Alodine storage requirements have changed

Mech, Spring, 2004 by Michael Malley

Alodine currently is used in three different forms: Turcoat Liquid Accelagold, MIL-C-81706 (8030-00-823-8039); Touch-N-Prep Coatings, Alodine 1132 SEMPEN (8030-01-460-0246); and a powder that is mixed with distilled water and is the same as Alodine 1201. The storage requirements for these items are critical, and serious problems can occur when stored with other reactive items.

Alodine 1201 has been reclassified as a corrosive in the HMIRS, with a hazard-characteristic code (HCC) of "C1," instead of the current HCC "D3." This product no longer is classified as an oxidizer. The SEMPENs (Alodine 1132) are classified as oxidizers and are identified with HCC "D3."

This change now makes the chemicals incompatible with each other, despite the fact they do the same job. The Navy Environmental and Health Center (NEHC) made these changes and additions to the HMIRS-system website on March 7, 2003. The point of contact at NEHC is Gene Kostinas, DSN 377-0746.

HMC&M supervisors must ensure these types of Alodine are stored separately. If you currently have an MSDS for Alodine 1132 from the manufacturer, I suggest you print a new one from the HMIRS website at www.dlis.dla.mil/hmirs.

Alodine is a chemical-conversion coating used to treat aluminum before a primer coat is applied. In other words, it's a pre-paint treatment. Do not confuse Alodine with AMS-M-3171, Type VI, chromic acid brush-on treatment, which is used on magnesium. They cannot be mixed or used on the other types of metal. Alodine is for aluminum alloys only. Alodine turns the metal surface an iridescent gold or yellow color. Furthermore, Alodine 1132 uses air-drying to treat the metal, but Alodine 1201 immediately must be rinsed with fresh water once the desired surface color is reached. If Alodine 1201 dries on the aluminum alloy surface, it will start to corrode that surface and will turn it a dark brown or black color. This reaction is why it has been reclassified as a corrosive.

This fact also raises another question: Is it OK, now that Alodine 1201 has been reclassified, to store it with other C1 chemicals, such as chemical paint stripper. One stripper, MIL-R-81294, contains methylene chloride, a very nasty chemical. NEHC told me, "Yes." They get paid the big bucks to research this stuff, but, being an old-school airframer who has used both materials, I suggest they be stored separately. Chemical paint stripper should be on hand only if it's being used and should be returned to the CHRIMP center when finished.

Corrosives, oxidizers and flammables must be stored separately (different shelves or compartments). However, some oxidizers and corrosives can't be stored in the same locker. The HCC found in the "Physical/Chemical Properties" section of an HMIRS MSDS provides this detail, but the manufacturer's MSDS normally does not. If you're not sure whether two chemicals should be stored together, ask the base safety and environmental office, contact NEHC, or refer to the compatibility guides located in Chapter 23, Appendices C23-C and C23-F of OPNAVINST 5100.19D.

Chief Malley is a maintenance analyst at the Naval Safety Center.

For more info ...

Refer to the manufacturer's MSDS and label for hazards of chemical paint stripper. You also can check your industrial-hygiene survey and NA 01-1A-509, Chapter 5 for more details.