MIL-L-24131 Lubricant, Colloidal Graphite In IsopropanolThis specification covers a noncorrosive, dry, adherent lubricant consisting of a colloidal dispersion of graphite in isopropanol, intended for use with metal parts having limited clearance in applications where control of impurities is required.

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MIL-L-24131C(SH)

water and pour slowly into the zirconyl solution.  The resulting solution, after mixing, clears after standing for a few minutes.  (At this point, do not dilute.)

Add solution A to solution B, dilute to 1 liter, and mix thoroughly.

(2)        Standard.  (1.0 ml - 0.01 milligram (mg) F) Dissolve 0.221g of sodium fluoride (NaF) in water and dilute to 1.0 liter.  Dilute 100 ml of this solution to 1.0 liter with water.  Store in a polyethylene bottle.

(c)    Procedure.

(1)        Fuse 2.5g of solids with 10g of sodium carbonate at 1650°F for 2 hours in a platinum crucible.  Dissolve the melt in about 200 ml of water.  Filter through Whatman No. 31 filter paper.  Add 9 ml of 1:1 H2S04, and dilute to 250 ml.

(2)        Distillation.  Perform the preliminary procedure as described in ASTM D1179 paragraph 11.1.1.  Cool the acid-water mixture to below 100° Celsius (C) and add slowly the 250 ml of sample solution.  Mix thoroughly and distill until 250 ml of distillate is collected.

(3)        Prepare a series of standards by diluting 1, 2, 3 and 4 ml of the fluoride working standard to 100 ml in Nessler tubes.  Transfer 100 ml of distillate into a Nessler tube.  Add 5.0 ml of the acid zirconyl-alizarin reagent to each solution and mix thoroughly.  Compare the sample and standard visually after standing 1 hour.

Fluorine, ppm =  A x 1000

S

Where     A = mg of F in standard

S = g of sample in 100 ml of the distillate

4.4  Tests.

4.4.1  Lead.  Analysis shall be made on oven dried solids obtained by the methods of 4.3.4.2 and reported in parts per million (ppm) found in the oven dried solids.  Lead shall be determined by emission spectroscopy or x-ray emission methods.  Equally accurate alternate test methods, approved in writing, may also be used.

4.4.2  Package stability.  A sample container shall be held in undisturbed shelf storage for 60 days. At the expiration of this storage time, the contents shall be manually stirred and blended with a spatula for a period not exceeding five minutes.  The lot shall be acceptable for package stability if within the 5 minutes no undispersed material can be found in the container by using the spatula, and no obviously undispersed material is visible on the spatula blade as it is removed from the container and allowed to drain.

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