Coolant Maintenance questions...

I use Hangsterfers S-388 soluble oil in my VMC.

I skim tramp oil, filter particulates and aerate. One thing I have never done is monitor and adjust pH. I do have a pH meter, and can make the measurements. What is the ideal pH? What chemicals are usually used to adjust pH in coolants?

Thanks!

All you do to adjust the PH is adjust the consentrate of the coolant mix.

Normal is 7-12% - which means that you have 7-12% oil to 88-93% water.

Cutting Aluminum's and softer stuff can handle a much lower percent - 5-7%, where some hard stuff you may want to bump it up over 12%. The hanster's website should list recommended percentages.

tc1999 said:

All you do to adjust the PH is adjust the consentrate of the coolant mix.

Normal is 7-12% - which means that you have 7-12% oil to 88-93% water.

Cutting Aluminum's and softer stuff can handle a much lower percent - 5-7%, where some hard stuff you may want to bump it up over 12%. The hanster's website should list recommended percentages.

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Um.... That's not pH, that's coolant concentration.

Talk to your coolant rep, they should have some ph adjusters that are made to work well with the coolant.

Spencer in NH said:

Um.... That's not pH, that's coolant concentration.

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Uhh, yeah - I know, dude. Just trying to help. Everyone seems to refer to the concentration as pH, So I assumed you were checking with a refractometer for correct mixture. Why would you have to adjust the acidity of your coolant?

I can't say I've ever had to adjust the acidity level of any coolant I've ever used.

Why don't you just contact the manufacturer of the coolant and see what they would recommend you do?

Or your coolant rep.


This may help. It is Hangsterfers Website.
hangsterfers

I suppose I should clarify.

I use a refractometer and maintain coolant concentration that way. But, in my surfing, I find references to pH maintenance, also.

Does anyone out there monitor and adjust pH, too, in addition to coolant concentration?

Anyone?

Beuller?

I have strips to test the ph of the coolant. I don't usually check it though unless I'm having some kind of problem or the coolant is really old. The spec sheet for your coolant should list what the ph should be. Deionized water has a lower ph than normal water so if your ph is high you can add some DI water.

The most important thing to monitor is the concentration.

Second in my opinion is the hardness. My well water is extremely hard and the minerals don't evaporate so the hardness level will rise in the machines sump. I maintain the hardness by either using Deionized water or filtered tap water. I check it with test strips.

Good luck!

We check and adjust the PH on ours, but we have a recycling system for the coolant that takes care of it.

You definitely want to discuss the PH additives with your coolant mfgr, adding the wrong stuff could be really bad.

Spencer in NH said:

I use Hangsterfers S-388 soluble oil in my VMC.

I skim tramp oil, filter particulates and aerate. One thing I have never done is monitor and adjust pH.

Thanks!

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If you do all this and are using high quality coolant like Hangsterfers...I REALLY doubt you need to worry about PH!!!

Jeff

jdj said:

If you do all this and are using high quality coolant like Hangsterfers...I REALLY doubt you need to worry about PH!!!

Jeff

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Yeaaaahhh, but..... I'm a nerd, sir. I just gots to know.

I found a VERY useful document here:

http://www.monroefluid.com/images/pdfs/mgmtguid.pdf

This document and your feedback is all very helpful. Thanks.

Spencer in NH said:

I found a VERY useful document here:

http://www.monroefluid.com/images/pdfs/mgmtguid.pdf

.

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This is an interesting link (so far, I haven't read it all) Thanks for posting it.

Jeff

I sold Hangsterfer's S388 for several years along with S500 and a lot of other of the Hangsterfer's coolants. The short answer if you maintain the sump correctly the ph will take care of itself. Charge the sump at 5% to 10% and do your make-up at 1%. You're probably doing this already if you're a "nerd".

Normal pH for your coolant should be listed on a product data sheet provided from your coolant manufacturer. Most any reputable company will test your coolant for FREE, as a service to you, if you buy their product...such as this service which is provided by Fuchs Lubricants. They will do normal routine analysis to check pH levels & alkalinity, bacteria count, fungi count, hardness, corrosion, refractometer readings & concentration, dirt loads, etc.

Simply stated, pH is the measure of the degree of acidity or alkalinity in a coolant. The acidity decreases and the alkalinity increases as the pH goes from 0 to 14. When the pH is off, there is usually another underlying problem causing this...and incorrect pH can cause oxidation & corrosion. Should you ever experience these issues, your coolant rep should be knowledgable to advise you of proper coolant maintenance basics, to avoid issue from happening again. They may even be able to provide you with some additives to correct this pH without having to dump/recharge the system. Depends on the severity of the problem, and underlying issue that caused it in the first place.

Deviation from the pH spec for your coolant is the first indicator that you have a bacteria problem. If you skim, aerate, and avoid organic contamination, it should not be a problem.

Doug

Spencer in NH said:

I found a VERY useful document here:

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This document and your feedback is all very helpful. Thanks.

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Updated link: http://www.monroefluid.com/sites/default/files/COOLANT_GUIDE.pdf

Milland said:

Updated link: http://www.monroefluid.com/sites/default/files/COOLANT_GUIDE.pdf

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Thanks, neighbor.

Spencer in NH said:

Thanks, neighbor.

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No worries. I'm getting some staining on extruded Al, and figured it would make sense to check the ph of my coolant. I got your thread when I was looking around. I've ordered a decent (I hope) ph meter from Amazon, along with some ph strips so I can cross-check.

Maybe buying my fluids from "Sam's Used Coolant and Surplus Battery Acid Depot" wasn't the best idea...

pH Level Cutting fluid pH is a very good indicators of consistent fluid quality. It represents a concentration of hydrogen ions (pH=-loh[H+]). Practically, it is measurement of fluid alkalinity or acidity. Neutral pH value is 7. Lower values represent acidic solutions while pH values higher than 7 represent alkaline solutions. Recommended pH region for water-miscible cutting fluids is 8.8-9.2. For pH value lower than 8.0 fluid is loosing its efficiency, its corrosion prohibition properties are becoming reduced and increased microbial contamination is recognizing. If the pH level becomes more than 9.5 risk for skin irritation and dermatitis significantly increases. Litmus paper provides the cheap and fast indicator of pH. Indicator stripes are dipped into the cutting fluid and it is changing color will depend on the pH level. Since the accuracy of this method is limited and it can not predict biocontamination of the fluid, another pH indicators are using more often. Electronic pH meters are more expensive, but provide more exact measurements. Their usage is standardized according to DIN 51369. This method can be very accurate (high cost pH meters are accurate up to hundredths of a pH unit), but its degree of accuracy is of little benefit for a fluid management. Titration, as a quantitative method for determining alkalinity, is also developed. Advantage of this method is that it additionally determines the rate of change of alkalinity. This helps in estimating the cause of alteration. Microbial Contamination Most common tests for microbial contamination are plate counts and dipslide test. In the plate count test, microbial growth is allowed on the plate which is than counted. The number obtained by counting is multiplied by the dilution factor and the amount of organism per milliliter is obtained. This test is standardized by ASTM D 3946-92. Dipslides method is more simple but still very common for estimating microbial population. A plastic slide coated with a nutrive gel is dipped into the test fluid and after draining microbes will start growing. Interpretation of bacterial and yeast infection depends on individual judgment and genuine differences on reproducibility, but this method is still acceptable for estimating microbial growth in metal working fluids. If there is additional rancidity problem, observations by using dipslide method could be used as a good indicator for adding biocides before problem arise.
Informative info I found on the web.

Spencer in NH said:

I use Hangsterfers S-388 soluble oil in my VMC.

I skim tramp oil, filter particulates and aerate. One thing I have never done is monitor and adjust pH. I do have a pH meter, and can make the measurements. What is the ideal pH? What chemicals are usually used to adjust pH in coolants?

Thanks!

Click to expand...

Hello Spencer,

If you maintain the concentration of your coolant, the pH will generally maintain itself at a constant value. Using Titration kits and pH adjuster to compensate for low pH, is an old school coolant method and is generally not widely seen in the industry anymore. Most Metalworking Fluid Manufactures utilize various additives to give the fluid enough reserve alkalinity to compensate for minimum concentration levels. We want you to be machinists, let us worry about the chemistry. Hangsterfer's is a reputable coolant supplier, and should be able to help you with their various products.

Remember concentration control is the "key" to metalworking fluid success. If maintained properly, your coolant should give you many months, if not years of service life.

Best regards,

Brett Reynolds, CMFS
Sr. Applications Engineer
Customer Service
801-722-4095
Blaser Swisslube Inc.

Just watch the Haas youtube videos. Its the ph of your water. You need tap for the first batch, so it can adhere to the "hard" minerals, after that you use deionized to top off, no "hard" stuff. Chips in your tank are the worst for introducing bacteria, dont let chips in or scoop them out daily. Once a batch is skunked, its dead, theres no reanimating it. Dump it. Why cost yourself in tool life, collet wear, etc.. The coolant guys always push "rejuvenators" of some sort, they are a good aid for aeration and skimming tramp, but thats it. Invest in filters or whatever keeps crap out of the tank, not bacteria cides. Fyi, hydrogen peroxide will neutralize high acidity. Just start googling outside the cnc, get into the chemistry and dynamics involved.
P.s. Chilled tanks are Awesome!