CASTOR-OIL INDUSTRY. 



33 



Table X. — Analyses of castor oils from, various sources, showing the effect of heating upon 



acidity. 





Description of sample. 



Acidity (per cent). 





Control. 



Heated. 





0.47 

 1.00 

 .71 

 .92 



0.58 



C P. No. loil 



1.05 





.79 





.96 







It is thus evident that heat alone has little effect on the acidity. 

 This question arose from the possibility that if such acidity did 

 develop, it might operate to pit the walls of the gas-engine combustion 

 chamber during a run. 



When the Bureau of Aircraft Production went into the market for 

 castor oil for lubricating purposes it drew up the specifications 

 listed below, giving the properties which a good grade of lubricating 

 castor oil should possess. Since these properties are possessed only 

 by a high-grade No. 1 oil, these specifications may be accepted as 

 fairly representative of this entire grade, regardless of its intended 

 use. 



General. — (1) This specification covers the requirements of the Bureau of Aircraft 

 Production in. all purchases of castor oil for rotary-engine lubrication. The oil must 

 be a high-grade vegetable castor oil suitable for this purpose. Both cold-pressed 

 vegetable castor oil and hot-pressed vegetable castor oil which has been refined sj 

 that it will meet the requirements of this specification may be submitted for purchases. 

 (2) The castor oil must be free from adulteration, other oils, suspended matter, grit, 

 and water. (3) The castor oil must meet the following requirements: 



Color.— (4) When observed in a 4-ounce sample bottle, the castor oil must be color- 

 less or nearly so, transparent, and without fluorescence. 



Specific gravity. — (5) The castor oil must have a specific gravity of 0.959 to 0.968 at 

 60° F. (Baume gravity must be from 16.05 to 14.70 at 60° F.) 



Viscosity. — (6) The castor oil when tested in a Saybolt universal viscosimeter must 

 have a viscosity of not less than 450 seconds at 130° F. and 95 seconds at 212° F. 



Flash point. — (7) The flash point must not be less than 450° F. in a Cleveland 

 open-cup flash tester. 



Pour test. — (8) The castor oil, in a 4-ounce sample bottle one-quarter full, must 

 not congeal on being subjected to a temperature of plus 5° F. for one hour. (See 

 specification No. 3525, "Pour test.") 



Evaporation test. — (9) The castor oil must not show a greater loss than five-tenths 

 of 1 per cent when heated in an oven at 230° F. for If hours. This test shall be made 

 on a 5-gram sample in a glass crystallizing dish approximately 2\ inches in diameter 

 and \\ inches high, inside dimensions. 



Ash. — (10) The castor, oil shall not show more than 0.015 per cent of ash and shall 

 ohow no impurity of any sort not related to the original product. 



Solubility. — (11) The castor oil must be completely soluble in 4 volumes of 90 

 per cent alcohol (specific gravity 0.834 at 60° F.). This test shall be made on a 2 c. c. 

 sample. 



