Nope - don’t try mixing oil and water in the saw. The blade
constantly agitating oil around will act much like a milkshake machine
to emulsify the oil and the water. You risk ending up with mayonnaise
in the tank.
Another caution is don’t use vegetable oils. Having run out of oil I
once tried an emergency mix of olive oil and mazola. Not only did the
stuff generate an amazing fog inside the saw case (theatre fog-effect
machines use -or used- atomized oil), but it also dried into the most
obnoxious thick sticky varnish all over the inside of the saw that
took hours and hours of scraping to remove.
I presently use Shell “Pella.” It’s thin, runny, slightly thicker
than kerosene and has just a bit of odour but not much. I actually
prefer Shell “Tellus” which is marginally thicker, about like cooking
oil, and has even less odour, but the difference is minimal, the
prices are about the same, and the dealer didn’t have it in stock when
I needed it.
Unless you’re cutting stone on an industrial scale, what you’ll save
in improvising with cheaper cutting mixtures is not likely to be worth
the bother and complications that may ensue. If you want to economize
on oil put a brick in the reservoir.
Cheers, Hans Durstling Moncton, Canada