Magnesium Alloys

[manual]

Well Here I am still working in Ethiopia, someday I may get home.
anyway heres some info. about working with Magnesium.
Maqnesium Alloys
WARNING: KEEP MAGNESIUM PARTICLES AWAY FROM SOURCES OF IGNITION. SMALL
PARTICLES OF MAGNESIUM BURN VERY EASILY. IN SUFFICIENT CONCENTRATION,
THESE SMALL PARTICLES CAN CAUSE AN EXPLOSION.
IF WATER TOUCHES MOLTEN MAGNESIUM, A STEAM EXPLOSION COULD OCCUR.
EXTINGUISH MAGNESIUM FIRES WITH DRY TALC, CALCIUM CARBONATE, SAND, OR
GRAPHITE. APPLY THE POWDER ON THE BURNING METAL TO A DEPTH OF 1/2
INCH OR MORE. DO NOT USE FOAM, WATER, CARBON TETRACHLORIDE, OR
CARBON DIOXIDE.
A. Magnesium alloy looks almost the same as aluminum alloy. For equal volumes
of magnesium and aluminum, the weight of magnesium alloy is approximately
two-thirds the weight of aluminum. To keep the weight of the airplane low,
magnesium alloy is sometimes used.
B. You can cut, drill and ream magnesium alloy with the same tools you use on
steel or brass. The cutting edges of the tool must be sharp.
C. Magnesium alloys must not touch methyl alcohol. Do not use magnesium alloys
in liquid deicing and water injection systems. Do not use magnesium alloys
in the integral fuel tank areas.

 

[manual]

Caution: Do Not Use Carbon Steel Brush Or Steel Wool On Magnesium
Surfaces. Tiny Dissimilar Metal Particles Will Become
Imbedded In The Magnesium Causing Further Corrosion And
Subsequent Damage To Part.
Do Not Use Silicon Carbide Abrasives On Magnesium Surfaces.

 

[manual]

4. Maanesium Alloys - Conversion Coating
A. Magnesium alloys are highly susceptible to corrosion when the metal surface is exposed to the
environment without a protective finish. An oxide-carbonate film will normally form on an
exposed magnesium alloy surface but this film provides very little protection against corrosion.
A proper protective finish is therefore required.
B. All magnesium alloy surfaces that have been reworked must be cleaned and treated with a
conversion coating.
C. Materials Required:
(1) Chromic Acid
(2) Calcium Sulfate
(3) Cheesecloth
(4) Solvent - General Cleaning of Metal (Series 88) (Refer to SOPM 20-30-88)
(5) Sodium Hydroxide
(6) Sulfuric Acid

 

[manual]

D. Prepare the Solution
NOTE: The solution must be prepared and stored in polyethylene or glass container.
(1) Fill a clean polyethylene or glass container to the 9/10 level with distilled water.
(2) Slowly add 1-1/3 fluid ounce (39.5 milliliters) of chromic acid per gallon of final solution.
(3) Add 1 fluid ounce (29.6 milliliters) of calcium sulfate per gallon of final solution.
(4) Fill to final solution level with distilled water.
(5) Stir vigorously for 15 minutes to ensure that the solution is saturated with calcium sulfate.
(6) Let solution stand for 15 minutes to allow undissolved calcium sulfate to settle to the
bottom of the container.
(7) Decant to another polyethylene or glass container without transferring undissolved calcium
sulfate.
(8) Adjust pH with additions of Sodium Hydroxide or Sulfuric Acid to bring within a range of 1.2
to 1.6.
E. Prepare the surface for conversion coating.
(1) Mask all surfaces likely to be affected by running, dripping, or splashing of the solution.
(2) Seal or plug all holes, gaps, and inlets to assemblies containing honeycomb or foam
plastic with suitable sealing or caulking material or rubber plugs to prevent entry of any
solution.
(3) Wipe treatment area with dry clean cheesecloth to remove loose particles and residue.
(4) Wipe with cheesecloth dampened (not saturated) with solvent, Series 88 (Refer to
AMM 20-60-3 and SOPM 20-30-88). Repeat using clean cheesecloth until no visible
residue transfers to the cheescloth.
(5) Allow to dry to a minimum of 15 minutes.
F. Apply the conversion coating
CAUTION: SEVERE RUBBING OF WET SURFACE CAN CAUSE COATING DAMAGE.
(1) Apply solution by swabbing with brush, swab, swatches, cellulose sponge, or white blotting
paper. Maintain a continuous wet film until metal surface becomes dull golden or dark
brown in color. Discard used solution.

 

[manual]

(2) Rinse with cold clean water.
CAUTION: DO NOT DIRECT HIGH PRESSURE AIR TO SURFACE WHILE DRYING
AS COATING IS STILL SOFT.
(3) Allow to dry at ambient temperature. If possible, use low pressure air to dry the surface.
(4) Restore the original finish as soon as possible after drying. Handle parts with clean gloves
and keep parts clean and dry to avoid surface contamination.

 

[manual]

Corrosion Resistant Steel (CRES)
A. Corrosion-resistant-steel (CRES) sheet is used on some parts when high
strength is necessary.
B. CRES must not touch magnesium, aluminum or cadmium. If it does, galvanic
corrosion will occur. To isolate CRES from magnesium and aluminum, apply a
finish that gives protection between their mating surfaces.

 

[Dan Forsh]

I take it you are bored then?

 

[spacemule]

I take it you are bored then?

I'd bet he's been drinking the water over there. . .

 

[Dan Forsh]

I'd bet he's been drinking the water over there. . .

Magnesium poisoning it is then :hmm3grin2orange:

 

[manual]

Well it's night time now and Duty calls.

 

[Urbicide]

Ethiopia? Your last post until today was back on 3/7/08. You said you were going to bed. I thought you passed away in your sleep! So what brand of saw do the Ethiopians prefer?:wave:

 

[billyjoejr]

Wow. :jawdrop:

Now I am worried about the lifespan of my 032 and 361.

Guess I better upgrade to the 290, made from impervious plastic. :jester:


Main Entry: im·per·vi·ous
Pronunciation: \(ˌ)im-ˈpər-vē-əs\
Function: adjective

1 a: not allowing entrance or passage : impenetrable <a coat impervious to rain> b: not capable of being damaged or harmed <a carpet impervious to rough treatment>
2: not capable of being affected or disturbed <impervious to criticism>

 

[rb_in_va]

Well it's night time now and Duty calls.

Are you a pilot on Southern Air?

 

[Lakeside53]

"Southern Air" sounds like another oli' North CIA front...

 

[Urbicide]

I was thinking of "Air America".

 

[Lakeside53]

lololol

Loved those Pilatas Porter landings!

 

[Urbicide]

Hey Manual, are you a Spook? :Eye: :Eye: I promise I won't tell anyone.

 

[2000ssm6]

Hey Manual, are you a Spook? :Eye: :Eye: I promise I won't tell anyone.

"A Spook", LOLOLOLOL

 

[RiverRat2]

Hey Manny good to see you again,,,,

I think???????

LOLOL!!!!!