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Unistrut Finish - Perma-Green® III (GR)
Learn about our new corrosion-resistant product line, Unistrut Defender!

Perma-Green® III (GR)

Technical Data:
  • Steel Substrate Preparation: Ten stage continuous cleaning, phosphate process. Substrate after “prep”: sealed zinc phosphate conversion coating.

  • Coating: Thermoset acrylic

  • Color: Federal Highway Green Color Tolerance Chart PR Color No. 4

  • 2H.

  • Coating Process: Cathodic Electrodeposition.

  • Salt Spray:
    - Scribed: exceeds 400 hours per ASTM B117. (1/8" creep)
    - Unscribed: exceeds 600 hours per ASTM B117. (6% red rust)

  • Chalk: Nominal at 1,000 hours per weatherometer G-23 test.

  • Checking:None at 1,000 hours per weatherometer G-23 test.

  • Fade: Less than 50% compared to standard epoxy E.C. coatings.

Environmental Issues:
  • Formulated as a “heavy metal”-free coating (trace elements only).

  • Outgassing in service: essentially none at 350°F for 24 hours.


The performance of Unistrut’s Perma-Green III far exceeds that of conventional finishes. And compared to competitive “high-performance” coatings, Perma-Green III provides superior resistance to chalking, checking and fading and is far less vulnerable to common acidic atmospheres, solvents and alkalis. Just as important, Perma-Green III is the result of an environmentally neutral process that virtually eliminates the toxic metals commonly found in competitive paint-based finishes.

Unistrut Perma-Green III is a factory applied, electro-deposition acrylic coating with superior rust protection and fade-resistance. The acrylic coating is a proprietary formulation and is essentially “heavy-metal” free. The electrodeposition coating process provides a smooth, hard, durable surface which is completely cured. This inhibits introduction of airborne contaminates which can adversely affect sensitive manufacturing environments.

Before the electrodeposition acrylic coating is applied, Unistrut channel is thoroughly cleaned and coated with an zinc phosphate conversion coating. Unistrut’s unique, custom-designed “prep” process consists of ten separate steps, the most thorough in the industry. The cleaning, phosphating and electrodeposition coating processes are continuous and, unlike “batch” processing, result in a uniform quality coating.

Production samples are tested on a continuous basis for corrosion resistance. Unistrut Perma-Green III exceeds 400 hours salt spray (1/8" creep from scribe) when tested to ASTM B117. Unscribed samples exceed 600 hours salt spray. (6% red rust)