Light Weight oil for Coolant

[Dave_C]

With all the coolant issues I've heard over the years, IE: It stinks, it rust the machine, wrong dilution ratio, etc.

I'm told that oil is not a great conductor of heat! Well not as good as water...

But if I don't need a lot of heat rejection and just need some flood to remove swarf and lube the cut, would not some light weight oil work? I've used WD40 on aluminum from day one. Only objection is the smell. Will oil smoke as well, probably will I suppose.

I've read that oil will break down under heavy cuts.

Anyone have any thoughts or experiences they could share?

Dave C.

[Harold_V]

There should be oils on the market that are intended to be used as coolant. One of them is lard oil, assuming it's still available. It used to be used routinely, depending on the material being machined.

I'd highly recommend you do a search. I've been away from the shop too long to be able to speak for what's available today, but, yes, oil is acceptable, and in some cases, preferred. I know for fact that Litton Guidance used nothing but oil for coolant in their #1 B&S grinder, as some coolants yield contaminants that are not acceptable for assemblies, even after being well cleaned. Chlorine, for example.

The one real negative of using oil as coolant is the resulting mess. Oil-Dri (or equivalent) is pretty much mandatory.

Harold

[Rick]

Like Harold said "messy ". Oil will also form a mist depending on the machine/process and its gets on and in everything and sticks. I deal with one manufacturer that uses oil exclusively and they even have oil zorb inside some of the electrical cabinets. That that will a grain of salt, this company runs an bunch of multi-spindle lathes that sling oil everywhere. I wouldnt expect much misting in the home shop environment

[Dave_C]

Thanks,

I'm not sure oil is what I want to do but mainly was trying to stay away from rust issues with water mixed coolants due to some low use periods in the home shop.

I took Harold's suggestion and did some research. There seem to be better coolants available that don't rust.

No hurry, I'll do some more reading.

Dave C

[DICKEYBIRD]

Hi Dave,

I've been using Re-Li-On cutting oil for years and like it. It doesn't take much to do the job and is reasonably priced. I get it from Enco. It does smoke and stink though, depending on how fast you're cutting. I think you'll have that no matter what oil you choose.

Will you be using a flood system? I don't have a flood setup on my lathe or mill and it would require a major re-vamp to do so. On my little ORAC lathe I built an adjustable drip feed system using a 12vdc motor & a cheap ebay Suzuki dirt bike oil injection pump switched on & off by Mach. It works pretty well and prevents most of the oil slinging all over the place.

[Dave_C]

Milton in Tenn,

Yes, I will have a flood coolant system. I have all the wiring done now and just need to purchase the tank and pump.

Oil seems to have draw backs as well so I'm looking for a good trade off on some form of flood coolant.

SYNKOOL SS is looking pretty good right now unless someone tells me it has issues with rust!

Dave C.

[Bob D.]

At the manufacturing plant I work at they were fluting rifle barrels lengthwise with ball end endmills with a VMC CNC. They used rapeseed oil for coolant. Worked really well.
From my maintenance point of view, it was messy and everywhere. Didn't gum up stuff, no rust, didn't take the paint off, left your hands baby soft! Didn't smell bad.
Didn't require coolant system mods, was expensive. Didn't smoke but it was a flood application.
Only used for that process, water based everywhere else.

Bob D.

[Dave_C]

Here is what I found:

Mobilmet 426 oil is primarily a dual- or tri-purpose cutting oil for automatic screw machine shops. It may be used as a cutting oil and/or a lubricating oil. It offers high lubricity and maximum cooling on hard, clean-cutting metals. This makes it especially suitable for high surface speed machining of screw stocks, aluminum, and brass. It also can be used for the general machining of nickel-tin-bronze alloys and the free-machining of steels, as well as for severe cutting operations of difficult-to-machine non-ferrous alloys, including silicon-copper, silicon-bronze, and copper-nickel. Such multipurpose applications minimise contamination caused by leakage from the lubricating system into cutting fluid reservoirs. Its outstanding lubricating qualities provide cool-running spindles and long clutch life. Mobilmet 404 provides superior machining and lubricating performance plus the added benefit of the virtual elimination of oil mist in high-speed machine tools. This relatively light-coloured, transparent, low-odor oil has excellent oxidation stability at higher temperatures and outstanding lubricating properties under heavy loads and high speeds. It has excellent resistance to foaming, even with excessive splashing, so that superior performance is provided in the machine tool lubrication system. It will provide adequate film strength in hot-running machine tool bearings under load. (Replaces Mobilmet Omicron - Formerly Mobilmet 404)

Dave C.

[redneckalbertan]

They used rapeseed oil for coolant.

You don't hear the term 'rapeseed' very often anymore.

[wsippola]

They used rapeseed oil for coolant.

You don't hear the term 'rapeseed' very often anymore.

No you don't - just Canola. Had to look up the difference - Canola was bred from rapeseed which got rid of a couple less desirable chemicals in the oil.

Something interesting from Wiki "Its use was limited until the development of steam power, when machinists found rapeseed oil clung to water- and steam-washed metal surfaces better than other lubricants."

Sounds like Canola oil might be a good steam lubricant as well.

[Bob D.]

The rapeseed oil was used about 12 years ago. The rifle barrels were stainless steel with 6 flutes machined down the length of the barrel. Tremendously improved tool life compared to several water based coolants that were tried. Sure must take a lot of seeds to squeeze out a 55 gal barrel full!! I think they are similar in size to grass seed.

Bob D.

[redneckalbertan]

The rapeseed oil was used about 12 years ago. The rifle barrels were stainless steel with 6 flutes machined down the length of the barrel. Tremendously improved tool life compared to several water based coolants that were tried. Sure must take a lot of seeds to squeeze out a 55 gal barrel full!! I think they are similar in size to grass seed.

Bob D.

They are about the same diameter as grass seed but spherical as opposed cylindrical like grass seed. A little larger than a mustard seed, from what I understand I've never seen a mustard seed.