Coolant Help!

[stang623]

I have recently acquired a Horizontal CNC that was absolutely filthy. After a good bath in the parking lot before moving it in and another bath while replacing the z axis ball screw it is in much better shape. The problem is the coolant, we added new coolant but what was in there was filthy and killed the new coolant quickly, that and the fact that we have been saving for a new vise tower so it hasnt run much at all except for a couple of test cuts.

Anyways I've come to the conclusion that the coolant tanks need a very good wash down with some kind of disinfectant. Here are my options as I will be doing it this weekend. I have got to get it going before the new year comes so that when we get back to work it is ready to work.

I have got two options on what to use to kill the bacteria and filth in the tank. Either bleach or ammonia. I haven't seen anyone on this board mention ammonia but the mazak rep at PRI told me that they use ammonia to "destink" a machine. I will than probably give it an intermediate flush with light coolant and then a final fill with coolant. The tanks hold about 80-90 gallons of coolant so I have my work cut out for me.

Which one would you guys recommend and what dilution do you think?

Thanks,
Anthony

[shay z]

I recommend to contact the cooling fluid supplier and ask hom to provide the right disinfectant. at least in israel most suppliers provide it for free.

it is not enogh to pour it to the old coolant. you must run the system for few hors to clean all the pipes.

[stang623]

I plan to empty the coolant currently in the tanks and then add a water/bleach or water/ammonia mix to the tanks and pump it around for 1-2 hours making sure to rinse everything off that has come in contact with the coolant.

I don't have the time to wait for some dissinfectant from another supplier right now, gotta get it done this weekend so I only have what is available locally.

Thanks,
Anthony

[mc-motorsports]

I vote for bleach, but I was told the only reason you can't use it in shops is because OSHA won't allow it. Other than that, bleach is the best disinfectant I know of, but make sure you run it out of your tanks, bleach can cause rust, salt water based.

[OrionBlade2003]

Bleach and ammonia are both bad when you mix them with hydrocarbons.

Bad bad bad bad.

Also bad if you mix them together.

ZOMG.

*BS in biology/minor in chem + extensive lab experience*

Use boric acid.

Seriously, just mix up a super saturated solution of borax (20 mule team Borax laundry booster) it comes in a greenish box with an off white label/red banner on the front.

I use it all the time when forge welding, as a flux. It's fairly inert in and of itself, and won't rust metal to hell, but bacteria HATE it. Wonderful antifungal, and I tend to think that's what you've got (fungi love oil - bacteria not so much)

Long story short, you can use vinegar and borax together, or just the borax in water, and it makes a wonderful disinfectant. It's actually pretty good in a pressure washer as well, for taking the mold off deck boards and keeping them from rotting. Think poor man's pressure treating.

AND YOU CAN EAT IT!!!

kinda. The D50 for borax is slightly higher than that for table salt. In other words you'd have to eat so much (about a pound) before you croaked that you'd have other things go wrong before you actually died from the borax/boric acid itself. I.e. cotton mouth anyone?

Also, it'll exfoliate your skin and leave your hands baby soft.

My reccomendation would be to run water through your coffee pot, and put a cup or so of borax in a filter. Run the pot like you're making coffee, and the hot water will dissolve the borax and come as close to a saturated solution as you're likely to get. Also, the hot water will help disinfect things in and of itself.

Rinse well, and to neutralize, do the same thing, but with a cup of baking soda. Run one pot of the baking soda, and pour it into a spray bottle to spritz down anything you can reach, and the rest you should just pour into your coolant tank and slosh around. Dump it out, rinse, and refill with your coolant.

Boric acid and baking soda will likely not react with an oil or emulsified oil, while chlorine can do crazy things to anything with oil in it. Basically it'll make it rancid, just like the fungus has. A tiny bit of boric acid in with your coolant is a nice pickle that'll keep it from growing goopy stuff when disused for long periods, and will actually help maintain the emulsification longer!

Happy trails,
Rion

http://www.desertusa.com/mag05/jul/borax.html (Yep, Ol' Ronnie pitched it back in the '50's - scroll to the last paragraph!)

[OrionBlade2003]

Just had a thought - if you want to get real fancy, you can toss in some fenugreek. It's a leafy herb, typically found in indian food - go to an indian/south asian market (think pakistan, india, thailand, etc.) or bazaar. It looks kind of like sage, I think, or a bit like basil. Just dried up leaves. Toss in a few leaves, or a spoonful or two of ground leaves, and you'll have an amazing (hand-of-god miraculous) antimicrobial compound. I've seen the results of a test where supermarket strawberries were spritzed with fenugreek "tea". The untreated berries went bad within five days, the treated berries were edible and fresh after nearly five WEEKS.

This stuff kills EVERYTHING, and it tastes kinda good, actually.

And don't worry, I'm not a tree-hugger, I just reallllly like not using toxic stuff when possible. Especially when it smells good ;-)

One warning, tho - it does get a bit slimy if you have too much of it, especially with the borax it'll feel really soapy, so try not to get it on your hands directly or it'll feel icky for quite a while. Think cotton candy in terms of handling practices.

Rion

[mc-motorsports]

Can I ask what happens when you mix bleach with hydrocarbons? And I know they refer to "coolant" as "oil", and this might sound dumb, but forgive me, I don't have my BS is biology or chemistry, but I was under the impression that "coolant" isn't a hydrocarbon in the same respect as gasoline or kerosine, just the simple fact that you mix it with water made me think otherwise.

[OrionBlade2003]

Nucleophile. Chem term, explanation coming...

hydrocarbons, by definition are hydrogen and carbon, often with other junk.

You, yourself, are nothing but a big pile of hydrocarbons.

Pshh. Freaking hydrocarbons.

Oil/gasoline/kerosene are all hydrocarbons. Most coolants I know of (or knew of when I took my CNC courses about 3 years ago and did a stint with my school's formula team) are actually water emulsified oils.

emulsified just means it's kind of a solution, but the stuff that's "dissolved" isn't really "dissolved" its just evenly dispersed. Sugar dissolves, because each molecule of sugar gets surrounded by molecules of water, and these "spheres of hydration" float around in the otherwise pure water. It's a solution.

Emulsified oils are like vinagrette salad dressing, tomato soup, double mocha frappuccinos, and mayonnaise.

yes, mayonnaise is like machine coolant.

ZOMGWTF don't drink that!!!

:-p

Basically it's just some gunk in water that makes an oil float around as a bazillion tiny droplets throughout the water, instead of a film on top. The oil coats the tool/work/machine surface, and the water acts as a heat sink and flushing medium.

If you add chlorine to a hydrocarbon, all sorts of things happen, but if you want a good demonstration of how bad it can get, just take some brake fluid and a pool chlorinator tablets (the higher percentage of flouro- or chloro- compound the better. It'll read something like Sodium (something)hypochlorite.........57% so just look for the chlor or flour, and a big number percentage)

Get a long stick, and pour the brake fluid onto the tablet using the long stick, far away from flammables.

You now have rocket fuel.

In aqueous solutions like disinfectant and coolant mixing, you'll get weird oxidative changes to the oil, and the chlorine can degrade seals, bushings, anything rubber. The bigger problem is you're not dealing with chlorine gas or hydrogen chloride (hydrochloric acid). You're actually dealing with an alkali metal, chlorine, and a ton of oxygen. You might as well toss your mill into the ocean hooked up to one terminal of a car battery.

That's a bit extreme, but chlorine itself has the nasty habit of being a catalytic oxidizer. Instead of sticking to ONE hydrogen atom on ONE oil molecule, it'll interact, snip the molecule in half, and then move on to do the same to a thousand more molecules. And that's just one chlorine atom.

Bleach is, however, very handy for turning the inner thou or so of a latex garment into neoprene, which makes it easier to put on. If you've got a pair of hard-to-put-on gloves or a BDSM hood or something, and it's latex, then turn it inside out and dunk it in Clorox for a few minutes. The neoprene is much more forgiving of skin contact.

This is actually not a bad thing for gaskets on your machine, and in small quantities it's not really going to be noticeable, but when there are other non toxic and safer-on-your-stuff alternatives, try those first.

Quite possibly the very very best option would be hydrogen peroxide, but in the presence of oil, it'll foam up and oxidize the snot out of all sorts of things, so it's probbably more of a mess than anyone wants to deal with. It would produce some not-so-nice by products, but they're all oxides, and not halogens like the clorox would do.

Ammonia's just nasty stuff no matter what you do to it. My rule of thumb is, if you can't drink it without getting sick, and it's used as rocket fuel, then don't touch it without protective gear. In a lab setting, if you didn't walk in with it, then you don't know, so don't touch it without protective gear. Just a general lab safety rule of thumb.

Hope that answers your question. I kind of dozed for a bit before the little notification came in that you replied, so if I wandered a bit, blame my new puppy.

Or not, he's cute, and asleep on my feet. Strange how a 6 month old pup can suddenly and thoroughly integrate himself into my routine like he's been here the whole time. Some dickwad decided they needed bait for their dog fighting operation, and he was it. Now he's mine, thanks to the sheriff's office. Anyone need a license plate? I know a couple guys that might be making them professionally soon!

;-)

So yeah, I'd rather little Maxwell here lick up some borax and fenugreek than clorox and ammonia. For swab-application, however, I wouldn't hesitate to use straight bleach and some techspray or kimwipe swabs - the artificial chamois stuff, not the cotton ones, since they leave lint.

Later,
Rion

[mc-motorsports]

Wow! That pretty much answers my question! Thank you,
MC

[OrionBlade2003]

Hope I cleared things up.

If you think about it, that's funny. Emulsions... clear things up.

*snicker snicker*

Biology joke.

Anyhow, MERRY CHRISTMAS (and such) and goodnight!

Rion

[ImanCarrot]

if you didn't walk in with it, then you don't know, so don't touch it without protective gear

And that is one of the most good tips I've heard in a long time. It should be stuck up in every lab in big red letters. Nice one.

I use hydrofluoric and hydrochloric acids. If the mohlar solution isn't perfect then it doesn't work. I will not use anyone elses mix. I always mix my own. Same as when I'm mixing Sodium Hydroxide.

Oh (back on topic)- I used bleach in my coolant sump when it was stinky- I ran it through for a day and it killed the problem. I then replaced the bleached coolant with new stuff so that it wouldn't rust things.

Once you get it all sweet then use a little aerator (like what you get in fish tanks) to pump air into the sump. Bacteria dun like it and they can't breed in aerated coolant (something to do with anerobic thingies).

[Edit]Oh, I use a medical test kit thingy to check my coolant for bacteria like yeast and stuff, the test slides show up a different colour and shape for each type of contamination, a bit over the top granted cos it aint gonna kill you, but my main critera for sorting the sump is "if it smells like you've left your washing in the washing machine for three days, then it's time to do something about it" [/Edit]

[plastibob]

I used a sump cleaner from JTMproducts and it worked great. The machine I brought was a little nasty but this took care of it.