Cooling for Milling / Turning - When is oil appropriate?

[ewest]

I work in a small tool shop - part of a larger company. Mostly we make parts for machines to replace the ones that are gruesomely destroyed by our untrained team of barbarian floor mechanics.

There are six guys plus myself, and the running joke is that "Top export Albania is smoke and noise!" and it's because a couple guys (yes they happen to be directly from the old country) douse everything they cut with heavy oil, and it fills the entire room with obnoxious, disgusting oil smoke. We cut mostly aluminum and 304 stainless. What really drives me nuts (and I don't know if this is justified or not) is that when they get on the CNC mill, they douse everything THERE with oil as well, and then it gets in to the sump and makes sludge.

Mind you, every machine here has it's cooling system filled with water and $40 a gallon coolant, and we're not cutting gears here either!

Am I correct to assume that for most operations except honing and tapping, etc, that the use of oil is completely pointless when you've got high end coolant available? It's driving me nuts! I'm tired of the smoke! It coats everything in a thin layer of oil, including our wire EDM, my lungs, the computer screens, etc, and it's irritating... and when they run out of whatever motor oil or gear oil or hydraulic oil they're using, they go for way oil. I know about a little WD40 when you're cutting aluminum, but this strikes me as silly and antiquated.

I'm about to explode over this. Am I correct in my thinking, or should I just get a more powerful ventilation system installed? Might not be a bad idea anyway, because a lot of PVC runs on the lathe, and the hot stringy chips that are made emit some pretty nasty odors, which can't be good for you.

Weigh in? Why use oil when you've got proper water based cooling available?

[Geof]

Can't comment on honing but when you have a proper coolant available that is what should be used. Oil, mineral oil, lubricating oil, motor oil...whatever you call it, and no matter what the additives for a specific application, is not a good coolant or cutting fluid for anything in my experience. Apart from the fact that it creates a horrible oil mist which as you say coats everything.

[Skeeterd5150]

When oil is smoking is it burning? Right? And if it is burning it is really not cooling anything. Maybe lubricating but not cooling. Water is (in my opinion) the essential ingrediant in cooling because of its thermal conductivity properties. Your cutters must be running really hot. Do the "albanians" burn up alot of cutters?

[eorourke]

Skeeterd is right. Oil is not a good coolant but an excellent lubricant. I would only use oil if I were tapping or honing and just for it's lubricating properties. Tell your co-workers that not only are they screwing up the sumps but also the atmosphere. You might have to manually show them that there is no advantage for using oil in other operations.

[ewest]

Skeeterd asked.. "Your cutters must be running really hot. Do the "albanians" burn up alot of cutters?"

Heh, yep. They have whole toolboxes full of trashed mills. The population has stabilized though, since they re-grind most of them until they're stumps (and only work with the sides of them)

The thing is, it's a big air conditioned building, and we only have one window. When the fog rolls in to the machine shop, and it's 100 degrees, humid, and smog choked, it's hard to say what's worse. Of course the the AC doesn't work well in here either.

Time to cut down the oil.

Thanks fellas!