Switching from hexavalent to trivalent chromating of aluminum

Q. We're considering switching our product-line from chem. film plating IAW mil-c-5541 to a Trivalent, can you tell me the pros cons? The product-line uses AL bars to hold SS cables in place mostly used on US NAVY ships. The more corrosive applications use SS bars but a vast majority are inside but still needs to pass a 7 days salt spray test IAW Mil-c-5541.

June 7, 2012

A. Hi Eric.

The MIL-DTL-5541 approved trivalent chromates will be more environmentally friendly and are designed as replacements, so they should meet your need. The biggest disadvantage is probably that they are invisible or nearly so.

Regards,

Ted Mooney, P.E. RET finishing.com Brick, New Jersey