[Jin Park]

Hello.....

We bought a used okuma CNC machine...then filled up coolant tank...after 2-3 months, it became contaminated as shown in the picture... some of my coworkers says that it might be caused by bacteria and others say that it was the oil or the lubricant mixing in with the coolant.
Please tell me whats wrong and how i can solve the problem.

thanks..

Attachment 243322[ATTACH=CONFIG]2Attachment 24332443322[/ATTACH]

[ifixcnc]

What coolant did you use? Blazer is a good choice. A skimmer will pull the tramp oil out. The bacteria live between the tramp oil and coolant.

[underthetire]

Improper mixing of coolant -IE just putting in water without any concentrate
Cheap coolant
Not getting the tramp oil out.

[Jin Park]

Thanks..for your reply... my company has 4 CNC Milling machines and all use same brand..'NOCOSOL' ... and only 1 machine has such a coolant problem...
and that machine has little hydraulic oil leakage. it drop onto the coolant tank..so i fixed that.. is it possible oil with coolant make that contamination?.

[Algirdas]

was the coolant system cleaned before filling up with new coolant?

[ifixcnc]

Algirdas makes a good point. The leaking oil sitting on top of the coolant makes a place for bacteria to grow. If you have all the leaks fixxed and your coolant is OK in other machines, pull the tank and and steam clean it to remove any old contamination then you should be OK. A skimmer is cheap and works well.

[Jin Park]

thanks for all the infos..you guys gave me. .. first of all.. i just filled up coolant without cleaning. it's my first cnc machine so i didn't know that and no one told me. this morning one man who supply all the coolant an Lubs to my company stop by and checked it...he said coolant and oil and bacteria all mixed.. and suggested me 1) drain all coolant 2) clean it with cleaner(he will give me, mix 2% with water and run over 24hour it will clean the tank) 3) fill up the tank with new brand coolant(Semi-Syn coolant) and new brand way-lube 4) install skimmer.. ... but it will takes a while to finish all the things.. and i will be off for next 2 weeks..so maybe i have to ask someone else to do this job for me....thanks again gentle men...