I have covered samples of 12 different oils under observation, upon my bay window since 12/28 of last year. Some remain completely fluid, some have gotten much thicker due to their solvent loss, and some have clouded over and jelled to the point of no movement. So which ones would you use on your sewing machines ? Both Kroil and Tri Flow have a goodly percentage of light solvents that will evaporate, leaving a somewhat heavy oil that still flows after over 5 months of exposure. Tri Flow is a bicycle product, with 40 % solvents, designed to dissolve and flush away old lube deposits and leave an oil deposit. Old sewing machines can benefit from that logic. In my mind, a fresh clean sewing machine doesn't need the solvent, just the lube oil. My oil of choice is Mobil DTE Light turbine oil. My metal cutting machines spec this oil in their transmissions, so I have 5 gallons. If I desire the solvent flushing action, add 40% light solvent such as kerosene or charcoal lighter fluid. For the same smell as Tri Flow add 4 % amyl acetate (banana oil). To learn the content of commercial products, read their online MSDS (Material Safety Data Sheet).
John in WI