Cast Iron Coolant Maintenance

[dww6eng]

I have a continuous cast iron job in one of my vertical mills. I am curious to hear if anyone has any tips to making the coolant last as long as possible?

As of right now I have an MP Systems CDR but the coolant still gets dirty fairly quickly. I plan to add a NexJen oil skimmer in the near future to hopefully pull more contaminants and oil out of the tank.

Is anyone cutting cast iron and not dumping their tank every 3 months?

 

[BT Fabrication]

Define dirty? as is color? or is the filter system not handling it down to 3 micron like it should?

have you sent used coolant samples to be tested?

 

[dww6eng]

The color has changed. It is now a light brown vs the original white. The CDR filter removing the particles is hard to tell. The coolant visually seems to not have noticeable particles in it to the naked eye. However, in the MP systems product guide it suggests that the system removes 1 quart of material a day, or about 5 gallons a month. I get less than half of that. I put in an email to MP to touch base with them about it. I also sent a coolant sample off to be tested, just waiting on results.

When I get to the shop in the morning the coolant has a layer of what appears to be a mix of oil and foam floating on top. I suck as much as I can up with the shopvac before turning the pumps on. It also has developed a musty smell that stinks the whole shop (I am a small facility, roughly 3300sq ft). Side note- tool life has steadily declined as well, I do not know if this is related.

It seems this current mix has lived out its lifespan and will most likely get dumped over the weekend. I would just like to know what else I can do to prevent this.

For sake of argument the coolant is Oemeta Novamet 900.

 

[BT Fabrication]

I use the same stuff.
I wonder how clean the castings are for it before it goes in the machine. Novamet 900 just works well with alloys. probably not the best thing for cast iron as it likes to clean the hell out of whatever it touches. and willing to bet the cast iron isn't all that clean on the outside. the filter probably is working taking out the larger particles. but the casting dust it wont strip as its most likely sub micron and don't want to filter that fine as it would strip other additives out of it and oils.

I would probably be not using that exact coolant if cast iron is a regular job and put a cheap coolant into it if needed.

cant cut the parts dry? cast doesn't need coolant, seen others who have massive filters in the coolant systems to prevent this and an additional filter system once a month that pulls it down in a 1 micron filter to clean it all.

 

[dww6eng]

They are decently clean relative to other cast iron parts I've delt with. They are heat treated so oils are not present. I also wipe them down as best I can. Since you know Novamet, I check with test strips and refractometer. Test strips look great, right in range. I run about 8% concertation to keep bacteria from growing and for lubricity. The musty smell isn't terrible. Its noticeable in the shop, but it's far from unbearable.

I plan to run one more sump full of this because I don't have time to get another coolant on order right now and I have a lot of it, then I will explore other options and be prepared for the next swap. Maybe invest in some equipment to making changing the coolant easier.

I wish I could. I have to drill and pocket some deep holes that require the thru spindle coolant. I brought that up to the engineering team at the tooling vendor and they strictly said no. Also, as stated before these are heat treated (32 to 35Rc) so that adds another level of difficulty.

I appreciate your replies.

 

[Blaser Swisslube]

As a general rule of thumb, we follow these "7-points of success" that may help you prevent this.