What are Wash Primers?

Put simply; a wash primer is a synthetic product that normally contains phosphoric acid or zinc chromate. It is applied as the first coat on metal surfaces. 

The primer normally has anti-oxidation and anti-corrosive elements. 

This means that once the primer dries, the metal surface is protected, and a layer of paint can be applied over the primer. 

The goal of the wash primer is to make the entire painting process go faster and more efficiently while protecting the metal itself from rust and other corrosive properties. 

Any metal surface that is vulnerable to corrosion should have a layer of protection as provided by the wash primer. 

Application Method

To apply a wash primer to the metal surface, you will need to do the following. 

1- Clean: Make sure that the surface has been thoroughly cleaned and degreased. You may use a pressure washer or steam cleaner with the proper detergents. 

Be sure to thoroughly rinse away all the detergent so that no residue is left. Then use a wiping solvent as the final part of the preparation process. 

2- Sand: This only applies to aluminum and anodized parts so that the wash primer will better stick. 

Sand the surface, and this will promote proper adhesion. 

If the anodized aluminum is of architectural grade, then you will need to use 40 to 80 grit sandpaper until you can see the surface profile. 

Then clean and degrease the surface as normal. 

3- Mix: When you mix wash primers, the base will need to be stirred until you get a consistent blend. 

You can mix it by hand, but if you have access to a shaker or power mixer, that is the better option. 

Once you have mixed the wash primers, add the converter and then mix them again so that the consistency and blend are just right. 

And now you are ready to apply the wash primer. Be sure to cover the entire surface and then let it dry. 

Once fully dried, you can add the paint. 

It is generally recommended that you apply two coats of paint, but if the color of the primer matches or closely matches the paint, you may get away with only one coat. 

What Types of Metals are Suitable for Wash Primers?

Any metal surface that is vulnerable to rust or corrosion is a prime candidate for a wash primer. 

The most common types of metals include the following. 

1- Aluminum

2- Brass

3- Galvanized Metals 

4- Stainless Steel

Such primers are used with primers that contain plenty of zinc. They can dry fast and starts the resistance process to oxidation quickly. 

They can be applied in a relatively thin layer if there is a topcoat. In addition, they do not create much of an odor and their recoat time is unlimited. 

However, wash primers are not suitable for wooden or plastic surfaces. 

Wash primers are not essential for painting on metals, but they are desirable as they provide a strong surface for your paint to adhere to. 

Be sure to purchase wash primers that have protection against corrosion or rust. Otherwise, you will need to find additional products that offer that protection.