# mill and lathe.....what should I use for coolant/lubricant?



## Firstgear (Dec 31, 2018)

Both machines come with pumps located in the base....what should I use for coolant/lubricant?  Most of my work will be on aluminum.

Looking at what others have used I see a lot that spray WD40 on the area or Tap Magic Aluminum....some have a mister that they have made...  I would appreciate comments...also if using WD40 or Tap Magic, how often is it being applied?


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## Bob Korves (Dec 31, 2018)

The pumps in the bases run "flood coolant" setups, squirting water based coolant (and sometimes, but rarely, cutting oil) directly onto the tool and work.  It works well, keeps things cool and lubricated.  Beyond that, flood coolant can be a real mess in the home shop.  Many of us use spray or brush on cutting fluids, manually applied, or mister units that spray a light mist of water based coolant and air onto the work.  A lot of work is simply cut dry.  Which is best?  Depends on what you are doing, what kind of machines you have, how neat and clean you think a shop should be, and how important good surface finishes and parts finished to an accurate size are to you.  There are lots of trade-offs in choosing which way to go, and really, all of the various options have their benefits as well as their problems.

A better description of what you will be doing, how often, how important speed, accuracy, and surface finish is, and how much cost, extra effort, and cleanup you are willing to do to get there, would help us help you make those decisions.


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## Firstgear (Dec 31, 2018)

I want to keep them clean, thinking about buying a $20 shop vac from ACE hardware to suck up the pieces machined off....saw that a few people use rubbing alcohol......any comments on the alcohol?


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## Bob Korves (Dec 31, 2018)

Firstgear said:


> I want to keep them clean, thinking about buying a $20 shop vac from ACE hardware to suck up the pieces machined off....saw that a few people use rubbing alcohol......any comments on the alcohol?


Rubbing alcohol would cool the work, but nothing else.  I would hate the smell of it.


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## ttabbal (Jan 1, 2019)

I've been happy with kool-mist with a cheap sprayer. The smell is much nicer than burning oils and such. I use a shop vac to clean up the chips. 

After using water based coolants like kool-mist, I like to wipe the machine down with way oil to make sure to keep rust down. I can't say that it is an issue for sure, but it can't hurt.


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## shooter123456 (Jan 1, 2019)

I have used WD-40 for aluminum and motor oil for steel for a while.  Recently I started using kool-mist with a mister I rigged up from an old RO filters remains.  I like it for aluminum milling, but finding the right balance between coolant to lubricate and cool, and too much causing the chips to stick has been a little tough.  You can use kool-mist for flood coolant I believe, but I haven't done that.  I think WD-40 works very well for aluminum lubrication but I am not sure it does all that much for cooling.  It also smokes a lot which I don't love.  Motor oil helps lubricate on the lathe when I cut steel, and maybe cools a little, but I can't imagine much.  It stinks and smokes a ton, so I use it with a fan blowing the smoke away and with the garage door open.  I have trouble imagining there isn't a better solution for that, but it works well enough when I need it.


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## PHPaul (Jan 1, 2019)

I use WD-40 on aluminum and various oils on steel and had to find a way to deal with the smoke and smell, as I work mostly in my basement.

I wound up taking a computer muffin fan, mounting it to one side of a box about 6x6x3 inches.  On the other side of the box, I mounted a short piece of 4" PVC S&D (sewer and drain) pipe.  

A length of aluminum dryer exhaust pipe and a couple of 4" swivel elbows run from the fan to a sort of dryer vent arrangement I spliced into the nearby basement window (which long ago got replaced with plexiglass thanks to my lawn mower  )  It's powered by a small 12v power supply I had laying around.

The fan box is mounted to a spare magnetic indicator mount I had laying around so I can set it up for either the lathe or the mill.  Works quite well.


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## Tozguy (Jan 1, 2019)

In your situation i would avoid using water based coolants because of the mess they can make.
Until you have to push for high production rates, use some of the recommended cutting fluids for aluminum and apply by hand. It will be obvious with time if the flood  coolant systems on your machines ever become worth the extra trouble to use.
Misters and maybe just some air could be options. Be aware of the fire hazard when using some fluids. Absolutely avoid breathing any of the fluid that gets in the air around you. Always consult the safety data sheet for any product you use.
Do not use alcohol of any kind.
Some aluminums are very difficult to turn cleanly and gum up the tool even with a well chosen cutting lubricant.


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## P. Waller (Jan 1, 2019)

I work in a small machine shop, we have 6 mills and 5 lathes of varying sizes, all use flood coolant except when milling with a facemill when the manufacturer recommends doing it dry.
In aluminum materials water soluble flood coolants are excellent.

Dry face milling steel


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## ddickey (Jan 1, 2019)

I used to mix up some doluble oil in a spray bottle and just spray it on when needed. Worked fine.


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## shooter123456 (Jan 1, 2019)

A little tip that I took too long to learn... If you are going to use WD-40, get the gallon jugs and put it in a spray bottle.  You will get much more WD-40 for a lot less.


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## wrmiller (Jan 1, 2019)

Second vote for WD-40. Although when I installed my Fogbusters I switched to A9. It even work resonably well for light work in steel (and I don't have to change fluid).


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## Bob Korves (Jan 1, 2019)

shooter123456 said:


> A little tip that I took too long to learn... If you are going to use WD-40, get the gallon jugs and put it in a spray bottle.  You will get much more WD-40 for a lot less.


You can also buy kerosene, by the gallon or in bulk, for far less money, and it will work just about the same.


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## kd4gij (Jan 1, 2019)

I ran lathes and mill with flood collant where I used to work. I would at home if I had the machines that where setup for it.
On the lathe just setup with a drip at the tool and it won't make any more mess than a mister. On the mill drip just ahead of the cutter.
Just because it is called flood coollant doesn't mean you have to flood with it.


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## Firstgear (Jan 1, 2019)

lots of good comments....I will try a few of them....see what I like the best for my situation.


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## kc1dmf (Jan 2, 2019)

Bob Korves said:


> You can also buy kerosene, by the gallon or in bulk, for far less money, and it will work just about the same.


I've heard of using kerosene as a lube/coolant on glass, but, given its flash- and autoignition-points, how do the temperatures generated by milling/turning not cause it to combust? Or, is it just a matter of pouring enough over the workpiece that it never gets that hot?

(Maybe I'm paranoid, but it still seems dangerous. Either way, thanks for reminding me to check my extinguisers!)

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## Janderso (Jan 2, 2019)

I agree, flood coolant for the hobbiest is a mess. I am all in for a Kool-Mist system.
WD-40 on aluminum is incredible IMHO.


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## Bob Korves (Jan 2, 2019)

kc1dmf said:


> I've heard of using kerosene as a lube/coolant on glass, but, given its flash- and autoignition-points, how do the temperatures generated by milling/turning not cause it to combust? Or, is it just a matter of pouring enough over the workpiece that it never gets that hot?
> 
> (Maybe I'm paranoid, but it still seems dangerous. Either way, thanks for reminding me to check my extinguisers!)
> 
> Sent from my SM-G920P using Tapatalk


Flash point of WD40 is 122F  https://www.wd40.com/files/pdf/msds-wd494716385.pdf
Flash point of kerosene is 100-162F per your link  https://www.wd40.com/files/pdf/msds-wd494716385.pdf 

Both are about the same.  Both are much less flammable than gasoline.  I have not heard stories of flames caused by using either while machining.  I would not use either as flood coolant, but for small amounts I am not too concerned.


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## Firstgear (Jan 2, 2019)

Its been my opinion. and that is all, but if you take kerosene and put it on the ground, like on a concrete driveway or on steel and put a match to it, it wont ignite.  Put it with paper or cardboard and it ignites because there is something else that is flammable that can sustain the ignition.

I believe what we are concerned about is the autoignition temperature of kerosene.  That is the lowest temperature at which a mixture will ignite in the absence of spark or flame.  That temperature for kerosene is 428 deg F (220 C).  This is at atmospheric pressure, increase the pressure like a diesel engine and that temperature drops significantly.

If I had some kerosene I would demonstrate and take a video....the temperature of a lighted match is about 450 degrees F, that is the ignition temperature of dry wood and paper.

Disclaimer...I am not a scientist, take these comments with a grain of salt...my attorney advises I put that down....


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## Firstgear (Jan 2, 2019)

P. Waller said:


> I work in a small machine shop, we have 6 mills and 5 lathes of varying sizes, all use flood coolant except when milling with a facemill when the manufacturer recommends doing it dry.
> In aluminum materials water soluble flood coolants are excellent.
> 
> Dry face milling steel


you can use flood coolant because you have a door and contained area to keep the splash in.  Also you or your maintenance people test the coolant on some kind of regular basis and change it out as needed....that was how it was done when I was working....


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## P. Waller (Jan 2, 2019)

Firstgear said:


> you can use flood coolant because you have a door and contained area to keep the splash in.  Also you or your maintenance people test the coolant on some kind of regular basis and change it out as needed....that was how it was done when I was working....


Insert manufacturer Seco recommends no coolant as the inserts are not carbide, I do not know what they are, CBN, PCD?
They work well however, do not run it with the doors open (-:


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## jdedmon91 (Jan 5, 2019)

Bob Korves said:


> You can also buy kerosene, by the gallon or in bulk, for far less money, and it will work just about the same.



Yes you can but Kerosene is close to $5 a gallon here. I’ve used diesel fuel for aluminum at under $2.50 here. 


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## jdedmon91 (Jan 5, 2019)

I have a inexpensive mister, just a pain to set up for a simple job. However it does work well. I have some coolant that I got form work before I retired so I’m set. Just need to come up with a better way to easily and quickly mount it. 


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## rgray (Jan 5, 2019)

If you want to try flood coolant get a gallon of "Trim MicroSol 585XT" made by master chemical.
Can get it on amazon: https://www.amazon.com/TRIM-MS585XT...=8-1-spons&keywords=trim+microsol+585xt&psc=1

Their website: https://www.masterfluidsolutions.com/na/en-us/index.php

Mixes at 10% so a gallon makes almost 13 gallons of coolant (I mix 10oz to a gallon myself)
My manual lathe holds less than 2 gallons. So a gallon will last for years for a machine like that.
I've used other name brands (big advertising) and it went rancid and stunk very quickly. This stuff either doesn't or it just doesn't bother me when it does. I don't notice it ever having much smell.

I use it in my manual lathe, mill, surface grinder, cylindrical grinder, and cnc lathe.
I have a 5 gallon bucket on hand. 
Pretty sure I got it for $170.00 on a free shipping promo. Haven't looked for a price for a long time since getting that quantity, that amazon price sure has gone up from what I remember.


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## Groundhog (Jan 5, 2019)

I've used Trim C350 for flood cooling/lubricating my CNC mill for years. I use it on all types of aluminum and steel. Not for use on cast iron or titanium.

Use some method to insure accurate mixing ratios (like a brix refractometer - about $20). It can leave sticky/gooey deposits on the mill if mixed too heavily. Does not cause not rust if mixed properly, but may require distilled/filtered water. I've lived where I could use tap water without rusting but where I am now I must use filtered water or I get rust. I have a small, cheap aquarium air pump on a timer that bubbles for 10 minutes a couple of times a day to keep the algae & odor at bay. I use the same coolant for months (years actually) without odor that way, just toping up with water and/or C350 as needed (keeping the ratio within limits).

If I werent already set up with an enclosure I would sure give a mister and/or just air a try. I use brushed on _Tap Magic for Aluminum_ and _Rapid Tap Cutting_ fluid for steel on my lathe but will add a mister soon.


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## ttabbal (Jan 5, 2019)

jdedmon91 said:


> Just need to come up with a better way to easily and quickly mount it.




I recently bolted one to the magnetic base from a HF indicator holder. Works great. The mister had 2 mounting holes, I just drilled and tapped the mag base to match.


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## hotrats (Jan 5, 2019)

I bought a couple of these put oil/kero in one, and water soluble in the other. Keep the premix in the gallon size laundry detergent jugs that have the squeeze bulb valve caps.


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## mmcmdl (Jan 6, 2019)

Personally I wouldn't run flood coolants in a shop at the house . When the coolant goes rancid , that **** stinks like a crab shell filled dumpster . I don't miss that smell one bit ! For aluminum , the WD-40 is simple , brush it or spray it . I hate misters at home also . Oil or tap magic for steel and WD-40 for alum . 

Watch anything that will flash , especially if you smoke !


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## MonkMan (Jan 10, 2019)

Great Post, Thanks


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## jdedmon91 (Jan 12, 2019)

ttabbal said:


> I recently bolted one to the magnetic base from a HF indicator holder. Works great. The mister had 2 mounting holes, I just drilled and tapped the mag base to match.



Mine is set up the same way. But I’m not happy with setting it up on the mill. 


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## jdedmon91 (Jan 12, 2019)

mmcmdl said:


> Personally I wouldn't run flood coolants in a shop at the house . When the coolant goes rancid , that **** stinks like a crab shell filled dumpster . I don't miss that smell one bit ! For aluminum , the WD-40 is simple , brush it or spray it . I hate misters at home also . Oil or tap magic for steel and WD-40 for alum .
> 
> Watch anything that will flash , especially if you smoke !



My coolant mix I use in the mister is over 2 years old. The way I keep it fresh is two things a sealed container and some household cleaner to keep the bacteria down 


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## starr256 (Jan 17, 2019)

As a hobbyist doing one off, smallish pieces on either brass, aluminum or mild steel, I have always been perplexed on the use of coolant. The skilled machinist I consulted (he understood my environment) recommended two things. (1) don't bother with water solubles as they are messy, requiring significant cleanup effort to keep things from rusting and (2) use mineral oil and brush it on. But I am still unsure of when to use the mineral oil.


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## rherrell (Jan 19, 2019)

I don't use anything with carbide except the finish coat, then I brush on a light coat of cutting oil. With HSS I brush on oil every pass.


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## Downunder Bob (Jan 23, 2019)

I originally set up using flood coolant with a popular soluble oil mix. But found it goes off, turns to a sticky jelly and stinks. I phoned the company and theys aid that will happen if your not using it every day it needs to be aerated, to stop it going off. I have recently drained my system and planning on replacing it with Inox MX3 

I've been using it in spray/squirt bottles and very happy with results, No rust, excellent cutting fluid for Al, steel and S/S. Haven't tried anything else yet, but that is about all I use.


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