cleaning magnesium 3

[rubepierre]

what are the no-no's for cleaning this metal???
We imeresed ia piece in out cleaning a
tank and it turned black,,,HELP.....

 

[CoryPad]

If your piece turned black, you probably got a smut from oxidation. In general, you should not acid pickle, but rather you should use alkaline cleaning. ASM Handbook Volume 5: Surface Engineering gives good information acceptable practices. It is available at:

http://www.asminternational.org

 

[TVP]

ASTM has a number of good references with respect to magnesium surface preparation & corrosion:

ASTM D 1732 STANDARD PRACTICE FOR PREPARATION OF MAGNESIUN ALLOY SURFACES FOR PAINTING

ASTM B 879 STANDARD PRACTICE FOR APPLYING NON-ELECTROLYTIC CONVERSION COATINGS ON MAGNESIUM AND MAGNESIUM ALLOYS

ASTM B 480 STANDARD GUIDE FOR PREPARATION OF MAGNESIUM AND MAGNESIUM ALLOYS FOR ELECTROPLATING

B 480 references the standard guide ASTM B 322, which is an excellent reference for all metals

ASTM B322 CLEANING METALS PRIOR TO ELECTROPLATING

ASTM standards can be obtained from ASTM at

http://www.astm.org

or from Global Engineering Documents at

http://global.ihs.com

.

There is a military spec, MIL-M-3171 MAGNESIUM ALLOY, PROCESSES FOR PRETREATMENT AND PREVENTION OF CORROSION ON, that has some information on this subject as well. It has been officially superceded by SAE-AMS-M-3171, but you can still download the last version of this document, free of charge, using ASSIST-Quick Search at

http://assist2.daps.dla.mil/quicksearch/