Stop using coolant concentrate straight from the drum, it's ruining your tool life

Ngl I keep seeing guys at this shop near Denver just dumping full strength coolant into their sumps and adding water later. After 3 months of watching their end mills burn up I finally showed them my refractometer reading from their tank vs mine. Theirs was at 12% concentration when they thought it was 6%. I run a pressure washing rig on the side so I know how bad mixing things wrong can mess up equipment but this was next level. Has anyone else caught shop guys doing this or am I the only one checking with a refractometer every week?

2 comments

2 Comments

viola_butler1d ago

I was reading in Cutting Tool Engineering a few months back that shops that don't check concentration can lose up to 30% of tool life just from running too rich. The article said refractometers are like a hundred bucks and can save you ten times that in carbide alone. Saw a coworker at a shop in Phoenix dump straight coolant in once and he swore it was fine til the foaming got so bad it overflowed onto the floor. It's wild how many guys think "more coolant" means "better cutting".

cameron_chen2d ago

Man I feel you on this. I walked past a guy at a shop in Ohio last year and he was literally pouring 5 gallons of straight concentrate into his sump like it was nothing. I told him to check his concentration and he got all defensive. Next week he was complaining about foam everywhere and his taps breaking. I check with a refractometer every Monday morning now too.