Hi All,

I live in the AZ High Desert and it is very low humidity (a bit high
at 31% at the moment) all year round. I have to replenish the water/
oil mix regularly as the water evaporates out pretty quickly. I was
about to order some more soluble cutting oil and thought I would ask
here first.

I am wondering if a straight cutting oil like Mobil 404 would last
longer, maybe indefinitely. I mostly cut aluminum on mills and lathes
so do not want any staining after machining.

Anyone have some low-cost favorite cutting oils?

Thanks

Dave