Coolant choice for brass parts giving me trouble, suggestions?

I've been running brass on my CNC lathe and the coolant I'm using seems to cause residue. It builds up on the tool and parts, making cleanup a pain. I switched to a water-based mix but it still leaves a film. What do you guys use for brass to keep things clean and smooth?

3 comments

3 Comments

barbara_adams1mo ago

That film from the water-based mix is so normal though. Is the residue actually hurting the finish or just making extra wipe-down work? Brass is usually the easy metal to run, I've never seen gunk from coolant be a real issue. Maybe it's not the coolant's fault but something else in your setup.

thomas_hall1mo ago

Tbh, have you ever had brass get sticky from a bad batch of coolant? It can definitely mess with the finish if the residue builds up.

reese_ward501mo ago

Yeah, Barbara's note about brass being the easy metal rings true, but I've definitely dealt with that sticky coolant film (it made everything feel gross). In my case, the fix was dialing back the additive ratio in the mix, which cut down on the residue. A good system flush with clean water helped clear out the old gunk too (just don't forget to dry things after). That stickiness never ruined the parts for me, but it did add an extra cleaning step every time.