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Thread: cutting oil
02-15-2012, 09:20 PM #1
Finally decided to hook up my 9" by 48" south bend lathe. ( family heirloom) Trying to find a good grade cutting oil and something to pump it. Several posts suggest mobilmet 404, but it seems that it has been replaced by mobilmet 766. This seems to be a thicker cutting oil. Since lathe usage will be intermittent, i think oil will be best (rather than water soulable_) Really need a light grade cutting oil and someway to pump it. Need to be able to restrict flow (valve) so maybe sometimes a lot, maybe sometimes a little. Most pumps I see don't like heavy fluids and don't like restrictions. Mobilmet 766 $69.00 at enco with free shipping.
Anbody got any clues.
Believe it or not I even got an original South Bend Drill Press. I know a thing or two as I was a machinist for several years. Problem was, electricity paid more so I changed occupations.
any suggestions would be welcome
02-16-2012, 12:07 AM #2
02-16-2012, 08:41 AM #3
I pretty much only use flood coolant when working with stainless steel - your lathe probably doesn't have the splashbacks etc. that the shop machines had and flood coolant gets very messy, you will have a wide line of oil right around your shop within a few days!
Like others I tend to use a cutting fluid in a dropper bottle for most of my work, although my local supplier now only sells it in tins as a more grease like compound. I don't know if it is available outside the UK, the type I use is called CT90 and calls itself cutting and tapping fluid.
My pump system is full of water soluble cutting oil, like I say irregular use, and this is it's third winter outside and I haven't been aware of any damage to the tank from it freezing - it must have frozen in that time, everything else has! What I don't like about the water based oil is that eventually the chips that get in it, rust - yuck!
02-16-2012, 08:58 AM #4
Machinists are working stiffs who brown bag it for lunch. It's thus traditional to use a washed tuna can for cutting oil, and an acid brush. I've never needed anything more on the lathe or drill press.
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02-16-2012, 09:14 AM #5
there`s always this option- a 1 lb package will net you about 250ml once cut 50/50 with kerosene.
cost only about 3-4 dollars, and you get to eat the bacon.
02-16-2012, 02:34 PM #6
Perhaps I am a nervous person, but I don't like random oils (water based or otherwise) getting all over me. I am not running any kind of production when a continuous oiling set-up would be helpful. I breath enough weird fumes and have enough chemicals get on me, I just don't want any extra.
I like a good trigger type oil can filled with the cheapest gallon jug of thread cutting oil the plumbing supply store has in stock. A gallon lasts me a long time and I don't use it very much. The stuff is pretty thin, like 5 or 10W motor oil.
When I am doing a job that I really care about I dig out my ancient can of SOS brand Dark cutting oil that stinks of sulfur. I don't know if it is any better but it gives me a warm feeling inside that I am doing something special for that hard reaming or tapping job at hand. I am pretty sure at the rate I use the dark cutting oil my grand kids will be inheriting it from me, which would be fitting since I got the can from my grandfather.
But I guess to answer your question I would use the cheapest oil you can find since invariably you will get some grit(sanding, grinding, rust, etc.) or other crap into the oil and want to pitch it all out.
02-16-2012, 04:21 PM #7
I've been doing what machinists have been doing forever- using a pump oil can or brush in a can of cutting oil. For cutting oils:
-Dark Sulfur cutting oil, available at Home Depot and Lowe's (usually in the plumbing department as it used for threading pipe) works quite well for drilling and turning of most carbon steels. It is inexpensive. The downside is it makes a mess of the machine and does smell somewhat.
-Light Cutting Oil, also offered to plumbers, is a pretty good alternative.
-for turning or machining aluminum: spray on WD-40. Aluminum must have a thin lubricating cutting fluid. Oldtimers used straight kerosene. for a small lathe, WD-40 in a pump container (buy a gallon and get a hand squirt container) will be plenty good.
-Lard Oil: This is the oldest and one of the best cutting lubricants. It has been used by machinists since the beginnings of the art. Oldtimers simply took the bacon drippings from the skillet or griddle, and used them as cutting lubricant. I mix my bacon drippings about 50:50 with diesel fuel and then add a little "tractor hydraulic fluid" (which is DTE Heavy Medium, a good all purpose oil for plain bearings or other mechanism parts). I pour off the bacon drippings while they are HOT and fluid, getting them into a good sized can. Once I have the drippings in the can, I head out to the garage and pour in the diesel fuel and tractor hydraulic fluid. Mixing while the drippings are fluid and hot assures a uniform cutting oil with no globs of lard floating around. This works wonders when turning steels, stainless steels, as well as for milling, drilling, reaming and tapping. I put it on with an old pump oil can. It is far less messy and nowhere near as aromatic as Dark Sulphur Cutting Oil.
IMO, a 9" Southbend lathe is not a machine that will need a coolant system. Unless a person were running heavy long cuts or running production work, I would not think a recirculating coolant system is required.
We do use the portable misting systems on the machine tools in the powerplant shop. This system uses compressed air to aspirate and atomize a fairly concentrated coolant. The coolant is formulated for this type of misting device. When we machine austenitic stainless steels or drill stainless steels, we have found the misting system makes a world of difference. However, the misting system is total loss and creates an airborne mist that gets all over the machine tools and into the ambient air. for a home shop in a small space, this misting system would not be a real good idea.
I keep an old kippered herring tin on the lathe with a brush for putting on the cutting oil, and I keep the pump can full of lard oil/diesel fuel mix in close reach. I also keep a spray can of any cheap penetrating oil for machining aluminum. The word is WD 40 works the best, but I use what is at hand and make out OK.
Another thought: if the 9" lathe does not have a chip pan, you might want to make one and get it between the lathe and the bench or stand. A chip pan makes a world of difference in how clean the rest of the shop stays. Cutting oil soaking into a wood bench top, or simp
BTW: re: dark sulfur cutting oil. The stuff has been around forever and it does work. As a little kid, I remember my father always had a can of "Hercules" Dark Sulfur cutting oil in our home shop. We lived in one apartment of a 4 family house my Dad owned. The piping was vintage 1920's, screwed red brass and screwed galvanized for the water, screwed black iron for the gas and steam heat. Sooner or later, either the hot water ate out a valve, or something needed dismantling such as re-pitching the radiators to get rid of condensate knock. We usually wound up cutting and threading and "letting in a union", so the dark sulfur oil got plenty of use. Dad kept the dark sulfur oil in a "Goldenrod" pump oil can. As a little guy, I'd squirt the oil while Dad heaved on the diestock. Dad swore if he did not get the dark sulphur oil on the threading, the die chasers would tear the threads.
One day, when I was about 8, I was wearing a pair of Sears Roebuck coveralls my mom cut down and took in to fit me. I was helping my Dad with some repair or other on a Saturday. Dad asked me to go to the corner mailbox and drop some letters. As I started down the street, the older kids started ragging me about the coveralls and my walk (which has a kind of bounce to it). The block bully, a kid of 16, a real nasty lug who was well over 6 ft tall, got behind me and started spitting phlegm onto my head. Of course, the crowd of other toadies egged him on. I knew if I tried anything, I was going get rat packed and smeared onto the sidewalk. I held my peace and vowed revenge.
Come the next weekend, pretty much the same scenario. Dad asked me to go to the corner mailbox. I detoured to the pipe vise and put the Goldenrod oiler full of Hercules Dark Sulphur Cutting oil in my pocket along with a rag. I proceeded down the street, taking my time. The loafers on the stoop of this one house were in full cry about my walk, my coveralls, and all else, asking if I wanted anymore spit on my head. Out came the block bully, and he got behind me. I heard him rasping and working up to fire a round onto my head. It was every bit as juicy a victory as david and Goliath. I turned around and nailed him full in the eyes with Hercules Dark Sulfur Cutting Oil before he ever had a chance to let fly with his lunger. I kept pumping, covering his head and clothing until the can was empty. The bully could not move, screaming and howling. The crowd switched sides in part, some hollering how I had "killed" the block bully (amazing how fast people can switch sides) , and some loyal toadies telling me I was dead. I was past caring, hoping there were some cuttings from the pipe reamer or diestock in the cutting oil, and imagining what an 18" Rigid wrench would do next time around.
Now for the funny part: The block bully was the son of an equally obnoxious and short tempered man who happened to be a licensed plumber. The licensed plumber had beat up at least one neighbor, and he had it in for my old man, who was a construction inspector. I told the old man what went down. He drew on his pipe and laughed, touseled my hair and said: "Let the s--b's come on, they can all go to hell." I never had another problem and never heard another crack about my coveralls or my walk from the whole sorry bunch.
The plumber must've known what his son had been up to, or maybe he was afraid to tangle with my old man, as we never heard another word out of them.
Dark sulphur cutting oil- GREAT STUFF !!! who needs "conflict resolution" or whatever the new "politically correct" solution to disputes is ? Dark Sulphur Cutting Oil, works like a champ and leaves 'em rolling on the sidewalk, not knowing what hit 'em.
02-17-2012, 08:01 AM #8
You could fabricate a can mounted behind the tool post with a valve to drip any type of coolant you desire.
02-17-2012, 08:40 AM #9
Curious George sir,
Mobilmet 404 has been replaced by mobilmet 426. Mobilmet 766 contains sulfur. 404 is a straight non reactive mineral oil..
For what it's worth.. I've used an acid brush and just 'painted' oil on parts for years.. Much simpler and less mess than a pump and oil sump system..
Also I find nu-clear cutting oil by ridgid ( thread cutting oil available at most plumbing supply houses) to be a pleasant cutting oil to work with.
I use the heavy sulfur oils for thread cutting only.. I live in a high humidity area and I don't want any water and sulfur any where near cast iron or steel.. Water isn't so bad but combine it with sulfur and you get a substance I'd rather not have around..
I stay away from both the water soluble stuff and the synthetics as my body reacts badly to them.. And as a positive.. working with the straight mineral oils leaves one's hand nice and soft.. and without trying to sound to 'girly' it's nice to have soft hands after many years of doing construction..
Hope this helps..
PS if you look up the msds ( material safety data sheets) on mobilmet 426 you may find that the bucket it comes in is more hazardous than the oil it self..
02-17-2012, 07:14 PM #10
Plus 1 on what Conrad said. Acid brushes are cheap, tuna cans cheaper. I steer clear of the water soluble stuff after having a machine rust many years ago. Besides, in my experience the water soluble stuff is not the best for cutting threads. I use dark high sulphur oil for threading and Chevron metalworking fluid for the rest.