Took me 6 months to figure out I was using the wrong coolant concentration

I was running a Haas VF-2 at my shop in Charlotte last year and kept having these random tool chatter issues on aluminum parts. Swapped inserts, checked speeds, tightened everything down. Nothing fixed it. Then one day the coolant guy comes by for our quarterly refill and tests our mix. Turns out I was running at like 3 percent concentration instead of the recommended 7-10 percent. The gauge on my mixing barrel was busted (typical, right?) and I just assumed it was accurate. He showed me how the low concentration reduces lubricity, which causes that harmonic vibration. After he dialed it in properly the chatter vanished on the very next part. Has anyone else had a coolant issue that turned out to be something totally obvious you overlooked?

3 comments

3 Comments

blake69121d ago

...and then the coolant guy shows up and saves your bacon, right? I had a similar thing with a grinder where it kept burning the workpieces, turned out the coolant pH was way off because someone put tap water in the tank instead of distilled. Your mileage may vary but now I test the mix every single Monday morning with those little refractometer things, just to be safe.

sam_murphy3921d ago

@blake691 that bit about tap water wrecking the coolant hits close to home. I've seen guys top off machines with whatever's from the hose and then wonder why the parts come out burnt. So here's my question: what do you do when the refractometer shows the mix is off but the pH strips look fine? I had a situation where the coolant looked perfect on paper but was still causing rust spots, turned out the bacteria count was through the roof and the strips just weren't catching it.

troy83221d ago

3% is insane man I can't believe it ran at all without smoking the whole machine. I had almost the exact same thing happen with a Mazak where the mix was way off but my pH strips looked fine just like you said.