Apply Wood Putty For a Strong Bond

  • 01 of 07

    Apply Wood Putty For a Strong Bond

    Apply Wood Putty - Crack to Be Filled
    Crack to Be Filled. © Lee Wallender; licensed to

    You need a crack, hole, or joint in wood filled. But it's not just about aesthetics; it's also about providing a secure bond.

    Let's look at the two different types of wood putty, and how one of them is completely the wrong type to buy:

    Water-Based vs. Petroleum-Based Putties

    First, you've got products, such as Elmer's Wood Filler, which is water-based and rather crumbly. I think of this and similar brands as being like "The Spackle of wood." Spackle is used to cover up...MORE holes in drywall and looks great when painted over. Just don't expect it to provide any structural stability.

    Same with the water-based fillers. They aren't meant to hold a very strong bond. They are meant to fill, to cover, and to eventually be painted over or stained.

    What we're using in this guide is a petroleum-based wood putty; in this case, the brand is Ace Wood Filler. You'll know it's petroleum-based when it says to clean up with acetone. This type of wood putty does two things:

    1. Covers and fills (just like the water-based stuff).
    2. Bonds wood (unlike the water-based product).

    Note that wood putty isn't your first solution when all you need to do is bond surfaces. For that, use mechanical fasteners or wood glue. Wood putty is for when you need to visually fill a surface and provide structural stability.

    Continue to 2 of 7 below.
  • 02 of 07

    Use a Smaller Amount of Wood Putty Than You Think You Will Need

    Wood Putty for Strong Bond - Amount of Putty to Use
    Amount of Putty to Use. © Lee Wallender; licensed to

    Open wood fill container and mix it up with a putty knife. If it's old, it may have separated.

    It's tempting to load up the putty knife with tons of putty. Because you can always sand it off, right?

    Not right. Sure, wood putty is sandable. But after drying, this type hardens rock-solid. In fact, if you're filling a soft wood (like pine), the wood putty becomes stronger than the wood itself.

    So, go easy on the amount.

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  • 03 of 07

    Initially Use a Knife to Apply Putty

    Putty for Strong Bond - Apply with Putty Knife
    Apply with Putty Knife. © Lee Wallender; licensed to

    You'll need to work quickly, because this type of putty hardens fast. By contrast, the water-based putty is creamy and stays wet much longer.

    Press the putty into the crack and scrape off excess, making sure not to gouge into the patched area.

    Continue to 4 of 7 below.
  • 04 of 07

    After Knife, Use Finger to Press Putty In Deeper

    Wood Putty for Strong Bond - Press In With Finger
    Press In With Finger. © Lee Wallender; licensed to
    I like to follow the putty knife with my finger. Press the putty deeper into the crack. Wipe excess off with finger.

    Now what? Acetone clean-up? If you move quickly, you won't need to resort to this. Scrape putty knife off on a 2x4 or other scrap lumber.

    Wipe your fingers with a dry cloth. You should have just a few crumbly bits on your fingers that you can remove this way.

    Continue to 5 of 7 below.
  • 05 of 07

    With Electric Sander, Sand Down Smooth

    Wood Putty for Strong Bond - Sand With Electric Sander
    Sand With Electric Sander. © Lee Wallender; licensed to
    Give the putty a minimum of 30 minutes to harden. One hour is best.

    This putty dries so hard that you'll have a tough time hand-sanding it. Use an oscillating sander, starting with a medium-grit paper and following with fine grit (around 190 or 220).

    Continue to 6 of 7 below.
  • 06 of 07

    Wipe With Tack Cloth to Remove Dust

    Wood Putty for Strong Bond - Wipe Dust with Tack Cloth
    Wipe Dust with Tack Cloth. © Lee Wallender; licensed to

    You'll have a lot of wood dust and wood putty dust on the surface. This can present a problem when laying down stain, clear-coat, or paint. The liquid will mix with the dust and produce a lumpy, grainy surface--exactly the opposite of what you want from a nicely sanded surface.

    Tack cloth is ultra-sticky, and it will remove both kinds of dust. If you have a huge amount of dust, knock it off with a towel or run a shop vacuum over it to remove the majority. Then use the tack cloth to remove the...MORE dust film.

    Continue to 7 of 7 below.
  • 07 of 07

    Crack: Filled, Sanded, and Strong

    Wood Putty for Strong Bond - Finished Product
    Finished Product. © Lee Wallender; licensed to
    Here the crack has been filled with putty, sanded down, dusted off. But I see I missed a small part, top, that will need to be redone.

    Application of stain will will go a long ways towards equalizing (but not eliminating) color differences between putty and wood.