Originally Posted by Rob-F
From time to time someone will talk about the importance of using "fine machine oil" on whatever fine machine is under discussion. They always draw out the length of the word "fine," making it last one or two seconds. I've always wondered where you get that, since I've never seen a can marked "fine machine oil" on any store shelves. The only ideas I've come up with are sewing machine oil, as Phil suggests; Hunter fan oil; the South Bend Lathe Company sells oil in cans; and . . . maybe Outer's gun oil? And on turntable bearings, I have used synthetic motor oils like Castrol and Mobil One; sometimes with a little "Slick 50" added. After all, engines are fine machines, albeit more robust and heavy-duty than cameras, watches and turntables.
Usually the same people who tell you to use "fine machine oil" also caution not to use 3-in-1 oil, as if there were something horribly wrong with it. Everyone "knows" that it's only for door hinges, but nobody seems to know what's the matter with it, or why it isn't as good as "fine machine oil." Any ideas?
So: where do you get your fine machine oil?
My own investigations and understanding of oil behaviour is as follows:
broadly there is a relationship between oil viscosity and the ability to resist creep or flow. This is not news of course. Everybody knows that water will flow more easily than honey
It's not that simple, of course. Oils are formulated for different applications according to the requirements of the application. Motor vehicle oils have been trending thinner for years in the interests of improved economy, reduced start up wear by enhancing cold viscosity and reducing resistance to flow. Viscosity improvers and many other additives are added to base oil stocks whether synthetic or mineral-based to meet the needs of, for instance, automobile manufacturers.
OK. Having, (hopefully) provided some context, in relation to camera applications, it will be appreciated that the oils one might need to use in servicing a camera (let's look at a shutter escapement, as an example) will need to have a very low viscosity. Oils that are not super fine are likely to seize an escapement and prevent it running down.
But very, very thin or low viscosity oils, as noted, generally have a tendency to flow readily or "creep". Of course this is usually likely to be a problem inside a camera. You really don't want lubricants to find their way onto the blades of a leaf shutter or onto the optics of a lens. Hence, suitable oils are going to be reasonably specialised, as they must be both low enough in viscosity as to not impede fine mechanisms, but they must still demonstrate resistance to "creep".
This is not a combination of attributes that naturally goes hand in hand; hence I looked for particular lubricants designed to achieve this, and my investigations suggested to me that watch or clock oils were the go. I ended up with Moebius synthetic for long term stability and resistance to oxidation as well as their resistance to creeping when used in the correct quantity
It should be noted these are not all created equal, either. There is a world of difference between the movements in a grandfather clock or even a mantle clock and those of a watch or small clock. Using the wrong oil in the wrong mechanism will cause problems no matter how specialised.
My local specialist clock and watch repairer was helpful enough to supply a vial of superfine Moebius at a very reasonable price, as he has no interest in working on cameras.
That's my take on "fine" oils for cameras as lay person and self-taught repairer still very much on the journey of learning the craft. Hope it helps.