kool mist turning aluminum parts black

[metalmayhem]

I did my research and koolmist states many times over that their 78 cutting fluid is safe for aluminum and does not cause corrosion . I grabbed 2 jugs to try and mixed the 4oz/gal as recommended for flood . One thing that stood out was that it didn't have much smell which is a good thing . The second thing that stood out is it made a days worth of aluminum parts brown , purplish and blackish . I didn't notice this at first but after leaving a part on the mill for an hour it was extremely discolored . I went through the other parts and they are all trash . I always rinse my parts then lean them to drain off the water , so the parts that were rinsed immediately weren't as bad . Since these are long running parts the portions that were freshly machined vs the areas that were sitting is evident in the discoloring .

The recommendation I got from kool mist was to use purified water . In 30 yrs of machining I have never had to use purified water and I'm not about to bring in 60 gallons of purified water to dilute these 2 jugs , well a jug plus some now .

Next message he flat out stated my water is too hard , actually it's to the contrary . the water here is super soft which if anything causes excessive foaming under high pressure systems .

Then he goes on to state that kool mist isn't for every machine operation . It says that it is safe for aluminum and that it can be used as flood coolant . I am cutting aluminum and I am using it as flood coolant , what portion of this isn't correct ?

As it stands I'll need to drain my mills and go back to what I know works and is safe for my aluminum parts and my mills . This is going to be an excessive amount of coolant to save for my saw , but it'll get used up eventually as long as it doesn't rust the crap out of my saw .

What pisses me off throughout my conversation is that everything in this is the fault of something else , mostly the water . I have used so many brands of coolants throughout the years and they all work as stated , with the same water . And having to use distilled water or purified water with machine coolant is flat out ridiculous . Not only is it inconvenient it is not cost effective when I am pouring 15-20 gallons at a time . If I was a weekend warrior then I could deal with it , but since this is my livelihood then this is nothing but a set back

I know this may sound like a rant and I suppose it is , but if it helps to prevent someone else from having the same problem then good . I've done a lot of reading since this issue and though there are guys using this successfully with aluminum , there are guys who have had the same problem

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[mactec54]

I did my research and koolmist states many times over that their 78 cutting fluid is safe for aluminum and does not cause corrosion . I grabbed 2 jugs to try and mixed the 4oz/gal as recommended for flood . One thing that stood out was that it didn't have much smell which is a good thing . The second thing that stood out is it made a days worth of aluminum parts brown , purplish and blackish . I didn't notice this at first but after leaving a part on the mill for an hour it was extremely discolored . I went through the other parts and they are all trash . I always rinse my parts then lean them to drain off the water , so the parts that were rinsed immediately weren't as bad . Since these are long running parts the portions that were freshly machined vs the areas that were sitting is evident in the discoloring .

The recommendation I got from kool mist was to use purified water . In 30 yrs of machining I have never had to use purified water and I'm not about to bring in 60 gallons of purified water to dilute these 2 jugs , well a jug plus some now .

Next message he flat out stated my water is too hard , actually it's to the contrary . the water here is super soft which if anything causes excessive foaming under high pressure systems .

Then he goes on to state that kool mist isn't for every machine operation . It says that it is safe for aluminum and that it can be used as flood coolant . I am cutting aluminum and I am using it as flood coolant , what portion of this isn't correct ?

As it stands I'll need to drain my mills and go back to what I know works and is safe for my aluminum parts and my mills . This is going to be an excessive amount of coolant to save for my saw , but it'll get used up eventually as long as it doesn't rust the crap out of my saw .

What pisses me off throughout my conversation is that everything in this is the fault of something else , mostly the water . I have used so many brands of coolants throughout the years and they all work as stated , with the same water . And having to use distilled water or purified water with machine coolant is flat out ridiculous . Not only is it inconvenient it is not cost effective when I am pouring 15-20 gallons at a time . If I was a weekend warrior then I could deal with it , but since this is my livelihood then this is nothing but a set back

I know this may sound like a rant and I suppose it is , but if it helps to prevent someone else from having the same problem then good . I've done a lot of reading since this issue and though there are guys using this successfully with aluminum , there are guys who have had the same problem

Sulfur and chlorine cause that to happen, which is a common ingredient in coolant unless you get some quality coolants that are Sulfur and Chlorine free, it will get black and corrosion on some grades of aluminum not all grades of aluminum are affected by these chemicals

[metalmayhem]

I only machine aluminum and I avoid those elements in my coolant . It doesn't look like the kool mist has any of that . I do have some chlorine from the tap water but thats never been a problem and that chlorine will dissipate in around 24hrs anyhow . I usually do my research before adding anything new , and kool mist is supposed to be safe for aluminum , and no corrosion , or so they claim . The mess that was made to my parts was pretty rapid and is consistent to another coolant that I ran once before that did the same thing . That time I grabbed the wrong bucket # and it was not meant to be run on aluminum by any means .

I drained the mills again , cleaned them up , then switched back to a coolant that I was running up to a few yrs back and things are good again . The kut-sol that is in the machines right now is a good coolant and decently priced , but it will go skank in the summer heat . Otherwise I'd stick with that since it's economical and works .
This will do for the time being until I get my cimcool delivered . I've always leaned towards the cimcool semi synthetics which is simply a great product , and the results are always consistent . Plus that stuff has great corrosion inhibitors even at a low reading .

I'll have to look at this mess with kool mist as an experiment gone seriously wrong and use the remainder for my saw