80% lower finishing

[RandallZ]

You shouldn't actually need cutting fluid for aluminum. But, yes, wd40 would work as cutting fluid...it's basically fish oil. I have also used Canola oil, but you have to clean it up before it gets gummy which happens pretty quickly.

[Caleb]

Just buy cutting oil, I doubt it's that much more than wd40. But, wd40 will work if that's all you have.