Who else has noticed coolant getting slimy faster since the heatwave hit?

I'm over at Precision Machining in Cleveland and last week I opened up my tank on the Haas and it smelled like rotten eggs. The coolant looked thick and almost milky way earlier than it should. I thought maybe I just messed up the concentration but I talked to the guy at the supply shop and he said it's been happening all over. Has anyone else's coolant gone bad weirdly fast in this humidity?

2 comments

2 Comments

daniel_rivera1mo ago

Smelled like rotten eggs" yeah that's exactly what my buddy at a shop in Akron told me. He's been running the same coolant mix for years and last month he said it turned into this thick, almost mayo-like junk in like two weeks. He thought his machine had a leak or something but nope, it was just the humidity hitting the tank wrong. Had to dump the whole sump and scrub it out. Your mileage may vary but he swore by a little blowdown air on the coolant surface after that to keep the crud from forming.

anthony_wells29d ago

Yeah I gotta push back on that "just the humidity" thing. Humidity alone doesn't turn coolant into mayo in two weeks unless your buddy was already running it way too long or the concentration was off. I've seen that same thick junk in tanks that were perfectly dry and clean, it was always bacteria or fungus starting to grow, not water getting in. The rotten egg smell is dead giveaway for sulfate-reducing bacteria, that's not a humidity problem at all. Air blowdown on the surface helps keep oxygen in the mix which kills the anaerobic bugs, so that part I'll give him. But blaming it on humidity is like blaming a flat tire on the sun being too bright, it's missing the real cause.