What's new
What's new

Coolant on old machines designed for cutting oil

slipalong

Plastic
Joined
Mar 26, 2019
Hi Guy's,

after some advice. Have got my 1980's era Cincinnati 2MK up and running and have smoked a couple of end mills so need to get some coolant sorted. The machine is designed for cutting oil I believe, but what's the opinion on using some sort of coolant. On my other machine I use a water soluble oil but Im worried about the water getting into the ways. The mill have a lubrication system be I think half the flow regulator things are blocked so Im manually oiling at the moment.

Thanks,

Ian.
 
What you are doing, not the machine dictates what coolant you should use.
If you are using the old machines the way they were originally designed running low speed and large depth of cuts, oil is far superior but if you are trying to run 1000 sfm and small DOC and high feed rates the water based coolants seem to be better.
This has to do a lot with thermal, metals etc.
Think heat treatment some steels are quenched in water, some in oil, some in heated oil etc.
The other consideration is how are you using the machine, if it's just once in a while the oil doesn't evaporate, stink( grow stuff) , rust your machine etc .
On the other hand water is cheaper by far.
I own a repair machine shop and my newest machine is a 80s lathe and oldest is a 1905 Bullard. Some of my machines only get run once a month, we do a lot of weld build up and machine, some of the machines are large like a boring mill, and I do a lot of big DOC with slow feeds. Oil works a lot better for me.
Good luck
Mike
 
I absolutely hate oil as coolant, the shit gets everywhere including on you. But the machine and cutters will love it, kind of like hogs in a wallow on a hot day. I would go with oil in your case.
 
I absolutely hate oil as coolant, the shit gets everywhere including on you. But the machine and cutters will love it, kind of like hogs in a wallow on a hot day. I would go with oil in your case.

I never thought of it that way probably true. Thanks for a good morning laugh
 
I use water soliable coolant in our 15x48 Colchester Clausing lathe (1960's vintage), and in our big Fosdick sensitive drill press (1930's or 1940's). Both don't seem to mind so long as i keep it diluted right and keep up with all of the other maintenance, which includes keeping the ways oiled with way-oil.

Other machines like the Kearney Trecker 2H and the Hendey lathe still have cutting oil in them as they are used less often and are typically run much slower, so the oil is more beneficial.
 
I think it depends also on whether you are a hobbyist or a commercial shop. Water based coolant doesn't like to sit for long periods of time. Shit grows in it and it can really stink. I use cutting oil on all my lathes and water based coolant on my horizontal saw. I use a portable mist system on my mills and a permanent mist system on my vertical band saw. So it depends. Also I never use high speed cutting like a commercial shop must. It's too expensive for low volume work. Old fashioned low speed, high DOC and HSS tools is the low $ way to go, so in that case cutting oil is your friend.
 
You guys can say what you want regarding water based coolant in a machine like a K&T mill, but unless you have dealt with an old machine that someone thought it was ok to run soluble oil in, you're dreaming. I know John posted a K&T ad several years ago saying it was ok, but unless you plan to be absolutely anal about maintaining the machine my advise is don't do it. You may not like cutting oil- nothing personal, but "too bad" - it works. If you consider nothing else- look at the design of the coolant sump- how are you going to keep it clean and skim the tramp oil off or clean it out??? Kinda hard to get in there huh? One of the main reasons that coolant goes bad sitting in a sump is anaerobic bacteria- an oil film makes those little bugs very happy. Different deal when you have a separate coolant tank. Dan
 
For a context of using old machines for personal use, what would be a (relatively) safe and (relatively) affordable oil option?
 
You guys can say what you want regarding water based coolant in a machine like a K&T mill, but unless you have dealt with an old machine that someone thought it was ok to run soluble oil in, you're dreaming. I know John posted a K&T ad several years ago saying it was ok, but unless you plan to be absolutely anal about maintaining the machine my advise is don't do it. You may not like cutting oil- nothing personal, but "too bad" - it works. If you consider nothing else- look at the design of the coolant sump- how are you going to keep it clean and skim the tramp oil off or clean it out??? Kinda hard to get in there huh? One of the main reasons that coolant goes bad sitting in a sump is anaerobic bacteria- an oil film makes those little bugs very happy. Different deal when you have a separate coolant tank. Dan

All three of my K&T mills have gear type coolant pumps.. Gears work much better with oil than they do with water...Mine are happy and I can leave them unattended for months and they are still happy with oil.. No stink factor, no worries about water getting into precision fits or places where gears and bearings play...Oil is pretty much plug and play and as Dan said, unless you have a program like plants do to constantly monitor and skim the tramp oil off of your soluble, you are going to have problems....K&T tool and die mill specifies light bodied cutting oil for die work....Ramsay 1:)
 
For a context of using old machines for personal use, what would be a (relatively) safe and (relatively) affordable oil option?
You are not giving enough information to give you any realistic help. But assuming you are just turning/milling 1018 with hss cutters probably the cheapest and easiest to get is threading oil ( Ridgid or equal ) you can get it at most hardware stores..
I use a Mobil oil cutting oil, it has a little less smell and smoke than the threading oil, when taking heavy cuts. I know one shop that uses a hydraulic trans oil that is semi- syn. Says it's cheaper, and has a higher flash point.
 
Dark Rigid pipe threading oil will work just fine, BUT it will create a gummy residue and make your machine look like a junk pile, as it will stain the paint. 1 gallon or 5 gallon containers of Mobil 466 are available from Zoro, many times with free shipping, or you can buy it from a local oil jobber. Nice thing about the Mobil cutting oils is many of them are clear, not dark so you can see your work.
 
I guess I'm old fashioned. I like the smell of cutting oil on hot steel. I also like the smell of tarred hemp in an old fashioned rigging shop. I would however, not use heavy sulfurized gear cutting oil (threading oil). It creates a difficult to clean scum for very limited benefit. As a tip, industrial strength truck tarp cleaner dissolves that scum without paint damage. I also do not use flood coolant on any of my mills. I find that mist cooling is much better because of chip removal preventing re cutting of chips improving cutter life substantially as well as improving the finish. On the rare occasion when cutting oil is required, I use a small tin and a brush. Now, when is comes to cutting threads or reaming, I use Tap Magic. It is superb, economical and does not make a mess. If I am using a rotary burr on aluminum, I use lamb fat and candle wax to prevent chip welding on the burr.
 
I've used a Trico mister unit for years on both my bed mill and manual lathe. On the mill it gets used all the time, lathe maybe 30% of the time. Using Trico's synthetic Micro-Drop cutting oil. It's clean, non staining and doesn't gum up unlike their veg based stuff. Definitely a cleaner setup on more open machines than water based coolant or oil.
 
Water soluble oil will really trash a hardinge, they advise using only straight cutting oil, I use screw machine cutting oil, its fairly thin and doesn't smoke as bad as cheap thread cutting oil.
I still use water soluble in my surface grinder and band saw. That type of oil is not good for you, it will go through your skin, if you can taste it, you are really getting a dose!
 








 
Back
Top