Had a real wake-up call about coolant concentration at a shop in Cleveland last month

I was helping a friend's shop with a rush job on their Haas VF2. Their parts kept failing inspection for surface finish, and we couldn't figure out why. The owner insisted the coolant mix was fine, but I grabbed a refractometer and checked it myself. The reading was way off, almost 2% below where it should have been. We adjusted it and the next batch of parts came out perfect. How often do you guys actually check your coolant mix instead of just topping off the tank?

3 comments

3 Comments

mitchell.jesse1mo ago

Check it every Monday like clockwork. Lets you catch small problems before they ruin parts. That refractometer is the best twenty bucks I ever spent.

matthew3391mo ago

Where did you find a refractometer for twenty bucks, @mitchell.jesse?

averysullivan29d ago

Totally get that! It's so easy to just top it off and assume it's fine. But that little check saves so much time and money on bad parts. I've seen coolant go funky and ruin a whole batch because nobody checked the mix for weeks. Now I test mine every time I do my Monday morning machine checks.