Japan (Paint Additive)
Japan was a drying agent commonly used in the latter end of the 19th century. Its use cut the time expended on painting individual pieces of equipment by a considerable factor:
Painting in the railroad shop is not what it used to be some twenty or thirty years ago, when the painter took two and three weeks or more to paint a locomotive, and if it should be done in two weeks, it would be considered a quick job. In those days, japan colors were not used as much as they are to-day, so that it took longer between coats to allow the paint to dry and most all painters used oil colors with japan or the old-fashioned patent dryers for drying purposes. They were imbued with the idea that a good job could not be done with japan color, it would crack, wouldn't wear long, and there was nothing like oil; but in this age of rush in the railroad shop, oil is 'not in it.' Our superiors expect us to be abreast of the age and to do the work in the shortest possible time, and I think it is our duty to try and meet those expectations."-Thomas Jones, Canadian Pacific Railway, Montreal.
"Mr. Jones' Paper," Railroad Car Journal Vol.VI No.10 October 1896 p247.
Mr. Jones hinted at a common shortcoming of japans, that being that they resulted in a short-lived, brittle finish. Speed of painting turned out to overcome these concerns in the end.
"As is well known to the paint fraternity, ingredients that go to make up a japan are short and brittle, and have been the cause of great annoyance, especially among the cheaper grades. They are not at all calculated to promote harmony among the different coats applied in painting of either wood or iron, for while oil retards, drying japan promotes it and the antagonism between the liquids would naturally bring about anything but favorable results."
"Protective Paint for Metal Parts of Cars and Trucks," Railroad Car Journal Vol.VI No.11 November 1896 p279.