coolant

[Paul Felger]

Hello all, We use Trim coolant at our shop, and I add once or twice a week, I add one mixture of coolant to the same of just water the second time it needs it, and it seems to keep the coolant number at average. My thinking is if I would add a coolant mixture every time the water would evaporate faster and would leave to much concentrated coolant. Is this true for most shops? Or is my thinking wrong?

[Paul Felger]

Also, if the coolant numbers to get to cocentated, what affect would this have on the machine or anything else?

[TK-32™]

Hi Paul,

We use a "Refractometer" at our shop. It's a gage that measures the amount of coolant in the tank. When we clean a machine and add fresh coolant we have to mix it to 8-10% coolant (this varies from brand). When the time comes to add coolant we usually add a mixture of 4-6%. This is because the coolant in the tank has more a more concentrated mixture. So if we add a less rich mixture it evens out a liltle. One thing I was told is to mix very good the coolan prior to dumping it on the machine.

[Paul Felger]

We use a "Refractometer" also, but we mix the coolant in 5gal buckets. I usually try to keep the meter at 3. I guess why I am asking this is because a friend of mine has started a new job at a shop and his lead dude told him to mix it every time. They mix it the same way, and I dont think they they use a "Refractometer" at all, I was just thinkin if they keep doing that, they would have too much coolant %%%, and if so what negative affect could that have?

[Guest]

Generally speaking, after a clean tank, an initial fill is done at the 8-10% mixture.

 

With evaporation the refill mixture can be done at a lighter mix ratio. I would suggest buying a mixing valve. You can get an OK one through MSC and other distributors as well. It is NEVER a good idea to just dump straight water into a coolant tank, you can "break" the coolant mixture.

[TK-32™]

The Lead "dude". ja ja.

 

I doubt there could be any problem to the life of the tool but I see it could be bad for the operator's skin.

[Paul Felger]

That sounds good JParis, we have over twenty cnc mills and ten cnc lathes, I have thought a good mixing valve would be a great thing to have here but the owner is a little on the tight side. I have not done any research on prices yet but most of the guys just eyeball it when mixing out of a 50gal drum. Is there a website that supports that information, such as "break" the coolant mixture? I have got some things done around here, but it took a lot to convince them!

I am surprised they use skimmers.

[Guest]

Here is a pretty thorough pdf on "coolant"

 

Linky

 

 

quote:

---

Coolant should not be mixed in the machine sump because this

practice will be the most likely cause of emulsion instability

---

Linky2

[Bjorn Petersson AME AB]

Hi guys,

 

I would refill with a lighter mixture.

I've seen both armscratching with 18% and the rust after a "friday refill" with clear water.

Use refractometer and make a weekly note to find the ideal mixture.

[Jim at Gentex]

We use Hangstefer's and always mixed to 8-10% concentration. We always eyeballed the amount and hand mixed 5 gallon buckets at a time, and checked concentration with a refractometer before adding it to the sump. This method always made sense to me and seemed to work.

 

Recently we encountered a paint adhesion problem with one of our main products, so engineering suggested lowering the coolant concentration to 4-5%.

(Since this problem appeared suddenly, my assertion was that it was a processing problem, i.e., not cleaning the parts correctly before painting, but what do I know? )

 

Anyway, we bought a mixing device that attaches directly to the coolant drum. There are a series of different sized apetures which determines the desired concentration level, so all you need to do is install the correct one for your needs.

 

You connect a garden hose from a water supply, and the coolant comes out of the device pre-mixed to whatever concentration you set it up for. We check it regularly with the refractometer and it seems to be pretty accurate. When the concentration climbs because of evaporation, I add a weakened mix instead of plain water to bring it back to correct concentration. So far so good.

 

The mixer wasn't all that expensive and was probably a good investment.