GSDO Program Hexavalent Chrome Alternatives: Final Pretreatments Test Report

Hexavalent chrome free pretreatments should be considered for use on Ground Support Equipment (OSE) and Electrical Ground
Support Equipment (EOSE). Both of the hexavalent chrome free pretreatments (Metalast TCP HF and SurTec 650C) evaluated by
this project met, and in some instances exceeded, the requirements ofMIL-DTL-5541 "Chemical Conversion Coatings on
Aluminum and Aluminum Alloys". For DC resistance measurements, both Metalast TCP HF and SurTec (!50C met initial
requirements following assembly and in many cases continued to maintain passing readings for the duration of testing.