Re: Galvanized roofs


Dennis Storzek
 

I have always wondered if it wasn't an issue with the paints in use during different periods. During the era before WWI and 'tween the wars, the common freightcar paint was some sort of cheap pigment (almost always iron oxide based) in linseed oil, a naturally polymerizing oil. Linseed oil leaves a lot to be desired as paint, it's a potential fire hazard, takes forever to dry, and stays soft for a while even when dry to the touch. But it does form a tough flexible film that sticks tenaciously.

Beginning just before WWII synthetic alkyd enamels became popular. These solved many of the application problems inherent with linseed oil, and the other popular freightcar coating, asphalt based car cement, but perhaps at the cost of lesser adhesion, and that is when peeling roofs became more common. Remember, the railroads weren't looking for the BEST freightcar coating, only the most cost effective. That still holds true today, or freightcars would be painted with Imron. Given the reduced application costs, and the fact that "nobody sees the roofs, anyway", the railroads just made a judgement as to what was sufficient for their needs, eventually deciding that it was a waste of time to paint roofs at all, but somewhat after our period of interest.

Dennis Storzek

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