Call me crazy (using hydraulic oil as a flood coolant)

I won't call you 'crazy', but I think you're taking a bit of a risk. Hydraulic fluid is a lubricant, not a cutting oil.

Good idea here, I'm going to copy it.

IMHO, oil is great in production machines, especially screw machines. But I think you're crazy using it for HSM, one of, two of, kind of work. You'll soon have a light coat of oil over your entire shop which will attract dust and become grime. Unless you spend forever cleaning the oil off of everything.

I'd really like to know what you think after using it for a year.

Karl

Oh yeah... another point is that that oil won't be as heat-stable as water soluble coolant. On a small machine using HSS tooling, no biggie, but when you're running a machine that needs to work for a living... I think you might find yourself disappointed. Still, it's a relatively cheap experiment.

Just a word to the wise: The air vent hole is a little to small to get the garden hose into. I found that if I just forced my funnel down into it that the hole easily expanded enough to accept the hose and after a bit the plastic tries to resume it's original shape (size) and you wind up having a devil of a time getting the hose back out.

It may seem funny but I do very little one or two of's as I am always striving for production work and I already have rancid soluble all over every tool and thing in my shop. Such that I have to wash after touching "ANYTHING' in the shop. Otherwise I wind up applying "the ointment" (Lamisil C Cortate 1% AA)

Hydraulic oil could not possibly be worse.. We'll see!

There are pure oil "metalworking fluids" like Mobil Omicron and Mobil Omega that have proper cutting-oil properties. According to the sheet Omicron also claims application as a hydraulic oil.

I use Omicron for flood coolant on my lathe because I am not willing to subject the lathe to anything else. It'll get used for a week and then may sit under its bedsheet for months. Likewise my old K&T mill because it is "leaky" and the soluble gets into the gear cases and make a mess. The Omicron is more useful for clearing chips in an awkward cut than as a coolant per se because it smokes at a low temperature. In my experience the chip clearing is more useful anyway as it is the key to getting a predictable finish.

I am strictly an amateur here so apply your own advice filter...

Bob

In the dark recesses of my mind I recall that one of the group's more experience contributors, Fitch Williams, recommended a 50/50 mix of hydraulic oil and paint thinner as a milling flood liquid. I never tried it myself but Fitch never gave us a bum steer so I wouldn't hesitate to try it if I need it.

I looked it up with google and here's what Fitch had to say:

"On the Mill the fluid needs to be more viscous and to move with higher velocity to move the chips out of the way. Straight oil is too thick for my coolant pump so I use a mixture of the cheapest hydraulic oil I could find ($19.95 for 5 gallons) and mineral spirits (paint thinner). The mixture starts out a bit more than 50% oil and over the course of a year, some of the thinner evaporates out and it gets thicker. When it gets to thick to blow the chips out of the way, I add more thinner. Not to scientific, but it works just fine and the mill never grows black algae, the stuff never develops growths in the tank, doesn't start to smell like something died in the tank, and nothing rusts."

HTH Rick Renner

I can't imagine why you have such trouble. I've been using the same bucket of mixed soluble oil in my shed for *years*, and I have no problems. Doesn't smell bad, doesn't cause any skin problems... nothing. I damned near *bathe* in the stuff at work, though it's not nearly as old at work.

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foundry and general metal working and lots of related projects. Regards Roy aka Chipmaker // Foxeye Opinions are strictly those of my wife....I have had no input whatsoever. Remove capital A from chipmAkr for correct email address

I've found that some oils go rancid much faster than others. The stuff I use now, blasocut, has never gone rancid. It has no bacteriocides either. In fact, it is non-toxic. Tastes like shit though... And it doesn't change the way your coffee looks if you already have cream in it. ERS

I'm not asking about this. Nope. Nuh uh. No way....

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

Jim .... you've got a good sense of ha ha ,,, not sure how good your stomach is, but the ha ha is working fine!

Bill

My experience with soluble oil is that it's great as long as it never gets infected. They had never had any problems at my previous employer for years (like in 50+). Then while I was working there I opened the back of the Cinci mill one summer day and saw fuzz growing all over the works in there. From then on we had nothing but trouble with the soluble oil going bad in less than 6 months. It didn't stink so much as simply went bad. It would turn brown and if left long enough all the oil would just fall out of the water and turn to sludge in the bottom of the tank. We never did manage to stop it while I was there (and I went to extremes trying to clean everything before putting a new batch in there). We even went so far as to try a semi synthetic oil which was what was in the mills when I bought them. I sold the old Cinci not long after that but I've still got the Abene. After flushing the system and putting in a good quality anti rust soluble oil I've not had any problems since. My only guess is that the synthetic (which had lots of things in it including pine oil) finally killed all the bacteria. Wayne Cook Shamrock, TX

Do you think trouble with the soluable oil water mixture is a North/South thing?

I've never had a problem - Minnesota ( my surface grinder sump has got to be two years old)

Mike Graham has not seen it - Canada

Or have we just been lucky? I've seen many from the south 1/2 of the USA say nothing but trouble. Anyone in the north having problems?

Just a wild ass guess

Karl

Bill Darby is in Ottawa - even farther north than I am.

But it does work ok as a cutting oil. Not optimum, but ok.

Gunner

"What do you call someone in possesion of all the facts? Paranoid.-William Burroughs

I would say it has to be related to temp extremes. I can pressure wash and then wash again and rinse my concrete walks and patio slab with clorox, and within 48 hours mold and mildew is already starting to grow back. Its the heat and humidity IMHO that is detrimental to the water soluable oils.

Just a thought, its pretty common for folks around the south to use zinc or copper strips on their roofs ridge cap, so exposure to weather leaches out the compounds that kill off algae etc. I wonder if putting some strips or pieces of copper or zinc in the resivoir with water soluable oils would help eliminate this critter growth.

I admit it does get hot and it also gets humid up noth, but its not like in the deep south by any means. I wonder how it lasts in the SW sections of the US.......

When I lived up north, I was able to store diesel fuel and heating oil for very long periods of time. Here it does not take long for the diesel fuel to start to grow critters in it, and it sure does not store very good for any length of time.

Has to be temp / humidty affected.

-- Visit my website:

foundry and general metal working and lots of related projects. Regards Roy aka Chipmaker // Foxeye Opinions are strictly those of my wife....I have had no input whatsoever. Remove capital A from chipmAkr for correct email address

Yer crazy !!!

Sorry. I was waiting for someone with something useful to say (not me) to preface their remarks with that, but couldn't wait any longer.

Apparently no else here shares my low sense of humor. : (

R, Tom Q.

p.s. Good thread.

Thanks Tom!!!!! That's what I asked for... and you gave it to me!! Seriously,, if the hydraulic oil dosen't work out I'll replace it with Omicron or the nearest thing to it that I can find here in Canada. (Would anyone know what the equivalent stuff would be from Sunluight oil, Shell, Petro Can, or Esso)

Thanks for all the great replies guys!

Bill

Bill, I've been using Fitch's receipe (see Rick Renner's post) for a couple of years on the milling machine. I've had no problems with it, and everything in the shop isn't covered with a film of oil. (The floor around the mill is another story, but that's what kitty litter is for.)

Since the other half of the shop is set up for woodworking, I try to minimize the sources of moisture in the shop. To me, using soluable oils is just asking for rust on the woodwqorking tools.

Regards, Ed Bailen