Does Primer Sealer Need To Be Sanded? (Explained)

There are a lot of painting techniques out there. Some people sand over sealer, and others don’t. If you plan to start a painting project, coming across such contradicting information can leave you confused. We are here to clarify whether the primer sealer needs to be sanded or not.

Let’s Start by Looking at What are Primer Sealers?

Sealers can be used instead of primers. Alternatively, they can be used before primers. Just from what the name suggests, primer-sealers are formulated to seal off the porosity of a surface.

They are also designed to promote adhesion between the surface and the topcoats that will be sprayed after.

From the above definition of what sealers are, it may seem to be similar to a primer. That is true, but only to some extent.

Sealers can recondition old surfaces that are not considered ideal for painting.

This is one of the perks sealers have over primers. Other than that, did you know that sealer can be used between incompatible finishing coats?

Yes, if you are planning to coat over another finish, you can use sealer in between. Now that you know what a primary sealer is let us look at whether one can sand over it.

Can You Sand Over the Primer Sealer?

Primer sealer is not meant to be sanded. As long as it has been applied correctly and given time to cure, it would be best if you did not sand over the primer-sealer.

The only exception when you can sand over primer sealer is if you notice imperfections after it cures. You can use fine-grit sandpaper to remove any blemishes in such a situation.

After sanding, we recommend touching the sanded surfaces with a coat of sealer. This is to ensure the sealer is intact.

Will the Finish Look Dull If I Don’t Sand Sealer?

Understandably, many DIY painters are tempted to sand after every coat so that they can get a smoother and shinier finish. Well, that is not the case with sealer.

Unlike primer, if sanded, a sealer may not do its job to perfection. This is why we discourage people from sanding over sealer.

You don’t have to worry about getting a dull finish. That won’t happen when you sand after primer and in between coats.

The bottom line is, not sanding over the sealer does not affect the final finish.

But if you do sand over the sealer, you weaken the sealer.

Is Primer Sealer Necessary?

At the beginning of this article, we mentioned that everyone has their painting technique. Some may use sealers, and others don’t see the need.

Unless you are reconditioning an old surface or painting between incompatible finishes, you can move on and use a primer. Most people go with primer, and unlike sealer, you can sand after applying primer.

We can say that sealer is only necessary if your painting project features the above conditions. If it’s an ordinary paint job, feel free to start with primer, sanding, and application of topcoats.

Should I Use Sealer or Primer First?

In our definition of sealer, we mentioned that it could be used as a substitute for primer or before it. If you want to use both primer and sealer, the latter should go first.

When you use sealer first, it will facilitate better adhesion between the substrate and the primer. If you add primer on top of it, make sure you give each coat enough time to dry. Once the primer has dried, you can sand it lightly.

Can I Sand Over the Primer?

At times, it can get confusing on what needs to be sanded and what doesn’t. The sealer should not be sanded. We have already made that very clear. However, a primer must be sanded before spraying paint over it.

If you want a beautiful finish, you should always sand over primer. Sanding primer smoothens the surface and creates the ideal environment for the paint to adhere to.

Other than the primer, you should also sand in between topcoats.

All this ensures the final finish looks fantastic. It is advisable to give the primer a few minutes to dry before sanding and painting over it.

Should I Wet Sand or Dry Sand Primer?

Whenever you want to sand a painted surface, you should always go for wet sanding. Unlike dry sanding, wet sanding is less abrasive.

This means that it won’t scuff off a lot of the primer from the surface. Wet sanding does a commendable job of smoothening a surface while keeping the primer intact.

Is It Okay to Wet Sand Over Sealer?

After reading that wet sanding is less abrasive, you may be wondering if it is okay to wet sand over sealer. We are still going to remain firm with our advice.

Primer sealer is best left alone. These conditions make a lot of people go for primer directly instead of sealer. You can wet sand over primer and in between coats so that the final finish can look flawless.

Alternatively, if you want to sand immediately after applying the undercoat, you should use a primer.

Is It Recommended to Paint Directly Over the Sealer?

Sure, you can paint directly over the sealer. But remember, in painting, shortcuts are never allowed. If you skip primer, your finish won’t look as good as it should have. Therefore, apply sealer, then primer, sand, and spray a topcoat.

Before we can move on from painting over sealer, there are a couple of things you need to take note of. Sealers should be given enough time to cure before being painted over.

Sealer cures in around 12 hours.

Therefore, if you are applying two coats of sealer, give each coat twelve hours to dry. How hot or cold it is can determine the duration sealer takes to dry.

Always confirm the manufacturer’s requirements.

If you paint over the sealer too soon or too later, you may run into issues later on.

Should Sealer Be Smooth Before Painting?

Not at all. This is another reason why you shouldn’t sand over sealer. For the paint to hold on to the sealer, the surface should have a slightly rough texture, making it easier for the paint to adhere to.

Even if you have applied primer on the sealer, do not over-sand it. Leave behind some tiny grooves that will promote paint adhesion.

When choosing what type of sandpaper to use on primer, go for 500 to 800 grit sandpaper. These are neither too rough to scuff everything out nor too soft to have you spend the entire day trying to smooth out the primer.

Remember, primer can only go for 30 days without paint. Ensure you apply a top coat within a month.

How Do I Get a Smooth Finish Without Sanding Sealer?

Even though sealer contributes significantly to the final finish, declining to sand doesn’t mean that you won’t get a smooth finish. Other factors can help you get your desired finish.

The first thing you have to do is ensure you invest in quality paint, primers, and sealers. If you use anything of low quality in your painting job, there is a good chance that the final finish won’t be as pleasant.

The other thing is that you have to sand in between coats. This will ensure the paint I smooth and shiny. The only exception to sanding is on the sealer.

How is a Sealer Different from an Undercoat?

One can easily confuse a sealer for an undercoat. However, these two products have varying applications. An undercoat should be used on new surfaces.

However, a sealer can be used on surfaces that have already been painted on. And sealers can be used as a substitute for primers.

Is Sanding Generally Bad?

Just because we are saying sealer should not be sanded doesn’t mean sanding is terrible for painting. It is the exact opposite.

Sanding is a critical step in painting only that it doesn’t apply to sealers. If you don’t sand a car during painting, it will look rough and blotchy. Sanding ensures a smoother finish once you are done painting.

It is important when painting a vehicle to know when to and not to sand. If you sand in the wrong step, for instance, after applying a sealer, the results may not be so pleasant.

Therefore, before beginning any paint job, go through a guide on how to paint. There you will know when it’s the right time to sand.

Does the sealer have to Cover the Entire Painting Surface?

Not really. The first few painting steps don’t usually require a lot of precision. That is, you don’t have to cover the entire painting surface as long as the sealer has sealed any unwanted finishes or textures.

You can go ahead and primer over it. Even though the sealer doesn’t have to cover the entire surface, you should ensure that it doesn’t look uneven and there are no drips.

In short, even if the sealer doesn’t have to look perfect, it should be presentable. However, the topcoats have to cover the entire painting surface. They should also be even.