How to quickly I.D. a part as Magnesium 1

[bointucson]

As a structures mechanic, it is often difficult to identify what fittings, in particular, are made of magnesium,other than the obvious "MAG" stamping on some. What are the quickest methods for identifying a part as such, and what are the proper methods for removal of corrosion and allowable limits for material loss (if any)?

 

[KSshopper]

Well, the company line is you know the part is mag if the drawing tells you it's made from mag. If for some reason you don't have the drawing, an NDT technician should be able to determine the alloy.

I don't think there is anything special about removing corrosion from mag, scotch brite pads for mild corrosion and sanders for heavier stuff. Make sure you do your 20:1 length to depth blend ratio.

The SRM should be consulted to determine allowable limits. If no limits are published, Mic the part and check the drawing. You may show the part still is within drawing tolerance.

 

[bointucson]

since I'm at a repair station, it's often difficult to have the drawings on hand, so your advice about using NDT to determine a parts composition is right on target! Thanks! Is this Phil Condit as in Boeing's Phil Condit?

 

[KnifeKnut]

Finding it's density by dunking it and doing the math?

 

[bointucson]

most often corrsion is light, doing a density test would involve dissasembly time, time=money at a repair station, so the ndt would be our best bet, with a density check a close 2nd.

 

[aviat]

Magnesium and other metals can be determined in the field by acid tests as explained John Schwaner in his book Sky Ranch Engineering Manual or at

http://WWW.sacskyranch.com/metfram.htm

Corrosion pertaining to magnesium is covered in FAA AC43.13-1B amoung other sources.

 

[Grue]

AC 43.13-1b Advisory Circular can be downloaded in pdf format from

http://www.moneypit.net/~pratt/ac43/

Glenn.

http://www.metalbashatorium.com