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E-Coat Masking Tips to Avoid Costly Errors

E-Coat Masking Tips to Avoid Costly Errors

Can Electrocoat be Masked like Powder Coating and Paint?

Yes, electrocoat can be masked, just like powder coating and painting. Masking is a common practice in industrial coating, used to protect certain areas of a part from being coated.

Areas that might require masking include:

  • Threaded areas: coating a threaded area can make it difficult or impossible to add the part to its intended sub-assembly.
  • Machined surfaces: coating a machines surface can affect its fit or function, as these surfaces often have tight tolerances that require a precision fit.
  • Bearing surfaces: Bearing surfaces need to be free from any coating buildup to ensure proper function.
  • Electrical contact points: Some parts have contact points that require a bare metal surface to maintain electrical connectivity and cannot be coated.
  • Critical functional areas: Critical functional areas of a part, such as seal surfaces or mating surfaces, may require precise fit and performance. Masking these areas prevents coating buildup and ensures their proper function.

Masking can be done using a variety of materials such as tape, plugs, caps, and covers. Your masking materials should be carefully selected to ensure they can withstand the electrocoating process without degrading or melting. Additionally, proper masking techniques and equipment should be used to ensure the mask stays in place during the electrocoating process and is removed cleanly afterward without leaving any residue or damaging the coated surface.

To learn more about how Great Dane can become a partner in e-coating your  parts and products, call us at 724-537-9709 or visit our Contact Us page.

Types of Defects with Improper Masking

At a glance, electrocoating looks like a simple immersion coating system, followed by curing in an oven.

The part is immersed in a coating bath containing a water-based paint or resin. The bath is charged with an electrical current, creating a positively charged anode and a negatively charged cathode (the part). The e-coat is deposited evenly due to the electrical attraction between the part and the anode, and coating thickness can be controlled by varying the electrical current.

It’s important to note that masking can affect the electrocoating process by altering the electrical charge distribution on the part. This can result in an uneven coating thickness or coverage in areas adjacent to the mask. Therefore, it’s essential to ensure that masking is done correctly and that the electrocoating process is carefully controlled to achieve the desired coating quality and performance.

Other types of defects include:

  • Runs and drips: Coating material can build up along the edges of the mask or in the gaps between masking materials, resulting in runs and drips on the part surface
  • Cracking and peeling: If the mask is not removed correctly, it can cause the coating to crack or peel.
  • Uneven coverage: Improper masking can result in uneven coating coverage on the part.
  • Coating buildup: If the mask is not applied properly or if it is not removed completely, it can cause a buildup of coating material on the surface of the part.
  • Masking material residue: If the masking material used is not suitable for the electrocoating process, it can melt or leave a residue on the part after removal.

Tips on Avoiding Masking Errors in Electrocoating

The first step is to choose the appropriate masking material that is right for both the part and the electrocoating process. The masking material should be able to withstand immersion and oven curing without degrading or melting.

Proper surface preparation is essential to ensure that the masking material adheres to the part correctly. The surface should be clean and free of contaminants, such as oil, grease, or rust.

Whether applying tape, a plug, or cap, the masking material must be carefully applied and firmly attached. For example, you wouldn’t want any air bubbles under tape masking. The same care is to be taken in removing the masking, using the appropriate tools and techniques (without damaging the coating or leaving residue behind).

When using masking tape on die cuts, use high-temperature masking tapes. Make sure the surface has been cleaned or pre-treated (according to the needs of the material), and wear gloves during the application of the masking tape, to avoid contaminating the surface with oil from your hands. Apply pressure with a squeegee or roller to get a secure seal with the metal surface and to prevent leakage.

When masked parts are submerged and then baked, and masking caps or plugs are being used, pressure can build up. This can cause cap or plug blowouts. Vented caps & plugs can help resolve blowouts.

A relatively new innovation is expandable caps and plugs. These combine high-temperature resistant plastic with silicone rubber in a way that expands to seal the metal from having any e-coat leak in, while also preventing blowouts. While more expensive to use, the reduction in errors and rejection rate can make the use of expandable caps worthwhile.

In all cases, test and monitor the masking process. Leave nothing to chance, so that when a full run of racked parts is put through the setup, there are no surprises.

Delivering Excellence in Electrocoating

When you choose Great Dane as your electrocoating partner, we deliver the advantages of e-coating:

Advantages to e-coating include:

  • Enhanced corrosion protection
  • Improved edge protection
  • Lower cure temperature
  • Compliant with global environmental standards
  • Smoother finish

When it comes to industrial coatings, electrocoating is among the most cost-effective, durable, and environmentally friendly coating technologies available.

At Great Dane, our experience includes service for the HVAC industry, Manufacturing and Fabrication, Automotive, Appliances, Construction, Military, Medical, and more.

To learn more about how Great Dane can become a partner in e-coating your  parts and products, call us at 724-537-9709 or visit our Contact Us page.

Over 29 Years of Parts Coating Excellence

At Great Dane Powder Coating, Inc., we have more than a quarter century of experience under our belts. We offer the benefits of a cutting-edge facility and high-end equipment for providing exceptional results.

It’s no wonder that we are trusted by fabrication facilities and manufactures across the country to deliver highly durable coatings on a wide variety of parts and components.

When you want affordable, reliable, and outstanding results, give us a call at 724-537-9709 or visit our NEW ELECTROCOATING CUSTOMERS page today.



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