In the world of lubrication, hot topics come and go. Whether it’s synthetic oil, electric motor lubrication or ultrasonic-assisted regreasing, certain themes take on a greater profile from time to time. Lately, the hot topic that I’ve seen and have been asked more questions about than any other is varnish. From compressors to gas turbines, hydraulics to gearboxes, everyone seems to be talking about varnish. But, what is varnish? What causes it? And most importantly, how can it be prevented or eliminated?
