We had a door to door salesman talk me into a vegetable oil based
coolant about 15 years ago. He actually gave me the first gallon to try
out. Since, at that time, most of our coolant was used with the brush
dip method it lasted quite a long time. Several months after we started
using it I notice that the machines were getting a sticky residue on
all the surfaces the coolant evaporated from. Almost nothing would cut
thru the gooo so we stopped using the crap and have been scrubbing away
at the vegetable oil based varnish ever since. It did have very
pleasant odor when it got really hot. It smelled like bread baking. Our
current flush coolant is Blazers and we have been on the same drum for
about 5 years and that is in four or five machines. I'd suggest using
coolant that is intended for metal working. BTW The petroleum based
coolant we used, in small amounts, has no sulfur odor though it tastes
bad when you get it into our mouth. It comes from Champions Choice in
Fullerton,CA and their special difficult to machine oil is fantastic. I
use it when threading 304 SS and O-1 tool steel and I can make threads
you would thing were rolled. Leigh@MarMachine