Machining, grinding, and turning coolants

[Mic]

Hello,
I am wondering what types/brands of coolants others use in their machine shops for all around machining? I would also like some information on what types of oils you are using for hydraulic grinders? What types of way lube oils are you using for your grinders and machining centers?
We use DoAll Kleen Kool 777 for all grinding, machining and cutting coolant. We use Mobile Vactra oil No.2 for all of our way lube. In our Okamoto grinder we use Shell Tunna V oil 32. In our Kent grinders we use Mobile DTE 25. For tapping and drilling on our manual mills we use Monroe Cool Tool 2.
Any information would be greatly appreciated.

 

[tom slick]

this is a little bit of a late reply but here it is.
in the 2 machine shops i have worked in they have used only hangstefer's coolants mixed with tap water and mobil vactra and DTE or chevron gst oils depending on the machine's manual. i forget the ISO numbers but is is whaterver the manual calls for. the production shop ran only fadal VMCs (no other machines) and worked mostly aluminum. the other shop machines a variety of materials but mostly aluminum on a VMC. neither shop has problems with lubrication or coolant issues.
one interesting side note. at my current job we use specially modified fadal VMCs to machine wood, so they don't use coolant spray. you'd be amazed at the amount of problems that are caused without coolant spraying everywhere- washing and lubing all the other parts of the machine such as doors and rollers. the dust gets into everything too and gums them up. i've had to clean packed sawdust (mixed with way oil) out of the ways, not fun.

 

[cc rider]

It's been about ten years since I worked around metalcutting, but when I did it was at a Toshiba plant making large electric motors, cutting cast iron, and at Texas Instruments cutting lots of aluminum. At TI we used 'TRIM' products, mostly TRIMSOL water-based coolant. They had a high-pressure version called TRIMSOL-S that had sulphur added for particularly nasty metals like Kovar (a high-nickel steel alloy used for radar components. Same coefficient of thermal expansion as Pyrex glass.) All the water-based coolants are basically an emulsion of oil and water, with some magical stuff thrown in to prevent rust, reduce smell, etc. Water is still the best heat transfer liquid around (and the cheapest), and the oil is just added so there's no corrosion.

The biggest problem with water based coolants is tramp oil contamination and the resulting stink. The stink is caused by a bacteria, pseudomonia oliovorans or something like that. Basically it eats the oil (they use a similar bacteria to fight oil spills) and produces a VERY unpleasant odor (among other things) as waste product. 'Infected' coolant also can cause contact dermatitis, which looks like poison ivy on your hands. There's a bunch of brands of water-based coolants, we used TRIM and CASTROL and some others I can't remember. Once you go down the water-based road, maintenance is very important; you can't just leave it like oil-based lubes since it will go bad. TRIM used to make a line of coolant maintenance products, including my personal favorite, The Yellow-Bellied Sump Sucker. It's a big tank used to suck old coolant out of machine sumps, for transport to the cleaning station. Water-based coolant is cleaned using two basic methods: skimming/filtration or centrifuge. TRIM was very proud of their centrifugal technology to remove contaminants from coolant. But lower-tech solutions like belt skimmers and filter work okay too.

This is probably WAY more than you ever wanted to know. But I spent a lot of time working around that stuff and hardly ever get to share that specialized expertise; sorry if I bored you to tears with my rambling.

Good Luck, and Happy Machining!

c.

Tom: yeah, wood dust is BAD. It tends to suck way oil out from where it belongs, too, so maintenance is crucial. I wonder if a fluorinated grease/oil would be worth it in those applications. Fluorinated lubricants (Krytox is probably the best known) is obscenely expensive but is VERY resistant to contaminants.