a filler. This is the bottom of a chair rail that will be repaired with this technique.

Chair rail with many tack holes

Having been re-upholstered numerous times, you can see the rail had become chewed up from all the tacks. To make sure new upholstery tacks will hold properly, I use a homemade wood putty mixed from sawdust and glue.

Here’s a Super-Long Material List

  • Wood glue
  • Sawdust
  • Putty knife
  • File
  • Sandpaper

Just about any wood glue will work to make this filler. Wood glue (yellow or white), hide glue and even epoxy glue. Because epoxy glue dries quickly, I use it on smaller repairs.

As for sawdust, my preference is the fine saw dust from sanding, rather than wood shavings which don’t mix well. I usually get it from underneath the disc sander and band saw. When I want to color match, it helps to use sawdust that is the same wood specie as what’s being repaired. It’s never a perfect match, but a good start.

On this project I used a variety of sawdust and Titebond yellow wood glue.

The Mixture

I start by pouring glue into a small pile of sawdust and mix the two together with my putty knife. There’s no particular ratio or formula. It’s just a matter of adding a little more of either material, until I get a desired consistency.

sawdust and glue mixture ready to be used as filler

A well-mixed slurry of sawdust and glue will be workable enough to hold some shape, but not runny. A dry mixture will not adhere correctly, and a runny mixture will shrink and need additional applications.

Application

As seen below, a thin layer of glue is put on the surface just before applying the wood filler. Doing this strengthens the damaged wood and helps the filler bond well.

Wood glue applied before filler

Using the putty knife, the filler is applied by repeatedly packing it into the damaged area. Then smoothed out as best as possible.

The filler shrinks as it dries, so I leave excess to compensate. When filling deeper holes or cracks, I find it best to do more than one application to avoid air pockets.

Wood filler applied onto damaged chair rail

Finishing Touches

Dry time varies depending on which glue is used and the size of the repair. I usually let dry overnight before preparing the surface for any finishing touches.

Course texture of dried saw dust and glue filler

Once dry, the filler is very rough and sometimes jagged. Kind of like the texture of heavy tree bark.

The majority of this coarseness is quickly taken off with a file. Then I use sandpaper to smooth and flush. If I were repairing a different kind of surface, I might use a plane, or just sandpaper, and not a file.

Depending on the project, the repaired surface can then be colored, stained and finished if needed. Since the rail on this project was going to be covered with upholstery, it was left as seen below.

Tack holes filled and sanded flush

What Next?

Try it out. You’ll find it’s very durable and great for all sorts of wood repairs.

Leave a Reply

Your email address will not be published. Required fields are marked *