An Introduction To E-Coating





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From automobiles to everyday hardware, customers today demand higher quality and durability from the products they buy. They expect these products to perform well. They also want the finish to look good and resist corrosion for much longer.

What’s the answer to these demands? E-Coating from Minnesota Industrial Coatings.

What is E-Coating?

E-Coating goes by many names, such as:

E-coating is a high-tech process that was only recently developed in the past fifty years or so. 

Electrocoating is an organic finishing method that uses electrical current to deposit paint onto a single component or assembled product. Electrocoating is used across many industries.

When industry professionals discuss electrocoating, they talk about the complete process of surface preparation, coating application, and paint curing. The electrocoating material is a coating applied to the surface with the aid of an electric current. This current will cause the layer to cover recessed areas and edges completely. It is then baked or heat-cured to convert the material to a hard and durable film. This hard and durable film protects the equipment from the elements. The electrocoating forms a physical and chemical barrier, protecting the covered material.

What Materials Can Be Electrocoated?

  • Aluminum extrusions and castings
  • Brass
  • Chrome plate
  • Cold rolled / hot rolled steel
  • Conductive composites
  • Copper
  • Galvanized steel
  • Iron castings
  • Stainless steel
  • Zinc castings

The Industrial E-Coating Process

The industrial electrocoating process is comprised of four distinct steps:

1.) Pretreatment

The material is cleaned, and phosphate is applied to prepare the surface for the application of the e-coat. This process is essential to achieving the performance requirements desired by the customer. 

2.) Electrocoat Bath

Coatings are then applied to the pretreated metal in an electrocoat bath using precisely calibrated equipment. The e-coat bath consists of 80-90% deionized water and 10-20% paint solids. 

3.) Post-Rinsing

Post-rinsing, which occurs next, enhances the coating’s quality and enables the recovery of excess paint. During the e-coat process, paint is applied to a part using a fixed amount of voltage to achieve the desired film thickness. Once the coating reaches the prescribed thickness, the coating process slows down. As the part exits the bath, paint solids that cling to the surface are rinsed off to maintain application efficiency and aesthetics. This residue material, called “drag out” or “cream coat,” is returned to the tank, enabling the e-coat process to achieve application efficiency rates above 95%.

4.) Heat Curing

After the coated part exits the post-rinse phase, it is placed in a bake oven that cures the paint film to maximize its performance. The minimum bake time is 20 minutes at a temperature of 375°F for most e-coat technologies.

What makes electrocoating unique from other finishing methods is the heat curing in the final step. 

Benefits of E-Coating

1.) Superior Corrosion Resistance

E-coating makes products last longer, protecting the metal underneath the coating. Because of this corrosion resistance, e-coating is good on its own or as a base coat for other finishes.

2.) Better Coverage In Tight Or Hard-To-Reach Areas

Because of how the electrocoating is applied, it’s typically the better option when coating any parts that contain hard-to-reach areas. 

3.) Uniform, Even Coat

When the part being finished is immersed into the liquid, the coating is more evenly and thoroughly distributed than, say, a spray gun application. You can count on no dripping, no pooling, and no gaps.

4.) Better Control of Paint Thickness

This dipping process can also result in a thinner coating than powder coating.

5.) Efficiency

Virtually all unused paint is recovered, leaving almost no waste. Also, most e-coating systems are automated. This automation means that the amount of paint applied to a product can be precisely controlled. This precision results in minimal waste, unlike powder or paint overspray.

6.) Environmentally Friendly

Electrocoating is environmentally friendly. Many manufacturers choose electrocoating because it produces virtually no HAPs (hazardous air pollutants) or VOCs (volatile organic compounds). The process is also RoHS, OSHA, and EPA compliant.

Minnesota Industrial Coatings is unique because it makes extra efforts to ensure environmental friendliness. The waste systems we use for the waste products from the pretreatment process can keep the release of hazardous materials well below the regulatory requirements.

Does Electrocoat Need To Be Top-Coated?

No, not always. In many applications, electrocoat can be considered the “final finish” on a product.

However, electrocoat does not hold up well with UV rays. Thus, using a top coat on any parts that will have UV exposure is an excellent idea. When you pair electrocoating with a topcoat, such as powder coating, it’s an outstanding anti-corrosion primer. These topcoats also allow for a variety of color and gloss options that aren’t easy to create with only electrocoating.

Electrocoated Products

Electrocoated products first made their debut in most homes as parts of cars. Other industries quickly caught on to the revolution and how easy it was to make things last longer with electrocoating. 

Now, you are surrounded by electro-coated products in your home and business, and you may not even know it. Some of the most popular products surrounding you every day are:

  • Eyewear frames
  • Giftware 
  • Hardware 
  • Home Appliances
  • Household or business appliances
  • Jewelry 
  • Sporting equipment

Where Are E-Coated Products Used?

The process of e-coating is used for a wide variety of metallic products. Wherever there is a need for exceptional coating performance over a metal substrate, you may find electrocoating used as a primer or as a finished coating. 

But some industries that regularly use electrocoating include:

  • Aerospace manufacturers
  • Agriculture & agricultural equipment
  • Appliance manufacturers
  • Automobile and automotive parts
  • Fasteners 
  • Fixtures 
  • Lawn & garden equipment & furniture
  • Marine & marine components
  • Metal office furniture
  • Transformers 
  • Trim appliances
  • …& many more industries

Do you have a finishing project, and you are interested in learning more about e-coating? Contact Minnesota Industrial Coatings to submit an RFQ.

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