TALKS TO FARMERS.

Waikato Times, Volume 105, Issue 17786, 10 August 1929, Page 22 (Supplement)

TALKS TO FARMERS.

“LUBRICATION OF MACHINERY.” Lubricants was the theme of an address given by Professor Steel at the farmers' winter class at Canterbury C#llcge. He said that lubricants were needed because of the friction between rubbing surface-- of parts of machines. Friction itself was looked upon as a curse, but without friction one could not walk over a floor, nor could motorcar tyres grip the roads. Lubricants were used to make a film so that metals would not touch one another when in action. The ideal oil was the thinnest possible, one that would not in itself create friction but was at the same time thick enough to keep its film intact under pressure. There were three kinds of oils—mineral, animal, and blended. The mineral oil, such as kerosene and petrol, was not so greasy as the others. Linseed oil was a good example of animal and vegetable oil, the characteristic of which was to hang to the surface. Good oils were obtained by blending the first two oils, of which the percentage of animal or vegetable oil was about ten per cent. These blended oils held to surfaces better than did the pure mineral oils. Speaking of motor-cars and cycles,

Professor Steel said that carbon was usually a sign of over-lubrication. This over-lubrication expressed itself also in a bluish smoke which rose when a car was started for the first time each day. Grease, .which was really an oil should be used in gear cases where there was the probability of the leakage of' finer oils. Castor oil was of great value when used at a fairly high temperature, such as in hot boxes on the railways. Castor oil thinned down under heat. It was unwise to mix lubricating oils.