What is Sacrificial Plating – How it Works and Benefits?

Sacrificial plating, sometimes called sacrificial coating, is a type of coat comprising metal layers that have a lower electrode potential value compared to the metal that they protect. 

Also, they may have a higher level in the electrochemical series. In either case, sacrificial plating creates a clear coating or barrier that protects the surface underneath. 

You can think of it as a protective barrier that slowly corrodes over time but is designed to prevent such corrosion or oxidation to the metal it protects. 

How Does It Work? 

Just as paint protects the materials that make up the walls in your home, so too does sacrificial primer, plating, or coating protect the metals underneath. 

Perhaps the most common type of sacrificial plating or primer is the coating used for galvanized steel, sometimes called zinc-coated steel.

 It is true that the anodic reaction will vary depending on how fast the sacrificial coating dissolves. 

If a primer is made from noble metals that are more active, such as nickel or tin, then it can provide proper protection for as long as the coating lasts. 

When the coating becomes thin enough in any one area, this will allow the oxidation process to begin on the metal itself.

It is especially true with steel that the rust or corrosion can become intense.

When adding in tin, the corrosive process intensifies. This is because tin is cathodic, which means it will quicken the pace of the oxidation of steel. 

Materials Used in Sacrificial Plating

The substances used in this type of plating generally include materials that are considerably cheaper compared to the metal they protect.

Such materials include the following. 

1- Acrylates

2- Biopolymers

3- Clear Polymers

4- Waxes 

The advantage of polymers is that they create a weak bond with the metal, so they can be removed when needed rather easily. 

The other types of plating or protection bond with the metal to a greater degree, meaning that it takes more effort to remove it.

However, waxes may be quite easy to remove, too easy depending on their use. 

The Benefits of Sacrificial Plating Over Other Coats

There are strong benefits to using sacrificial coatings, especially on metals that might be vulnerable to corrosion and either not easy to maintain or to save money. 

Breathable: This may seem counterintuitive at first, but this type of protection allows for some breathability to take place.

The advantage is that any moisture that comes from underneath the metal can evaporate away without being trapped.

The result is less corrosion, not more, as the coating breathes just enough to allow for proper evaporation to take place. 

Clear: This type of sacrificial primer is invisible, so you can add it to the outside, and it will not affect how the surface appears. 

Easy to Apply: If there is one advantage that stands out above the rest, it is that the coating is simple and easy to apply.

This means you spend less time applying it, which saves effort and energy. 

Environmentally Friendly: Because the sacrificial primer is mostly based on water, it is better for the environment as it slowly dissolves.