Re: [CAD_CAM_EDM_DRO] Way Oil? Mobil Vactra #2

hllrsr@... wrote:

> Is anyone currently using this as a coolant? If so, how bad is it for
> smoking?
> At work we have been running Push Trunnions for Cat dozer blades (7.5"
> stress relieved 4340, .250"cut) and the water based coolant we now use
> turns the lathe into a smoke machine!

But, most of that 'smoke' is really steam, a cheap and relatively harmless
vapor. It is also a fantastic substance for the removal of heat! Oil has
a MUCH lower heat of vaporization, meaning a pure oil 'coolant' would
need to vaporize about three times the volume of oil to carry away the
same heat. The specific heat of oil is also lower than water, so you end
up either running a lot hotter, flowing much more coolant through the
work zone to remove the heat, or vaporizing even more oil to cool the
work and tool. GM had 2 machines that made rear axle parts that they
found pure oil coolant was the ideal coolant/lube. The problem was
that it turned the entire area of the factory into a "slip and slide zone"
so workers literally couldn't go near there without falling down! A few
weeks later, the workers all started transferring out of that area because
they were all sick with lung problems. GM tried all sorts of stuff, and
had plastic curtains surrounding the machines, HUGE air scrubbers
mounted on gigantic funnels sucking up all the air around the machines,
etc., and still didn't have the problem under control. They finally gave
up and did more research, and found a synthetic coolant that would
give the same results without contaminating the entire shop, and with
much lower disposal costs, too. This was in a Metalworking Digest,
or some magazine like that, about 2 years ago.

Jon