[nicad]

I have been milling aluminum with misting WD40 as coolant, which has been working very well so far, but after dumping 3 gallons of WD into thin air (i know a lot of it goes with the swarf) within a year, I am noticing amounts of oil building up on other things in the shop (the mill is not enclosed, which is NOT an option)... so I am wanting to get away from mist coolant and goto flood cooling with partial enclosure ("splash shields"). I already have a coolant pump (the little $100 unit from mcmaster), and I am putting a tray (the 45Liter "low" containers they sell for under-bed storage) which is plastic, but seems to be pretty robust.
My question: should I run a coolant like Kool Mist 78 which they say can be used for flood cooling? Or is there a better coolant?

Any information will help.
Thanks-
Colin

[Ken_Shea]

There are pro's and cons to both the synthetic as well as the water soluble oil type. with aluminum it is mostly about flushing chips so I stick with the synthetic, stays real clean, does a good job, if I need more lube I mix it a bit stronger. I think the water soluble oil may do a better job of lubricating but it can get real nasty, may last longer since only the water evaporates so all you have to do is add some water to replenish.

I have been very pleased with the "Universal" brand synthetic lube/coolant.

Sorry, lost the link to it, need to get some my self.

Ken
.

[nicad]

Alright-- I got a gallon of the universal synthetic lube.
It says to cut it 1:10 with water.

Now, should I use distilled(purified??) water, or is tap water OK?

[Geof]

I have been milling aluminum with misting WD40 as coolant, which has been working very well so far, but after dumping 3 gallons of WD into thin air (i know a lot of it goes with the swarf) within a year, I am noticing amounts of oil building up on other things in the shop.... Colin

Whatever coolant you use remember one of the things in your shop that you will NOT SEE the oil building up on is the inside of your lungs. Misting, whether you use something like WD40 or a soluble coolant, is remarkably good at creating microscope droplets which take a long time to settle and are small enough to get into your lungs. You might want to consider some sort of air extraction system over the machine or be very diligent about wearing a surgical grade respiratory mask practically all the time in the shop.

[nicad]

Geof-
Very good advice... and is yet one more reason I am getting away from the misting setup.


About the tap water -vs- distilled water. I have everything setup and ready to use, and am ready to fill up the reservoir... I'm chomping at the bit to do so, but I do not want to mess anything up by using tap water if that is a no-no. But if distilled water is not required then I don't want go overboard with buying 5 gallons of it. (..but if that is what's required, I will do so!)

anyone know for sure? Experience? does it make a difference?

[Ken_Shea]

Distilled is perfect, tap is just fine especially if it is not hard well water which will still work but you might mix it a bit less diluted.

[Geof]

Distilled is perfect, tap is just fine especially if it is not hard well water which will still work but you might mix it a bit less diluted.

Or collect rainwater. Which, unfortunately, has not been in short supply down around your way and further south lately.