Originally Posted by johnm

Hi Joe,
The oil samples are in clear "watch glasses", with a loosely fitting, clear, perforated, covering. The samples are upon a south facing bay window so that they are exposed to sunlight, open air, UV rays, and normal daily temperature changes. Solvent evaporation and oxidation can occur normally. When I stated that regular sewing oil is good enough for old, sm, I didn't mean to imply that I was looking for 100 year old oil to apply to my sm. A modern, plain sewing machine oil is far better than any oil that was available in the past. This is the reason for the research, I will know that the oils that I use are non gumming, at least during the span of my observation.
John