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

Firstgear

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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?
 
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.
 
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?
 
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.
 
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.
 
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.
 
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.
 
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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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
 
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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