Make Wood Filler With Sawdust – How And Why?

Wood filler, the beginner’s friend.

Wood filler is often used to repair or restore damaged wooden articles by masking any cracks or indentations in the wood. The process involves filling the crack and after allowing the filler to cure, sanding it to a smooth, level finish. While this being the more common use for “wood makeup”, I find it to also be a great beginners woodworking tool.
As beginners, you often find yourself faced with a small blemish with the potential to remove from the professional look you might be aiming to achieve with your latest fine woodworking project. In these scenarios, a little wood filler can go a long way.

A commercial wood filler is inexpensive and comes in a range of tones to match whatever wood you may be working with but a perfect match will always be a challenge.
It is for this reason that I almost always chose to make my own. When making your own wood filler you can much closer match the color of the wood you’re working on.

How to make your own wood filler?

Well, it’s as easy as mixing wood glue and fine sawdust.
While the recipe to make your own wood filler with sawdust is not at all a complicated one there are some small considerations.

  • The glue to sawdust ratio?
    Keeping in mind that the saw dust it what gives the color to your DIY filler while the glue will be the bonding agent, finding the right ratio of glue to sawdust will produce a putty-like compound.
  • How fine is fine sawdust?
    The finer the better. The sawdusts function is mostly to act as a pigment and therefore should be very fine. This dust is ideally harvested when sanding the workpiece.
    Using a coarser sawdust will produce an undesirable texture.
  • The color of the sawdust?
    This is where the true beauty of mixing your own wood filler comes in. Harvesting the sawdust from the workpiece the wood filler will be used on allows you to exactly match the color and so making the area where the wood filler is used as inconspicuous as possible.

Mixing and applying

  1. Collect fines in a container
    Collecting the sawdust should be done from the workpiece it will be used on as to match the color. In addition, it should be as fine as possible. Ideally harvested after sanding an area of the workpiece.
  2. Mix in wood glue
    Gradually add glue to the sawdust while mixing until a putty-like consistency is achieved.
  3. Apply to hole or crack
    Using a scraper, apply the DIY filler to the area it is to be used. In the case of deeper cracks and holes, try to get the wood filler as deep into the crack as possible. With the scraper, remove any excess filler from around the area and leave to cure.
  4. Sand it down
    After the glue has cured use a fine grit (200+) sandpaper to sand the area to a smooth finish.

Final thought

Making your own wood filler will save you from wandering around your local hardware store like a lost soul looking for the right filler to match your project and in addition spare you from the feeling of disappointment after arriving home just to find you made the wrong selection.
It also means you don’t have to dedicate a special area on your shelf for the range of different tones of wood fillers for all the woods you may be working with.

Happy woodworking!

 

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Posted by Jean

Website: http://woodworkjunkie.com

This article has 22 Comments

  1. Thanks for the tip! It’s frustrating to have cracks in wooden furniture and honestly, I didn’t know what wood filler was. Thanks so much for the walk through. I will definintely remember this in the future. It’s crazy how the cracked part blends right into the rest of the wood after this process is complete.

  2. I am waiting for the clear Loctite Go2 glue to dry so that I can sand the model boat and see how my repair turned out.

    I had some shavings from where I had planed the edges of the mahogany plywood and I put the shavings between 2 sanding blocks to try to produce sawdust. This was only partly successful – I screened the result repeatedly with hardware cloth (fine mesh screen) and got some passable sawdust.

  3. I recently saw this done by the woodworking king (I think). However, a review of this and five other techniques were compared and the method that seemed to look and feel best was use of bondo. Just an interesting youtube video if you want to check it out.

      1. Does it matter if you use white or yellow glue? I use tightbond, im worried about staining the wood yellow.

    1. Hi Bill,

      This method works best when sanding the object you want to fill and using the dust generated by that. This allows you to better match the color of the wood.

  4. Would the saw dust from my Mitre saw work. I am looking to fill some decent size blemishes in cedar.

    1. It may be too rough for wood filler. You could try to separate the fine dust by putting the miter saw dust through a fine sift.

  5. I make lots of very fine wood dust with my belt sander. Wondering what type of glue is best. The ordinary wood glue tends to shrink over time when I did it with Elmers. Any thoughts or advice.

  6. Made a lovely paste,perfect colour match and went on like a dream BUT in the morning it had turned black.
    Your comments would be much appreciated
    Kind regards
    Phil

    1. Hi Phil,

      This is not a problem I have experienced myself. Could it be possible that the glue you are using is causing the dark color of the dried product?

  7. Hi Jean
    I’ve only ever made it using PVA based glues the last one was titebond 111 and the results are always the same ie black after 24 hours. I’ve tried it with all sizes of sawdust right down to fine powder and found fine powder much more usesble but no difference in colour.
    Would love to find out why this is happening. Are there any glue manufacturers out there that might advise?
    Phil

        1. What I thought was an easy question has not turned out that way.
          Have done test samples that indicate percentage of sawdust makes no difference to the blackening effect unless you add so little that it really remains a glue rather than a filler. Have tried it with wood shades from pine thro to darker woods, again no difference, at low temperatures up to room temperature, no difference. So lm left scratching my head.
          Could it be that the glues too old??

  8. Have you thought about and ruled out the container or utensil used for mixing?
    Perhaps it’s a chemical reaction. I can’t imagine old glue would do that, rather it would just dry up and be unusable.

  9. I just finished a table top with the same poor results using Titebond III. I turns dark and was very disappointed. Has anyone tried Gorilla glue that is clear? I have not tried it yet.

    1. Yes and it is no better. Still looking for the correct glue. In the morning i am going to try polyurethane as the glue

  10. I know that using metal tools with oak sawdust and glue will cause a reaction turning the mix black.

  11. We used this method on our redwood cedar porch floor. Sanded well too to try to remove all glue that dried on wood around cracks. We just finished staining and some spots where the glue wasn’t 100% removed on either side of the crack it took the stain lighter and glossier. I can kive with that maybe, but the other problem is everywhere there was filler and we sanded well, there are blotches in the stain on both sides of what we filled. Like a smoky grey was added to the stain. Very upsetting after putting in so many hours to professionally prep the wood.

    Would a polyurethane coating help?

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