Dark stains make the hardwood floor look aged and bad. So, how to remove them?
To remove black stains from hardwood floors, sand the affected spot or use a solvent such as vinegar or baking soda to wipe the floor. Removing them is a trial and error process, so you must try different methods until they are removed.
You shouldn’t use bleach as it can damage, rust, and discolor the wood.
Black Spots Are Caused By:
The main cause of back spots on wood floors is moisture. If the wooden floor is exposed to moisture (or water) for extended periods, dark stains will appear.
Black water stains start as white water stains. That’s because the moisture (water) is at the top of the wood floor and hasn’t yet penetrated it. Once the moisture penetrates it, the stain turns dark.
Here are other reasons why this happens:
Wrong Type of Cleaner
Dark water stains will appear if you use the wrong type of cleaner. That’s because these cleaners have a formula that isn’t compatible with wooden surfaces. So, before cleaning the wooden floors, check whether the cleaner is compatible with wood.
Drink spills like red wine, soda, and grapefruit wine can cause stains on wood, especially if the floor isn’t sealed. This is because these drinks have colorants in their formula that can tint the wood floor and make it appear black.
Rust (or iron oxide) can cause dark stains on wood floors. This is common with floors that have metal railings or fittings. When the metal is exposed to constant moisture (water), it will form a frail oxide coating on the metal. After a while, the rust will fall on the floor and cause dark-brown stains.
Dark Water Stains Won’t Disappear Itself
Black water stains won’t disappear on wood floors because they have penetrated the surface, so they won’t fade out. You must sand or use a solvent to remove them.
Also, they aren’t caused by just water; other ingredients and colorants also cause them. The colorants will form a permanent discolored spot inside wood fibers. So, if you don’t manually remove them, they won’t disappear.
That’s because the colorants and ingredients won’t evaporate like water. Instead, these colorants will leave a permanent black spot on the wood. The only way to remove a permanent black spot on the wood is to sand or use a solvent.
How to Remove Black Stains From Hardwood Floors?
Removing black water stains from wooden floors is hard because they have penetrated the wood. So, to remove them, the solvent must get into wood fibers, which is difficult.
However, this post will explain how to do it. But first, here are the tools you need:
- Clean rags
- Mineral spirits
- Hardwood polish
- Baking soda or vinegar
- A soft sponge
- Wood filler (optional)
1. Clean The Affected Spot
First, clean the floor. Cleaning will remove filth, dirt, debris, and moisture. To clean it, use a clean rag. If you don’t clean it, the filth will fall into the surface while removing the stains. This can cause black spots later.
2. Use a Hairdryer
Before removing the stains, you must remove or dry the moisture (or water) from the wood. To remove moisture, use a hairdryer or heater. These tools will increase the evaporation rate of moisture. If you use a hairdryer, move it around the surface, and don’t keep it in one place.
3. Use Baking Soda Solution
To remove black spots using baking soda:
- Mix 2 tablespoons of baking soda with warm water.
- Stir the mixture to make a paste.
- The mixture shouldn’t be light as it can soak into the wood. So, make the mixture thick.
- You can add ashes to make the mixture thicker.
- Apply the baking soda paste over the affected spots.
- Leave it overnight.
- Wipe the baking soda off the wood.
Baking soda is an alkaline solution that will lift the black stain out of the wood.
If you are lucky, this step will completely remove them. If not, don’t sweat it. We still have a few steps to try out. Remember this is a trial-and-error task.
4. Wipe The Surface With Vinegar
To use vinegar:
- Apply vinegar (or mineral spirits) over the affected spots.
- Use a soft sponge to massage the area.
- Use a toothbrush to scrub the area.
- Wait 5-10 minutes,
- Remove the vinegar (or mineral spirits) residue with clean water.
- Inspect the floor.
If vinegar (or mineral spirits) didn’t remove the dark spots, it means they have penetrated the wood floor deep. But don’t worry, here’s what you should do.
5. Sand The Affected Spot
Sanding must be the last option to remove dark water stains from wood. That’s because sanding will also remove the top layer of the floor.
To sand, use fine-grit sandpaper until the stain comes off. Don’t use coarse sandpaper as you can damage the floor. 5 minutes after sanding, remove the dust and inspect the floor to see if you need more sanding or not.
6. Apply Wood Filler (Optional)
Sanding and solvents can cause gouges and dents on the floor. You must fix these issues, or the floor becomes unusable.
To fix them:
- Apply wood filler or joint compound over the holes.
- Wait until the filling compound dries (1 hour).
- Remove excess filling compound.
- Sand with ultrafine-grit sandpaper.
7. Polish The Floor
Once you remove the dark spots on floors, wax or polish them. Waxing (or polishing) will give the floor an amber-like tone and make it appear bright and glossy.
Also, hardwood wax (or polish) will protect the wooden floor from moisture and water since it’s waterproof. This means waxed floors won’t get dark water stains. Allow the wax to dry for 3 days before you use the floor.
Other Products To Use:
Let’s check some common cleaning products to see if they can remove dark spots:
WD-40 can remove dark water stains in wood, but it will leave stain deposits behind. This is because WD-40 is a blend of several solvents, including fish oil. So while the dark spot is removed, the WD-40 might also leave deposits of its formula in the wood.
So, if you use it, don’t leave it too long on the wooden floor.
Mayonnaise can remove black spots because it acts as a water displacer causing stains to come out of the floor. However, it works for fresh dark spots only and doesn’t remove old dried stains.
Toothpaste is an abrasive compound that will dark spots from a wooden floor
To use it:
- Apply the toothpaste over the affected spots.
- Use a toothbrush to scrub the affected spots.
- Scrub for 5-10 minutes.
- Let the toothpaste sit for 10 minutes.
- Remove the toothpaste using warm water.
To make the toothpaste stronger, mix it with baking soda.
Pressing iron can remove wet dark spots on a wooden floor. Since the surface is still wet, the pressing iron will dry out the moisture and cause it to disappear. However, if the dark spot has dried, the pressing iron won’t remove it.
Here’s how to use it:
- Place a cloth over the affected spot.
- Put the pressing iron over the cloth.
- Move the pressing around.
Salt can remove dark water spots by dissolving the color. To use salt, mix a few tablespoons of salt in warm water and spray the mixture to the affected spots.
Preventing Black Stains
Here are a few methods you can use to prevent them:
- Place waterproof mats or carpets.
- Avoid water spills.
- Wipe and clean stains as soon as they occur.
- Clean your wood floor frequently.
- Cover outdoor wood with drop sheets in the rainy season.
- Apply a moisture-resistant and stainless finish on the floor. Lacquer is a good protective finish that you can use.
Black water stains are hard to remove from hardwood floors because they have penetrated the surface. However, sanding or using a solvent will remove them. Once the dark spots are removed, apply a waterproof wax or sealant to protect the floor from water.
Tony is a professional painter and an author of DIY Geeks. Tony has completed over 1,000 painting projects for his clients. It's safe to say he knows what he Is talking about,