Some car detailers use epoxy primer as a sealer. And it does an outstanding job at sealing the metal beneath from corrosion.
If you want a more uniform finish, you may consider painting over it. For those who have never done this before, you may be wondering, is it okay to paint over epoxy primer?
You can paint over epoxy primer as long as it’s still fresh and hasn’t fully cured on the surface. When it’s still fresh, paint can be absorbed easily and will hold on for longer.
Therefore, if you are sealing your car with epoxy primer, you can paint over it as long as you do it before it fully dries.
Table of Contents
- What is Epoxy Primer?
- Epoxy vs. Etch Primers
- Can I Paint Over Epoxy Primer?
- Does Applying Paint Too Late Cause Adhesion Issues?
- Can I Paint Directly Over Cured Epoxy Primer?
- Does Brand Matter When Painting Over Epoxy Primer?
- What is the Prep Work Involved in Painting over Epoxy Primer?
- Can I Spray Etch Primer over Epoxy Primer?
- What Type of Paint Can You Use over Epoxy Primer?
- Is It Advisable to Clear Coat Epoxy Primer?
- Can I Mix Paint with Epoxy?
- Is Epoxy Primer a Sealer?
- How Long Does Epoxy Primer Take to Dry?
- Is Epoxy Primer Waterproof?
What is Epoxy Primer?
To easily understand why it is okay to paint over epoxy primer, we must define what it is and compare if it’s different from the regular primer.
When it comes to painting, we all know that primer goes first. This ensures the final finish features a richer color. But is it the same case with epoxy primer? Let’s find out.
Epoxy primer is a sealer that features a non-porous finish. When it comes to the painting of steel, epoxy primer always goes first followed by paint. It can also be used on other surfaces such as plastic and fiberglass.
Epoxy primers are known for having strong adhesion and are quite durable. Therefore, if you have some on your car surface, rest assured the surface beneath is well protected.
From a chemical composition perspective, epoxy primer is made up of carbon chains linked to oxygen, nitrogen, and hydrogen. Because of its strong chemical buildup, epoxy primers prevent metal oxidation.
This is possible because epoxy primers are non-porous. Therefore they do not allow air or liquid to pass through.
Epoxy vs. Etch Primers
Before we can go back to whether you can paint over epoxy primer, let us compare it to etch primers. The latter is ideal when painting car metal surfaces that require a quick turnaround time.
The role of etching primers is to create a finish that can bond easily with paint. On the other hand, epoxy primers contribute more to preventing corrosion and oxidation.
Epoxy primers are not to be sanded, and if you must, only use fine sandpaper. They are more of a sealant and are designed to keep contaminants away.
Can I Paint Over Epoxy Primer?
When defining epoxy primers above, we mentioned how they have excellent adhesion properties. Other than sticking to metal, epoxy primers can easily be painted over. As long as you don’t take too long.
Remember, different sealant and paint manufacturers have varying requirements on how their products should be used.
In most cases, after applying an epoxy primer, you have a seven-day window to paint over it, apply a topcoat, or anything else you are interested in.
If it has been more than a week, you may have to scuff the primer before applying some fresh paint over it. It is important to confirm with your manufacturer first before doing anything else.
Does Applying Paint Too Late Cause Adhesion Issues?
Even though you can paint over epoxy primer, there are certain requirements you have to meet. First, you can’t paint it too late, and neither can you do it too soon.
If you take a couple of days to paint over epoxy primer, without a doubt, you will run into some issues mostly related to adhesion.
The epoxy will have dried up, and because it is non-porous, it won’t let the liquid in the paint absorb into it. As a result, the paint won’t hold up for long and will chip or peel after a couple of months.
There is also another risk of painting over epoxy primer too soon. When you do that, you may compromise the gloss.
Ensure that you read the manufacturer’s instructions on when the right time to paint over epoxy primer is. Ideally, it should be anywhere from 24 to 72 hours.
Can I Paint Directly Over Cured Epoxy Primer?
It’s not advisable to do this. Cured epoxy primer may cause adhesion problems when painted directly over. The best course of action is to scuff the epoxy primer and then sand it.
Does Brand Matter When Painting Over Epoxy Primer?
Even though the paint is compatible with epoxy primers, we advise you to stick to only one type of brand. Using paint and primer from the same brand increases the chances of ensuring the two blend well.
If you go with different brands of the two products, there may be compatibility issues, and somewhere along the line, the paint will peel off.
What is the Prep Work Involved in Painting over Epoxy Primer?
Any paint job on your car will need some prep work, even painting over epoxy primer. The main preparation needed is to scuff the epoxy primer if it has been sitting there for a while.
If the epoxy is still fresh, you don’t have to worry about prep work. Just clean the surface and spray directly. But if it has been like that for a while, you will need to grab a scuffing tool and get to work.
Some car owners use sandpaper. It doesn’t matter as long as you scuff the epoxy primer first.
The other alternative is to spray a thin layer of epoxy before spraying some paint. This will ensure the epoxy is still fresh and can blend well with the new paint.
For you to use this alternative, you must know what epoxy primer was used initially. If you don’t know, you must scrap it off.
When you go ahead and use the wrong product, there is a good chance that it won’t be compatible, and the finish may not last long, or it may look terrible.
Can I Spray Etch Primer over Epoxy Primer?
We have already looked at the differences between these two. Spraying etch primer over epoxy primer will make no sense since etch primer is designed to anchor itself to metal.
If you want to use etch primer on your car, strip off the old epoxy primer first before applying it. This is because you can’t have both.
What Type of Paint Can You Use over Epoxy Primer?
You can paint over epoxy using both water and oil-based paints. What matters most is that you stick to the same brand.
Please be careful with oil-based paints since they are known to leave an amber hue on epoxy primer. As you choose which type of paint to apply over epoxy primer, there is one thing that you need to get right.
Paint sticks perfectly on fresh epoxy primer, not epoxy that is yet to dry or harden.
This is a mistake that many DIY detailers make. The epoxy primer must dry first before applying paint. Depending on the epoxy primer manufacturer you are dealing with, they will recommend the drying window.
Follow their instructions, and the results should be more than pleasant.
Is It Advisable to Clear Coat Epoxy Primer?
Should you be interested in applying lighter paint such as clear, feel free to go right ahead. Other than paint, epoxy primer also blends well with a clear coat.
The clear will enhance the finish of the primer. At the same time, it will also protect epoxy primer.
Can I Mix Paint with Epoxy?
You may think that doing this will result in killing two birds with one stone, but you will have taken yourself two steps back.
Here is the thing, epoxy and paint do not mix. We are talking about all types of paint, ranging from oil to water-based paints.
Is Epoxy Primer a Sealer?
Even though you can still apply a sealer followed by an epoxy primer, you can still use epoxy primer as a sealer. Due to its characteristics, epoxy primer seals metal from contaminants, water, and air.
When applied to a car, an epoxy sealer ensures the surface is impenetrable. Therefore, even if the paint peels or chips off, the car will be in excellent condition since it will be well protected.
How Long Does Epoxy Primer Take to Dry?
The manufacturer of that epoxy primer should state that clearly in their product label. However, for general knowledge, most epoxy primers dry within 3 to 6 hours.
It can take up to 72 hours for them to fully cure on the surface of your car. The weather heavily dictates how soon an epoxy primer takes to dry. If it’s hot, it dries faster. But, if it’s cold and humid, it will take much longer to dry.
Is Epoxy Primer Waterproof?
Epoxy primer is non-porous, and therefore it won’t let water make contact with metal. The advantage of this characteristic is that your car will be corrosion-free.
On the other hand, this non-porosity of epoxy primer makes it harder to adhere to certain types of paints. It’s, therefore, an advantage and a disadvantage.
It’s also worth noting that this non-porosity makes epoxy primer better than an ordinary primer, which absorbs moisture.