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, from concrete to wooden floors. But can you put epoxy flooring over a painted surface?

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

If you want a colorful finish, you should pick a colored epoxy flooring that has the same color as the old paint, rather than clear epoxy. Clear epoxy can give you a dull finish.

Also, if the surface you want to apply epoxy paint on has oil-based over it, you need to seal the oil-based paint first. Why? Let’s find out.

Do You Have To Seal or Prime Paint Before Epoxy?

You should only seal oil-based paint before applying epoxy. That’s because oil-based paints when dry form a glossy sheen that prevents inter-coat adhesion with epoxy. Oil paints have strong chemicals and volatile organic compounds that will clash with the epoxy resin.

So, you should use a sealant to seal the glossy sheen of oil-based paint so the epoxy resin can adhere better. Oil-based paint should be sealed with 3 coats of polyurethane or primer.

Epoxy flooring is a two-part finish that has a hardener and resin. For the epoxy flooring to be achieved, the resin and hardener need to bond in a chemical reaction to produce an ultra-thick epoxy finish on the floor. 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 water-based paint before epoxy. That’s because latex paint doesn’t have a glossy sheen or high levels of active chemicals that repeal epoxy. 

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. To apply epoxy floor over existing paint, you will need the following tools:

  • Water
  • Clean Rags
  • The Required Type Of Epoxy Floor
  • Sandpaper
  • Paint Tray
  • Paint Shield
  • A Foam Paintbrush Or Roller
  • Large Drop cloth or Drop Sheet
  • Painter’s Tape
  • An Epoxy Floor Sealant
  • Epoxy Floor Primer
  • Rubbing Alcohol (Optional)
  • Oil-Based Polyurethane (To Seal Oil-Based Paint)

1. Prep Your Workspace

Prep Your Workspace

Before applying the epoxy, you should prep the workspace. Tape the bottom of the walls and doors so the epoxy doesn’t get on them while you are painting the floor. You should also remove all objects and furniture on the floor.

Open all windows and doors for adequate ventilation. Epoxy floor has a very strong chemical odor because of resins in the finish. So, having a good ventilation is a must. If there aren’t enough windows, you should install a fan in the room first.

2. Tape A Large Drop Sheet On The Floor

Tape A Large Drop Sheet On The Floor

Next, check if the floor is dry enough for the epoxy floor to be applied over it. 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 on the floor for 24 hours. Then, lift the drop sheet to check if the underside is wet. If the drop sheet is wet, you shouldn’t put floor epoxy on the floor because the epoxy will not bond well. If it’s a newly painted floor, then the paint needs more time to cure or dry.

However, if the drop sheet’s underside is dry, you can go ahead with the task.

3. Sand The Existing Paint

Sand The Existing Paint

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

To sand, the existing paint, use fine-grit sandpaper. You shouldn’t use coarse sandpaper as it can remove the entire paint. 

If you plan on sanding a large surface area, then sanding manually isn’t an option because it will be time-consuming. Instead, use an orbital sander or floor sander.

After you sand the existing paint, clean the lower parts of the walls and doors to get rid of dust nibs. If you don’t, the dust nibs can fall on the epoxy floor during or after it has been applied.

4. Seal The Paint

Seal The Paint

If you want to put the epoxy floor over oil-based paint, then you need to seal the oil-based paint first. Apply 3 coats of oil-based polyurethane over the oil-based paint to seal the finish. Let the oil-based polyurethane cure before you move on with the task. This will take a few days.

5. Clean The Floor

Clean The Floor

Next, clean the floor. This is important to get rid of any stains on the painted floor. If there are oil-based stains on the floor, use a mild solvent such as rubbing alcohol to remove them. 

Don’t use a solvent that can damage the paint underneath. For example, solvents like mineral spirits and paint thinners can remove the existing paint, so you shouldn’t use them for cleaning.

Related Read: Can You Apply Latex Over Polyurethane?

6. Mix The Epoxy Floor Paint

Mix The Epoxy Floor Paint

Next, mix the epoxy floor. The epoxy floor is a two-part paint that must be mixed correctly to create the epoxy finish.

To do this, you need to follow the manufacturer’s instructions. The usual ratio is to mix equal parts of the epoxy floor resin with the epoxy floor hardener. The resin is epoxy paint, while the hardener is the part that makes the paint strong.

The two-part epoxy should be mixed in the paint container. Stir the paint only if indicated by the manufacturer. After mixing the two parts of epoxy floor, cover the container with the led and wait for 1 hour. This allows all the ingredients to be properly mixed and settled.

If you want the floor to have the same color, you should pick an epoxy paint that matches the floor color and not a clear coat epoxy. A clear cloar epoxy will give you a dull finish, while a colored epoxy will give you a bright and colorful finish. 

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

7. Prime The Floor

Prime The Floor

Priming over a painted surface isn’t very important, but you must do it. The existing paint can serve as a good base for the epoxy floor, but a primer is necessary if the floor has dents or cracks.

These small cracks and holes will suck the epoxy floor finish after it is applied. This will lead to uneven paint application and an amateurish finish. So, if you want a good finish, use a primer to fill and seal the cracks and holes in the floor before applying the epoxy floor finish. 

Use a primer that is compatible with epoxy paint. You need to apply 1-2 coats of primer. 

8. Apply The Epoxy Floor

Apply The Epoxy Floor

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

Here are 5 tips you need to follow when applying epoxy over paint: 

  1. Apply thin coats – You shouldn’t start with heavy coatings because the epoxy will be very difficult to control. Start painting the floor at the edges. This means you should start at the corners of the floor.
  2. Use a small paintbrush for edges – To apply the epoxy floor on the edges use a small brush. If you use a large brush, you can accidentally paint the walls too. After painting the edges, you can use a larger paintbrush for the floor. You can use a foam roller to cover the wider areas of the floor with epoxy.
  3. Use a Paint Shield – Use a paint shield while applying the floor epoxy in tight corners on the floor. The paint shield will prevent you from applying the epoxy on areas you don’t want to. Paint shields keep the epoxy floor finish where it should be used on.
  4. Apply 2 coats of epoxy floor –  You need 2 coats of the epoxy floor for a strong and durable finish. Epoxy flooring takes 24 hours to dry for a re-coat. You need two cans of epoxy resins and hardener. That’s because once the epoxy resin and hardener is mixed, you must use it within 2 hours. So even if you don’t finish the first mixture of the epoxy floor, the leftover epoxy 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 paint sprayer. If you spray the finish, the spray gun will spew resins in the air, these resins shouldn’t be inhaled. So use a foam brush or foam roller.

9. Seal The Epoxy Floor

Seal The Epoxy Floor

After the epoxy floor has cured completely, apply a top coat of sealant. Exterior polyurethane is a good choice. 

Usually, epoxy floor is durable enough without a sealant but for high-traffic floors, it’s advised to seal them. 

When you have completed all these steps, you have successfully applied epoxy floor over the paint.

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 oil-based paint can interfere with the epoxy’s chemical bonding process. 

So, the best paint or base coat to use before applying epoxy floor is latex or water-based paint. Epoxy floors will adhere to latex paints since latex paints have a low level of active chemicals.

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

So, to apply epoxy paint over oil-based paint, you have to seal the oil-based paint first. You can seal it with 3 coats of polyurethane since polyurethane and epoxy floor bond well together.

So, before applying epoxy paint over paint, you need to know the type of paint the floor has. To know what type of paint the floor has, you can use the water test: 

Put a few drops of water on the paint and leave it for a few minutes. If the water turns dark or black, the paint is oil-based. If the water doesn’t change color, the paint is water-based. 

The water will turn black because of the chemicals in the oil paint. These chemicals will also prevent the epoxy floor from adhering to the oil paint.

However, if the water doesn’t change color, then the paint is water-based. The low levels of chemicals in the latex paint will make the epoxy paint stick well to it. 

How Long Does Epoxy Paint Last On Concrete?

Epoxy floor finish lasts between 15 years and 30 years on concrete. On average, epoxy floor paint 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 for the epoxy paint to last on concrete.

The durability of epoxy paint on concrete depends on several factors. Moisture, traffic, and dirt can influence the life of the epoxy paint and the concrete underneath.

For instance, epoxy paint will last longer on a concrete floor in the room than on 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 epoxy finish.

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

Can You Epoxy over Painted Wood?

You can epoxy over painted wood. But, if the wood is painted with oil-based paint, you need to seal the wood first before applying epoxy paint. That’s because epoxy paint won’t stick to oil-based paint.

However, if the wood is painted with water-based paint, you don’t have to seal the wood. You just need to clean the surface, mix the epoxy, and apply it over the painted wood. 

Final Words

Overall, you can apply an epoxy floor over a painted floor. The paint should be clean and well sanded. But if you are painting over oil-based paint, you will need to seal the paint with a top coat before applying epoxy floor over it.

Water-based and acrylic paints don’t require a sealant. You just need to clean, sand, and prime the paint. Then you are ready to apply epoxy floor over it.

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