How To Clean Metal Before Painting

Before painting any surface, especially metal, you need to clean and prepare it very well. If the surface is not clean and dry enough, the paint will not stick. So, how do you prepare metal before painting?

Before painting, the cleaning process of a metal surface involves getting rid of every grease, dirt, rust, or old paint on the metal surface. Use a scraping tool, such as sandpaper to remove any deposit on the surface of the metal. After cleaning it thoroughly, you should fill any dents, cracks, or holes on the metal surface. Finally, you have to prime the metal surface before applying the paint.

How To Clean Metal Before Painting

In this article, I will explain how to clean and prepare metal before painting. I will also tell you the best, safest cleaning agents and materials for cleaning metal before painting. Read on to find out more.

Steps for Cleaning Metal before Painting:

Preparing a metal surface for painting is simple but tricky. 

If you do not know how to clean the surface thoroughly, you might not like the outcome after painting.

To ensure you do a great job, you need to use the proper technique and materials to lean the metal surface.

Here is a detailed guide on how to clean metal before painting.

1. Eliminate Dust and Dirt from the Surface

The first step to preparing a metal surface for painting is getting rid of dirt and dust on the surface.

Whether the metal surface is rusty or clean, you should not skip this step.

Before applying any cleaning agent or solvent, you want to ensure the surface is dirt- and dust-free.

You can use a towel, piece of cloth, or sturdy brush to clean the surface.

The initial stage of the cleaning does not require any mineral spirit.

You also do not have to make it perfect yet.

Use the soft brush to remove the spider webs, dust, and dirt on the metal surface.

After that, dip the piece of cloth or towel in water, squeeze, and use it to remove the leftover dust and dirt on the surface.

2. Remove Peeling or Loose Paint

If you are applying new paint on a previously painted metal surface, you need to remove any peeling or loose paint before applying the fresh paint.

However, if the old paint is not bubbling or peeling off, you can leave it the way it is and move to the next step.

There are several ways to get rid of loose or peeling paint on metal surfaces, including scraping, hand wire brushing, and sanding.

Those are highly effective manual methods for freeing a metal surface from loose or bubbling paint.

Nevertheless, some professionals use power tools for this process, as those manual methods are time-consuming and labor-intensive.

If you want to use a power tool, be careful not to damage the metal underneath, as this can result in paint-adhesion issues.

You also need to be cautious when using a wire brush. After brushing it, sand the surface gently with fine-grit sandpaper.

Removing loose and peeling paint would leave dust on the metal surface, so you would have to remove the dust again.

3. Use Mineral Spirits on the Metal Surface

This is another vital, mandatory process of preparing a metal surface for painting.

Even if the metal is free of dust, dirt, or loose paint, you should clean the surface with mineral spirits.

This step also comes before applying any primer on the surface.

Pour some mineral spirits on a towel or piece of cloth and wipe the metal with it.

After this process, the surface would be free of grease and oil.

If there is a lot of grease on the surface, get a new towel, apply more mineral spirits, and wipe it again.

Rust reformers also come in handy at this stage, as they help to stop the formation of rust beneath the paint coat.

Hence, I recommend you use a rust reformer.

Some primers are already formulated to prevent rust formation underneath the paint coat.

However, you should use a rust reformer to be on the safe side.

4. Prime the Metal Surface

If you would expose the metal you want to paint to moisture, you should take this step seriously.

Regardless of where you want to use the metal, applying the right primer to the metal before painting is essential.

Another thing that is as important as priming the surface is choosing the right primer.

When choosing a primer, consider the type of metal you want to coat, environmental conditions, desired performance, and appearance.

Avoid using water-based primers on metal, as moisture can affect the paint and cause it to fall off within months of applying it.

I recommend using galvanized primers, iron oxide primers, and rust-inhibiting primers, as they are more efficient and suitable for metal.

Apply the primer after cleaning the surface to prevent dust accumulation and flash rusting.

The primer will prepare the surface for application and even enhance the adhesiveness of the metal paint.

5. Apply Your Paint

There you go! You can now apply your metal paint without any fear of it falling off or peeling in the near future.

Provided you follow the steps listed above, your paint will stick to the metal surface quickly and efficiently.

For the best result, make sure you use high-quality paint for the job.

Must I Clean a Metal Before Painting?

You can paint metal without cleaning it first.

However, you might not like the outcome of the painting when you are done.

If you want a stunning result, you need to clean it thoroughly before painting it.

Even if the metal appears clean, you should clean it, as any dirt, grease, rust, or dirt on it can prevent the paint from sticking to the surface properly.

Follow the steps listed above to prepare your metal before painting.

Can I Use Vinegar to Clean Metal?

Vinegar has some acidic properties that can help eliminate dust, dirt, and grease on metal surfaces.

However, the secret to using this solution is the mixture.

The ratio of water to vinegar should be 5:1. You can use a piece of cloth or towel for the cleaning.

Can I Clean Metal with Acetone before Painting?

Yes, you can use acetone to clean metal before painting it.

In fact, acetone is one of the major substances you should use to clean metal and other surfaces before painting.

Soak a rag or towel in acetone and wipe the surface with it.


Regardless of the metal surface you want to paint, whether it is a gate, door, protector, etc., cleaning it before painting is very important.

Make sure the surface is free of grease, dust, and dirt.

If there are peeling or loose paints on the surface, use a bristle brush or power tool to remove them, and use fine-grit sandpaper to finish the surface.

Clean the surface with mineral spirits and apply a primer before painting.

Cheers, tools owners!

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Hi there! My name is Jack and I write for ToolsOwner. I have a passion for everything related to tools and DIY projects around the house. You often find me in my workshop working on new projects.