Coolant Management long term

[1ctoolfool]

What kinds of materials or maintenance is required to maintain 50 gallons of coolant over long periods?

What additives or "pellets" are worth the money?

I use kool mist which I love but after a few months I get the floaty oily scum on the surface and also these snot-like deposits that clog the inlet screen. It also seems like i am constantly having to add water and adjust the concentration, is this normal evaporation?

Anyone have experience with additives?
Also would an aerator or circulator pump help?

What about an external tank to periodically cycle and filter the tank coolant?

Any help is appreciated.
Access to the minimill sump is pretty cramped so it is a real hassle to fix any coolant problem when it happens. The roll-out style was much easier to maintain.

[Geof]

Depending on the humidity in your shop and your type of use you may lose easily a couple of gallons a week to evaporation.

For the oil film and scum I have a vacuum extractor that I use to periodically skim the surface after the machine has not been used for a few days.

When the coolant sits for a long time in warm weather with a film of oil it gets a bit rank. It might be possible to prevent this with an aerator but then the oil film would never float to the surface to be skimmed off so I don't use one.

I use Shell Dromus B and if it does get a bit rank I add a few ounces of Creolin and run the coolant pump for a while to mix it in and aerate the mix. Creolin is a coal tar disinfectant that you should be able to get from an agriculture supply place. It has an irritating smell but my machines all have
mist extractors.

I have though about the external tank idea; two of them so one can be left for a while to let the oil separate, then empty the machine into the other and refill the machine with the cleaned coolant and then let the other one settle. I can't see how it could be done effectively with one tank because it takes quite a while for the oil to separate.

One idea I had but never put into practice was to get a cream separator used in processing milk and run the coolant through on a continuous basis. It would be necessary to pump the coolant through a filter first to remove fine metal particles so the separator did not fill with sediment. Maybe someday I will find the time to try this.

[little bubba]

Coolant should need no additives, playing amateur chemist will do nothing but get you in a big stinky mess in the long run. Think of a fish tank, its really no different, you need a nice bacterial balance where all the different bacteria are all eating each others crap. If you are adding biocides (bleach, pinesol, expensive additives that the coolant manufacturer sells you) then you are killing off some of the bacteria, the ones that are left will in short order rapidly intelligently redesign themselves, and start treating the poisons as food. This will create an even nastier bacterial imbalance, and even more nasty stink. You may mask it for a short time, but it will return with a vengance.

Simple rules for good coolant smell. If it has biocides in it,its garbage, don't use it. If you can order coolant, toilet paper and floor wax on the same PO, its garbage. If the manufacturer will sell you anti stink products, its garbage, and the manufacturer knows it.

Maintainance, very simple. Do not spit tobacco, or saliva in the coolant, do not pee in it. Keep food out of it. No soaps inside the machine, EVER!!! (newly mixed coolant in a spray bottle will clean anything inside the machine you need cleaned). Skim regularly, tramp oils and oils off of bar stock will biodegrade. Decant occasionally, this is draining the sump, putting it in a barrel, and letting it sit for a few days. This will allow most of the beat in oils to rise, and all the little particles floating around to sink. Suck off the top scum with a wet dry vac, and put all but the bottom few inches back into service. While the sump is empty, suck all the crap out of the bottom of the tank.

If you are going to let it sit for more than a couple of days, airate it, or if you have dead spots in your sump, you may need to add a pump of some sort.

You may love your coolant, but it can't be that great if you are having problems with it, identify the problems and fix them, or get rid of it.

Also, adjusting concentrations is normal, its called evaporation. The higher the revs and the bigger the tool, the worse it gets. I ran one lathe job in cast iron, that we had to add back 7 gallons of water back into the sump an hour. The chip conveyor looked like a chimney.

[Geof]

Originally Posted by little bubba Coolant should need no additives, playing amateur chemist will do nothing but get you in a big stinky mess in the long run.....

Okay, I stand corrected, I guess a few decades of experience will have to be thrown out the window.

[jkford96]

hello there I have been working on coolant issues for quite some time now the quick of it!!"buy Nalco products" excellant life in the machine.If you are not machining A356 aluminum casting ,or 6061 I recomend the synthetic product line.If you are machining these materials ,go with there semisynthetic line.This one works excellant with thru spindle applications no foam,and lasts in the machine at least 1 year with proper make up(adding to the machine what has evaporated on a daily or weekly interval)

[little bubba]

Originally Posted by Geof Okay, I stand corrected, I guess a few decades of experience will have to be thrown out the window.

You are adding stuff because your sump got "a bit rank". What I am saying, is instead of throwing chemicals into your sump, that you have to pay for in addition to the coolant you already bought, is to figure out why you are getting rank in the first place. Does your coolant suck? do have a tobacco spitter? Sunflower seed spitter? Maintainance issues? Dead areas in the tank?

If you want to spend the extra money, go for it. All I'm saying is that it is very easy to have a sump that never ever stinks and never needs additives. Going on 3 years without a stinky sump issue, and no changeouts (up to a 120 gallon sump). Well, there was one stink issue that cropped up 3 days after a well meaning employee scrubbed the inside of a machine with simple green.

[WILLwork4money]

Well, there was one stink issue that cropped up 3 days after a well meaning employee scrubbed the inside of a machine with simple green.

If it were only that "SIMPLE" and, LittleBubba, I agree with the rest of your post, basic maintenance of coolant is just like "Safety", IT IS ALL ABOUT "COMMON SENSE" [[[[ mind you that some folks have to be tought COMMON SENSE TOO little bubba ]]]]

[1ctoolfool]

I appreciate the help.
I machine 6061-T6 and almost nothing else.
There is no bad smell, just the snotty deposits and the top scum. The snot clogs the inlet screen. The coolant does tarnish the aluminum light brown sometimes and I don't know if this is a concentration issue.

Whats a cheap way to keep track of concentration? Is Kool Mist a synthetic?

Enco shows a general purpose refractometer and then one for low concentrations and synthetics. both on sale for $69.

thanks,
Joe V.

[Geof]

Little Bubba you should read things completely. Here is what I wrote:

"When the coolant sits for a long time in warm weather with a film of oil it gets a bit rank. It might be possible to prevent this with an aerator but then the oil film would never float to the surface to be skimmed off so I don't use one.

I use Shell Dromus B and if it does get a bit rank I add a few ounces of Creolin and run the coolant pump for a while to mix it in and aerate the mix. Creolin is a coal tar disinfectant that you should be able to get from an agriculture supply place."

I know the reason it gets rank and I know different cures, I described what I do, I don't play at being an amateur anything.

Incidentally if you are concerned about money you should check the price of Dromus B.

[HuFlungDung]

Growing bullrushes in one end of the coolant tank might work, but you've got to keep the muskrats out