Can You Apply Epoxy Paint over Painted Surfaces? (How-To)

Epoxy flooring is one of the most durable floor finishes. You can use it on different floors. But can you put epoxy flooring over a painted surface?

You can put epoxy flooring over a painted surface but it’s advised to sand the finish lightly to remove any grime or dirt that can repel the new finish.

If you want a colorful finish, you should pick a colored finish that has the same color as the old paint. Avoid using clear epoxy as it gives you a dull finish.

Oil-Based Paints

You should only seal oil-based paint before applying epoxy resin. That’s because oil-based paints when dry form a glossy sheen that prevents a new coating from sticking over it.

So, you should prime or sand the glossy finish so the epoxy resin can stick over it. You can also seal it with polyurethane, but the finish won’t be as good as removing it completely. 

Epoxy flooring is a two-part finish that has a hardener and resin. The resin and hardener must bond in a chemical reaction to produce an ultra-thick finish. But, the formula of the oil-based pants will interfere with the chemical reaction of the epoxy resin and prevent it from drying properly.

On the other hand, you don’t have to seal a water-based finish before epoxy. That’s because they doesn’t have a glossy sheen that repels a new coating. 

Related Read: How To Apply Polyurethane On Concrete?

How To Put Epoxy Floor Over Existing Paint?

Putting epoxy floor over existing paint isn’t hard, but you won’t get good results if you don’t prep the surface first. 

Here are the tools you need:

• Water
• Clean Rags
• The Required Type Of Epoxy Floor
• Sandpaper
• Paint Tray
• Paint Shield
• Foam brush or Roller
• Large Drop cloth or Drop Sheet
• Tape
• Sealant
•  Primer
• Rubbing Alcohol (Optional)
• Oil-Based Polyurethane (optional)

1. Prep Your Workspace

First, prep the workspace. Tape the bottom of the walls and doors so the paint doesn’t get on them. You should also remove all objects and furniture. Open all windows and doors for adequate ventilation.

2. Tape A Large Drop Sheet On The Floor

Next, check if the floor is dry and ready to be painted. To do this, place a large drop sheet on the floor. Then tape the edges of the sheet to hold it in place.

Leave the drop sheet for 24 hours, then, lift it to check if the underside is wet. If the drop sheet is wet, you shouldn’t put paint on the floor just yet. Wait 2-3 more days. If the drop sheet is dry, you can go ahead with the task.

3. Sand The Existing Finish

You should sand and scuff the existing finish to improve bonding. When you sand the finish, you create tiny holes and scratch marks on the coating that the epoxy resin can soak into after it has been applied.

To sand, use fine-grit sandpaper. You shouldn’t use coarse sandpaper as it can remove the entire finish For large surfaces, use a power sander. After sanding, remove the dust and dry-clean the surface.

4. Seal The Paint

If you are applying epoxy resin over oil-based paint you need to seal the finish first. Apply 3 coats of oil-based polyurethane over it and let it dry. 

However, for better results, you should remove the existing finish entirely. 

5. Clean The Floor

Clean the floor to get rid of any stains or dirt in it. If there are oil-based stains, use a mild solvent such as rubbing alcohol to remove them. Don’t use a solvent that can damage the finish underneath.

For example, solvents like mineral spirits and paint thinners can remove the existing finish, so you shouldn’t use them for cleaning.

Related Read: Can You Apply Latex Over Polyurethane?

6. Mix The Epoxy Floor

The epoxy floor is a two-part paint that must be mixed correctly to create its finish. To do this, you need to follow the manufacturer’s instructions.

The usual ratio is to mix equal parts of the resin with the hardener. The resin is epoxy paint, while the hardener is the part that makes it strong.

You should mix it in a large container (bucket). Stir the mixture only if indicated by the manufacturer. After mixing, cover the container (or bucket) and wait 1 hour. This allows the ingredients to be properly mixed and settled. 

Pick an epoxy finish that has the same color as the existing finish. If you use clear epoxy over a painted finish, you will get a dull finish. 

Related Read: How Long Does It Take Epoxy Paint To Dry?

7. Prime The Floor

Priming over a painted surface isn’t mandatory, but it helps (a lot). The primer will cover imperfections and holes in the existing finish and create a textured base coat that the new coating can stick to. 

Apply 1-2 coats of primer over the surface. You must use a primer that is compatible with epoxy resin.

8. Apply The Epoxy Floor

When the floor surface is prepped and the epoxy has been well mixed, apply it.

Here are 5 tips you need to follow when applying it:

1. Apply thin coats – You shouldn’t start with heavy coatings because the epoxy will be very difficult to control. Also, start painting at the corners first.
2. Use a small brush for edges – If you use a large brush, you can accidentally paint the walls too. After painting the edges, you can use a larger brush for the remaining surface. You can also use a foam roller to cover the wider areas.
3. Use a Paint Shield – Use a paint shield in tight corners. The shield will prevent you from applying the paint on areas you don’t want to.
4. Apply 2 coats –  You need 2 coats of the epoxy floor for a strong and durable finish. The paint takes 24 hours to dry for a re-coat. You need two cans of epoxy resins and a hardener. That’s because once the resin and hardener is mixed, you must use it within 2 hours. So even if you don’t finish the first mixture, the leftover will have gone bad before you can apply a second coat.
5. Don’t Use a Spray Paint – Never apply epoxy paints using a spray gun or sprayer.

9. Seal The Epoxy Floor

Once the final coating has dried (cured), seal it with a sealant. The sealant will produce a glossy layer that protects the finish from moisture, water, or other damage. 

However, this is optional as the epoxy finish is durable on its own. 

What Type of Paint Does Epoxy Stick To?

Epoxy floor sticks to water-based and acrylic paint, but doesn’t stick to oil-based paint. This is because the formula of an oil-based finish can interfere with the epoxy’s chemical bonding process. So, it’s recommended to only use it over water-based finishes. 

Epoxy is a two-part paint that consists of a hardener and resin. You must mix both parts to create a chemical reaction that will produce a strong finish. However, oil paints have a formula that interferes with its bonding process.

So, to apply it over an oil-based finish, you have to seal the existing finish first. You can seal it with 3 coats of polyurethane.

To know what type of paint the floor has, you can use the water test: Put a few drops of water on the finish and leave it for a few minutes. If the water turns dark, the finish is oil-based. If the water doesn’t change color, the finish is water-based. 

How Long Will it Last?

On average, an epoxy finish will last 20 years on the concrete floor before it shows signs of chipping and dents.

Epoxy paint is a strong, durable finish that will last decades if applied correctly. However, there is no specific time frame on how long it will last since it depends on several factors. Moisture, traffic, and dirt can influence how long will it last.

For instance, epoxy resin will last longer on a bedroom concrete floor than in a concrete garage floor. This is because garage floors will see a lot of heavy action, traffic, and grease. All of which can reduce the durability of the finish.

However, you can expect it to last up to 20 years on concrete.