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1K Coating vs. 2K Coatings

There is often confusion and misuse of terms when it comes to describing automotive coatings. Here are some brief definitions that we hope will dispel the confusion.

NOTE: Typically the term "catalyst" is used separately from the terms "activator" and "hardener" (as in epoxy catalyst) because a catalyst does not have isocyanates.

1K: This is a term used to describe a coating that does not require a hardener, catalyst or activator. For example, this term can be used to describe “single-component” paints and all of the aerosol paints we sell (with the exception of the Spray Max products). NOTE: You may have seen “1K” and “Single-Stage” used interchangeably. See definition of “Single-Stage” below.

2K: This describes a coating that needs to be mixed with a hardener, catalyst or activator. This can be used to describe our Eastwood finishes, “two-component” paints and other urethane finishes.

One/Single-Stage: Used to describe a coating that does not require a clear top coat. A single-stage coating may or may not require a catalyst, hardener or activator. Plus, a clear top coat may be added in many cases for enhanced durability or depth.

Two-Stage: Describes a coating system that requires both base and clear coats. This is more commonly referred to as "basecoat/clearcoat" or "BC/CC". The coats of base and clear may or may not require a catalyst, hardener or activator.