Question about coolant concentration meters

Just read a study from a machine tool magazine that said 80% of shops run their coolant too rich. I always thought more was better for tool life. Anyone else check their mix with a refractometer regularly?

4 comments

4 Comments

fisher.jessica1mo ago

Yeah, I was surprised by that too when I first started checking. I use a cheap refractometer every Monday morning now. Found out I was running at like 12% when 8% was plenty for my aluminum work. What concentration are you aiming for?

jamiehayes1mo ago

Thought it was all marketing until my own refractometer showed similar over-concentration.

wesleyfox1mo ago

That study lines up with what I've seen. More coolant isn't always better and can actually cause issues like residue and skin irritation. A refractometer is the only way to know for sure what you're running.

sanchez.ivan27d ago

That point about residue really stuck with me. I read a forum post where a guy kept getting a white film on his parts, and it turned out he was just mixing his coolant way too strong. A simple refractometer check fixed it.