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Alodine 1500 Versus MIL-C-5541

Is some one can explain me the difference between a finish per MIL-C-5541 class 1a or 3, and Alodine 1500. Thanks for your help.

STUNAULT
electronic components distributor - VIROFLAY, FRANCE
2004

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Alodine is a Henkel trade name for a range of proprietary processes that can be used to apply chromate conversion coatings. Alodine 1500 is one particular formulation.

Mil-C-5541 is the military specification for chromate conversion coatings on aluminum. One of the requirements for compliance with Mil-C-5541 is that only specific pre-tested process formulations can be used. The list of such formulations is given in QPL-81706 [on DLA] where QPL is an acronym for Qualified Products List. In the version of QPL-81706 that I have on file, Alodine 1500 is qualified for Class 3 coatings, i.e., coatings designed for good electrical conductivity. Class 1a is for the heavier coatings which may be used alone or under paint, but for which low electrical resistance is not a requirement.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

How does Aludine 1500 compare to Alochrom 1000? with respect to finish and performance. From what I can see they are both essentially the same. Is it true that the Aludine process requires more stringent controls and testing? Or is the difference simply terminology? I have heard that as a general rule of thumb Alodine is an American term and Alochrom is a U.K. term. Does anyone support this theory?

Andy Brind
Enclosures - Bedford, England
2004

Ed. note: letter 8417 supports that theory, but the trademark owner Henkel would be the authority.

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2006

Does anyone know about the RoHS compliance of such Alodine surface treatment ?

François RAFFIN
- Paris, France

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Is a Ford Thunderbird a 2-seat car (1955), a 4-seater (1958), a 5-seater (1983), or is it back to a 2-seater (2002), Francois? It's whatever Ford decides it is at any given time, because they own the name; they can put that trade name on whatever style car they choose.
Similarly, Alodine is a trade name and there are many different Alodine numbers and formulations. Some older ones are surely hexavalent chromate and thus not RoHS compliant, and some newer one surely are. But only Henkel gets to say which Alodine numbers they are going to assign to RoHS compliant formulations. They are within their rights to decide that a number which was traditionally hexavalent will now be trivalent; so you really need to contact them rather than have a 3rd party give you info that Henkel could decide to change. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey