Cutting Fluid - What do you use?

[TheShaman]

I think we can all agree that cutting fluids are a necessary tool in a DIYer's arsenal, making the boring metalworking/machining stuff so much easier...

People have been using from WD40 to purpose-made products like Tap Magic and alternative ones like coconut oil, but what's your favorite?

[Cal Weldon]

What are you cutting?

[TheShaman]

Mostly aluminium.
My favorite so far is coconut oil (an idea I got from a friend) which is easy to get, cheap and beats stuff like WD40. Haven't tried specialty products like Tap Magic though.

[Cal Weldon]

For aluminum we use either plain water or the milky oil-water mix.

[TheShaman]

Originally Posted by Cal Weldon

...the milky oil-water mix.

Hmm, yeah, I can get that sort of stuff locally and it's not expensive either.

By the way, before going for the coconut oil idea I had a look around and was surprised to see that it's use as cutting fluid is documented in the literature (e.g. here). Other people suggest groundnut oil or even sunflower oil based products.
I'm not sure about the long term effects such residue can have on the metal, though.

[djQUAN]

I use WD40. And once used IPA (which seemed to work fine) when I didn't want any oily residue on the workpiece.

[Cal Weldon]

Originally Posted by djQUAN

IPA

You used beer?

[KatieandDad]

WD40. It's cheap and comes in handy can with straw nozzle.

[Juergen Knoop]

for aluminium I was thaught to use spiritus. Of cause there may be a safety issue...

[mr_push_pull]

first cutting lubricant I ever used was regular soap.
when manually tapping threads I use plain 10W40 motor oil. it does an incredible job.