Can You Stain Over Wood Filler? (How-To)

Wood filler helps to fill and cover nail holes, cracks, lines, and gouges in wood. It’s your go-to product for wood repairs. But can you stain wood filler?

You can stain over wood filler but the wood filler has to be stainable. There are two broad types of wood fillers; stainable and non-stainable wood filler. Stainable primer is a relatively new product that is designed to absorb stain as well as natural wood. This type of wood filler comes uncolored.

Unstainable wood fillers on the other hand don’t accept stains very well. If you stain over this type of wood filler, the stain color will not set properly. Unstainable wood filler often comes pre-colored and white is a common color.

Let’s dig deeper into how possible it is to stain wood filler.

Does Wood Filler Absorb Stain?

Wood filler doesn’t absorb stain well. This is because wood filler is designed to fill and cover holes and cracks in wood. As a result of this, wood filler is usually designed to be as compact or tight as possible so it can properly cover and fill spaces.

In simple words, wood filler by design isn’t porous. This makes it difficult for wood filler to absorb stain properly. If you apply wood stain over filler-patched wood, the area will appear darker and slightly tacky. This is because the wood stain will not penetrate that spot as it should.

This means the stain will mostly stay on the wood filler and if the wood stain doesn’t penetrate, it will turn tacky. ‘Tacky” means the stain will not dry and will appear semi-solid. At this stage, the stain will be too thick to allow light to pass through making the area appear darker than the rest of the wood.

Another factor that makes the spot appear darker is the wood filler itself. Traditionally, wood filler comes pre-colored. Though the color of the wood filler is usually neutral, it still prevents the wood grain from showing. Wood stain however is usually designed to reveal wood grain. So, putting wood stain over a filler-patched area means the wood grain will be covered making the spot appear darker.

However, you should know that stainable wood filler will absorb stain. Stainable wood fillers are usually made from porous materials including sawdust which makes it possible for these wood fillers to absorb stain. You can also make your own stainable wood filler by mixing sawdust with a binding agent like glue.

Can You Stain Over Plastic Wood Filler?

You can stain over plastic wood filler. This is because plastic wood fillers are at least 70% porous wood in terms of composition. Since the wood filler is gotten from wood, it will absorb stain meaning that you can stain over plastic filler.

Plastic wood filler is usually made from wood dust and a binder. The wood filler also known as wood putty is a combination of fine wood dust or blended wood and glue. This means plastic filler is more porous than regular or epoxy wood filler and as such will accept stain.

However, you should know that plastic wood filler doesn’t accept wood stain as well as natural wood. While plastic wood filler is made from 70% wood, the remaining 30% is glue and in some cases additives.

The 30% means that some parts of the plastic wood filler will not accept stain as well as your furniture which is 100% wood. So if you stain over plastic primer, there is a chance there will be differences in the shade or color of the finish.

You should also know that you’ll have to properly stir the plastic wood filler before applying it. This is because plastic wood filler solidifies inside the can and in that state, it will be difficult to apply it without stirring first. You might even need to thin it.

Next, let’s check out how to stain over wood filler.

How To Stain Over Wood Filler?

Before we go on, you should remember that you can only stain over stainable wood filler. If the wood filler isn’t stainable, the finish will not come out well. To stain over a stainable wood filler, you’ll need a few tools and supplies:

  • Fine-grit sandpaper
  • Clean rags
  • A wood stain
  • A paintbrush or spray gun

Here is a 4-step guide on how to stain over a stainable wood filler:

1. Sand & Clean The Wood Filler

Sand & Clean The Wood Filler

This is to create tiny ridges and scars in the wood filler that the stain can seep into. Sanding also helps to smoothen the wood filler so the stain can come out smoother. You should sand with very fine-grit sandpaper.

After sanding, ensure to remove dust and wipe the wood filler with a clean cloth. If there is dust on the surface, there will be bumps in the finish.

2. Apply The Wood Stain

Apply The Wood Stain

You can apply the wood stain using a paintbrush but a spray gun will serve better as it helps with better coverage. Also, the wood stain will penetrate the stainable filler better when sprayed.

3. Wipe Off The Excess Stain

Wipe Off The Excess Stain

The next step is to wipe off the excess wood stain on the filler. If you don’t wipe off the excess, the stain will turn tacky and appear darker. Also, when you wipe off the excess stain, the stain will set and dry properly.

4. Leave The Stain To Dry

Leave The Stain To Dry

On average, water-based stains take about an hour to dry and less than a day to fully cure. Oil-based stains take longer to dry and can take over 3 days to cure.

Ensure the stain dries enough before you put furniture on it or clean it. You can also seal the stain with a top coat or a sealant. Sealing the stain will make it more durable.

Does Wood Filler Stain The Same as Wood?

Wood filler doesn’t stain the same as wood. Regular epoxy wood filler doesn’t allow stains to penetrate properly due to its compact nature.

Even the stainable primers designed to absorb stain don’t stain as well as natural wood because these wood fillers are not made from 100% wood.

Wood filler is designed to seal, cover, and fill damages in wood. The product is mainly designed to fill spaces and not absorb stains. So regardless of the advertisement and branding, wood filler will not stain the same as wood.

What Type Of Stain Should You Use Over Wood Filler?

You can use any type of wood stain over wood filler but the best type of stain to use over a wood filler is a water-based stain.

This is because water-based stain is thinner than oil-based stain and as such more likely to penetrate the wood filler than oil-based stain. Also, oil-based stains usually contain additives and chemicals that can react with the compounds in the wood filler.

You can also use Miniwax stains over a stainable wood filler. Miniwax stain manufacturers claim that “Stainable wood filler will accept any Miniwax stain and, once stained, will match the surrounding wood.”

Does Wood Filler Show After Staining?

Wood filler shows after staining. This is because wood stains are designed to be a bit transparent. The purpose of doing this is to allow the wood stain to reveal the wood grain. So if you use stain over wood filler, the wood filler will show underneath the stain.

However, you can prevent the wood filler from showing through the stain by using a few methods.

1. You Can Use Solid Stain

Solid stains are thicker than regular wood stains. Solid stains have more paint pigment and color so the finish is usually more vibrant. As such, the wood filler won’t show beneath the vibrant stain color.

Also, solid stains don’t need to penetrate as deep as regular stains so the stain will stick better to a stainable wood filler.

But you should know that if you use a solid stain over wood filler, it’s not just the wood filler that won’t show. The wood grain wouldn’t show as well.

2. You Can Use a Deep Color

If you pick a stain that has a dark color like black or grey, the wood filler will not show as much as it would if you used a light stain.

You should know that these methods will only prevent the wood stain from showing if you use them before applying the stain. Now, let’s find out how to fix wood filler showing after you have stained it.

How To Fix Wood Filler Showing After Staining?

1) You Can Use a Sealant

You can prevent the wood filler from showing by using a sealant or top coat. A sealant or top coat will cover the wood filler.

The sealant will also protect the stain from scratches and dents. However, ensure to use only a colored sealant. Clear coats like water-based polyurethane will not cover the wood filler properly.

2) Apply Wood Glaze

Another way to stop the wood filler from showing is to apply a wood glaze. You can also use any oil finish on the wood stain. This will cover the wood stain and make the finish glossy.

3) Remove The Stain

The last resort is to strip the stain and start all over again. This is often the best alternative if you want the wood grain to show through the stain as other methods will cover the wood stain, the filler, and hide the wood grain.

Final Words

Overall, you can stain over wood filler buy you must ensure to use a stainable wood filler. Wood stain will not stick to regular epoxy wood fillers.

Also, you should sand the wood filler lightly to smoothen the surface and make the finish smoother. To stop the wood filler from showing through the stain, you should use a dark stain or apply a sealant over the stain.

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