Interpon Powder Coatings recommends the use of a barrier coat epoxy powder primer (MetaPrep™ Grey EL286A) as an undercoat for all perforated aluminium panels where a commercial Interpon D warranty is required specific to the Environmental Classifications of AS4312.

A higher etch rate does not provide sufficient protection to counter long term issues when components are installed in aggressive atmospheres.

The use of an epoxy barrier primer is required to coat the perforated panels to achieve an adequate film build and protection for the sharp edges. This minimises issues associated with edge pull (reduction of film thickness on sharp edges during the curing process), such as filiform corrosion.

The details outlined below are Interpon’s guide for where Interpon MetaPrep™ Barrier Primeris recommended or mandatory.

Download Technical Bulletin – Perforated Panels 


Environmental Classifications
(as per AS4312)
Environmental Type Perforated Panels
C5-I Heavy Industrial Environment

Interpon MetaPrep™

Mandatory for warranty to apply

(Less than 500 meters from a coast shoreline or aggressive atmosphere)

C5-M Beach Front / Marine
C4 Coastal Environment
C4 Swimming and Leisure Pools /
Light Industrial
C3/T Typical Environment

Interpon MetaPrep™


(not mandatory)

C1 and C2 Non-hazadous Environment