Furniture Repairs: Bondo vs. Wood Filler

Hi HawkinsWoodshop.com friends! As a furniture refinisher I come across well-used and sometimes beat up pieces that require repairs more often than not. I see anything from small scrates on furniture tops to chunks of wood missing on corners or cross supports. Today I’m going to share how I used Bondo instead of wood filler for furniture repairs and how they compare.

Bondo All-Purpose Putty/Body Filler

For large repairs Bondo Body Filler is the best product I have found. It’s actually made for auto body repairs but works great as a wood filler. This product gives more structure and you can rebuild chunked corners and large gouges. It comes in a quart with a cream hardener that you mix together before application. The red cream hardener is my favorite because it’s easier to see that it has been fully mixed in to the gray filler base. If it’s isn’t a consistent pink-mauve color it’s not mixed well enough. Be sure to follow the manufacturers directions for mixing and application. If enough hardener isn’t mixed in it will not properly cure. You will have to scrape it off and re-do the fix.

Bondo can be used for many household and automotive projects including exteriors use. It has entirely replaced wood filler for me and I would reach for this product any day over wood filler.

     Tips:

• I find about a 1:3  ratio of hardener to filler works the best.
• Use a scrap piece of cardboard or a disposable plastic lid to combine the product on.
• Mix small amounts at a time as it set very quickly. There are just a few workable minutes once the hardener is added
• It’s able to sand in 30 mins up to a few hours depending on how large of a repair you are doing and how thick it is applied.
• Apply with a plastic putty knife and smooth as much as possible so you have less sanding to do once it is dry.
• This stuff is perfect for filling in old hardware holes if you are changing or replacing hardware.
• If a large repair needs to be filled it may take more than one application. Don’t try to do large, deep repairs all at once or the bondo underneath won’t harden all the way or it will take an extremely long time to harden completely.
• Purchase more hardener separately because the combo kit only comes with a small tub that will not be enough for the whole can of filler.
• Wear a respirator or work in a well ventilated area because this product does have a strong smell.

I repaired some deeper scratches and a broken corner (left side) with Bondo on this LA Period Nightstand. Once everything was sanded and painted all the imperfections the nightstands had were not visible. In the photo above I used a white cream hardener so the color just looks gray instead of pink.

Bondo Glazing Putty

Bondo’s glazing putty is actually the first Bondo product I ever used years ago. A Sherwin Williams employee recommended it to me. It comes in a tube and doesn’t need to be mixed with a hardener. It’s ready to use right out of the tube. I actually use this product so much I had it as a “subscribe and save’ on Amazon where a tube would automatically ship every month.

This product does have a smell so work in a well ventilated area. The glazing putty dries relatively quickly and I find it is best for surface scratches and small dings. It is also great as the final fill over the Bondo Body Filler. It sands to a perfectly smooth surface when applied correctly. The other things this can do is minimize or hide open wood grain. If you sand or take off an original finish but don’t want the wood grain showing through your painted finish this can hide that. Since glazing putty is a red color you definitely see where it was applied. When sanded it leaves a pink dust everywhere.

Tips:

• Once dry sand with fine grit sandpaper to get an extra-smooth, ready to paint finish. Sanding before it’s fully dry will result it it gumming up the sandpaper.
• Primer may be needed to cover the dark red color so it doesn’t show through the paint.
• Apply in thin coats, not over anything repair deeper than 1/4″ or wider than 1/2″
• Use as the final fill coat over Bondo Body Filler as needed.

Wood Filler

Let’s chat a little bit about wood filler. I entirely stopped using wood filler a few years ago. Why? It just doesn’t perform like I need it to. Most wood fillers aren’t as smooth as Bondo and some have bits of wood dust in them which make it hard to get a smooth, even fill that doesn’t look dimpled. Wood filler also doesn’t cure or harden well enough in my experience. Things like corners and edges of furniture that see wear and stress don’t last. I need a product that will withstand the wear and tear that those areas see.

There are stainable wood filler products for wood furniture repairs where that surface will be stained. As I mentioned above in my experience these wood fillers have actual bits of wood sawdust in them to absorb stain. I have tried applying stain over stainable wood filler before and it has never looked great. It doesn’t take the stain like regular wood. I believe a big reason is the fillers in it that bond to the surface and bond all the ingredients together. Usually I resort to paint when there are furniture repairs. If it works for you, great!

     Problems with Wood Filler (in my experience)

• Wood filler tends to shrink and crack.
• It doesn’t smooth out as well which can be visible when paint is applied.
• Doesn’t dry very hard and can be easily dented and stay malleable with larger repairs.
• The good: it’s water based and doesn’t have strong odors

If you have questions or want to share the products you use of furniture repairs, leave them in the comments.