Originally Posted by
crocee
Why and how would grease go bad? I can understand if it was used previously or contained contaminates or in an open container. Standard grease from what I can find out is a specialized mix or oil and soap, synthetics is another story. If the container had been kept closed what would make it go bad?
oxidation and temperature and containers may play a part. also if it's not sealed well enough, who know's what happened with the container between the 50 + years that it's been kept. increasing the temp by 10degress will double the rate of oxidation. also if there's a slight gap in the cover or if cover is not tight enough, that's another factor for oxidation. singer grease/lubricant can be had for less than $4/container. others might do it differently but for me i wouldn't use a grease that's been sitting in a container for 50+ years - again, that's just me. if others have been using stored grease on their machines and it's working OK then that's well and good. thanks.