I have been manually skimming my coolant tanks, and as you can guess, that sucks.
I bought a coalescer for one of my mills to test something more effective, and less hassle. It worked well to skim the free oil from the coolant, but it there is still a brown layer of partially emulsified tramp oil that it isn't separating. I expected the coalescer to strip the oil from this mixture, but it isn't. It passes the coolant through the coalescing media, and just mixes the brown layer back in. The brown layer disappears after skimming for a while, but when I shut off the unit, the brown layer floats back to the surface within 15 min, and covers the machine sump.
My question is whether my expectations are realistic. Do any of the coalescers strip tramp oil from well mixed layers?
The coolant is Trim E206. I'll refrain from naming the coalescer for now, because I would like to know if any of them are effective at stripping tramp oil from mixture, rather than just separating free oil from the surface.