Lamination Refurbishment

Lamination Refurbishment takes an existing part and brings it back into operative condition. This is one of the methods we provide to save our customers money.

C5 coating is used on electrical steels to reduce eddy current heat losses in electric machines. C5 coating is suggested for use where superior insulation is required after stress relief anneal. It provides a uniform, high-resistance insulation for the more severe requirements of large electric machines. In addition, C5 coating is not affected by oils, and provides some corrosion resistance.


Polaris can coat new laminations or refurbish existing laminations.

Lamination refurbishment is a three step process.
  1. The laminations are wet sanded on both sides to remove any corrosion or oxidation.
  2. C5 coating is applied to both sides of the laminations
  3. The laminations are oven cured.

Process for C5 Coating


We have 2 types of C5 coating in stock:
C5 regular and C5 dark grey.
Other coatings such as C6 are also available.

  1. Parts can be coated on one side or both sides.
  2. Parts are oven cured per the coating manufacturer's specifications.
  3. We perform Franklin testing per ASTM A717.
  4. We also perform lamination factor testing per ASTM A719.

Polaris can control the thickness of the coating for each lamination down to 1 micron thickness per side.

Once a lamination is coated, you will notice a change in the "tint" of the material. Uncoated material has a "silver" tone whereas C5 regular coated material has a "gold" tone.


Our New C5 Dark Grey coating is now in stock! For those who want a more "factory" finish to their C5 coating, our C5 Dark Grey is the answer.






If your laminations are too damaged to be recoated, they can be replaced with new laminations. Our expert in house staff will help you find the right solution.

Visit our Reverse Engineering page for more details.

Franklin Testing

Our parts are Franklin tested per ASTM A717.

Franklin testing consists of running a current through the metal to check its resistivity. As you may already know, copper is a good conductor. An uncoated lamination is also a good conductor. Once laminations are coated with our C5 coating, there is a drastic improvement in resistivity.

Read more