How to Make your Own Wood Filler

I was recently redoing my Thonet rocking chair and wanted to keep a natural finish. There were some small cracks and holes in the wood I found as I sanded the chair down. But I really wanted the patches to match the sanded finish. So instead of using the wood filler I’d bought, I decided to make my own. Want to try too? Here’s how to make your own wood filler.

why make your own wood filler?

Here’s the thing, using wood filler from the store is so easy. You pull it off the shelf, put a little where you have cracks or holes in the wood, sand, then you’re good to go. Store bought wood filler isn’t too expensive and a tub of it lasts awhile.

If you haven’t used wood filler before, I like to use it when working on furniture or millwork or hardwood floors. Anytime there’s an imperfection, I just fill the hole or crack with the filler that feels like putty. If the hole is deep, a few coats of wood filler are needed. Once filled, just sand for a smooth finish. Unlike caulk, wood filler won’t shrink and still show the hole.

Usually I paint over the wood putty so it doesn’t matter the color it is. But when going for a wood finish, it’s important for the filler to match the wood. I’ve seen skilled woodworkers make their own so I decided to try it. Here’s why-

close color match

When making custom wood filler, you use the wood from the furniture you’re working on to create the filler. By doing this, you get a close color match to the wood. The sawdust is mixed with wood glue. If you use white wood glue (as opposed to the more common light brown), it’ll get you the closest color match as possible.

convenience

One great thing about making your own wood filler, besides it makes you feel like the ultimate DIYer, is that it’s super convenient. You can whip it up and not have to run to the store when working on a project. Easy peasy! Plus it saves you money. It’s only two ingredients and one of those (the sawdust) is free.

SUPPLIES

white wood glue

palm sander

paper plate or bowl to mix in

paint spatula or plastic knife or popsicle stick (anything to stir the wood putty with)

220 grit sandpaper

step 1- make sawdust

Start by sanding the piece of wood you’re doing your project with. If you aren’t going to sand the wood, you can buy a piece of the same wood from the hardware store and sand that.

Make sure to use sand that’ll match where you’ll be patching. For example, I sanded off lots of red stain. If I would have used that sawdust, it wouldn’t match very well. Also avoid knotty areas which might be darker than the rest of the wood.

If your sander has a collection bag, it’ll be super simple to collect the sawdust. My palm sander doesn’t have a bag, so I put pieces of cardboard under my work area, sanded using fine sandpaper (220 grit), and then dumped those into a paper bowl.

Hint- if it’s super windy, watch out for a wind gust blowing all the sawdust away. This happened to me and was super annoying (and slightly comical 😉 ).

step 2- mix the sawdust with wood filler

Next, add wood glue to the sawdust you collected in the bowl. Note, in the picture above, that was too much glue to sawdust ratio. I had to add more sawdust for it to work- you want it to feel like a thick putty. Stir well until completely mixed together.

Note, I think mine could have been thicker. I should have used more sawdust!

I used a painter’s spatula for stirring since I had it on hand. A plastic knife or popsicle stick would work nicely too.

Make sure that after you mix the wood putty, you’re pretty much ready to use it. It drys quickly, so try and do your patches within 10 minutes of making the wood filler.

step 3- apply the diy wood filler

And now, use the spatula you mixed the wood filler with to fill the hole with the diy putty. Try to fill the hole and then scrap any extra off. The less excess, the less you have to sand later.

Let the filler dry completely.

While it’s drying, wash the paint spatula with warm water and soap since it will be difficult to remove once it’s dried on. Throw away any unused wood filler- it needs to be mixed fresh to be used.

step 4- sand it smooth

Finally, once it dried I was surprised that it had dried darker. I was a little concerned, but after lightly sanding with the 220 fine grit sandpaper, the area looked like an excellent match and was barely visible.

I did a little test (not pictured) where I tried filling a few holes with the wood filler I bought from the store. It was easier to use, but much lighter in color. I’m happy with my experiment of making my own wood filler!