Two weeks ago me and one of my cronies had the opportunity to check out a quick presentation by one of the Blaser reps. First we have been using Blaser for a year and a half with no stink problems, except for once and that was a low concentration problem. Anyway, I think I learned a lot and am now quite excited about our coolant, not as excited as this guy got, but close, (we talked to him(his name is Uli by the way, really cool guy) for about 3 hours after the seminar about coolant).
I'll try and explain some of the things I learned, stink related and otherwise.
First is what coolant does, it cools and lubricates, I never knew how it lubricated but apparently it has a lot to do with chlorine, chlorinated parafins if I remember correctly, they actually react with the metal your cutting and at the hot part of the chip creat a lubricant of aluminum chloride or titanium cloride or whatever your cutting. This is almost the same as a TiN or TiAlNn coating, just more fragile and thinner, apparently sulfer does the same thing in a straight cutting oil, just it doesn't do it until you reach a higher temperature.
Now the stink factor, most coolant use a biocide to kill all bacteria, this works for a bit until the bacteria become used to the biocide (rapid evolution) and actually feed on it, hence major stinkage. Blaser (my favorite coolant, no affiliation, just a satisfied customer) uses no biocide and lets nature take its course, kind of like a fish tank. Now the things that can make stinky coolant are way lube, impurities (spitting in the coolant, coffee, tobacco, etc) sulfur based cutting oils (tapping fluid). Also mud on the bottom of the tank, this is basically minute particles of metal that creat a 'dead zone' for anaroebic bacteria to live in(stinky).
Other cool things I learned, synthetics are basically the same as solubles without the mineral oil, the only problem with that is the chlorides and other additives can now become airborne with evaporation without the emulsified oils to hold them in, hence shorter coolant life because the stuff you paid for is now floating away in the air instead of in your sump.
I also learned that coolant maintainance is fairly important. Apparantly we abused our cooant, not skimming, never cleaning the sump, mixing incorrectly etc. Mixing improperly can cause an inverse imulsion, similar to a mayonaise, in which the oil holds the water, instead of the water holding the oil, apparently this can make a difference in heat distribution properties which can translate to bad tool life.
On the skimming thing. Coolant is made to promote metal to metal contact so that the chlorides can do their thing and everything happens as it susposed to, however if you don't skim, your waylube gets into your coolant and this type of oil does not promote metal to metal contact (thats why we use way lube, right?) This screws everything all up, now if you don't skim often enough some of your waylube ends up emulsified into your coolant and then things are perpetually screwed up. Also some waylubes have things in them that those stinky bacteria like to eat, hence, stink, also it creates a barrier to the air in your sump, hence anaroebic bacteria, hence stink. I guess most coolant companies make a waylube that is specifically designed to seperate from their coolant for easy skimming, we just bought a bucket of Blaser waylube and it was only $2 more than the chevron purple stuff we normally use.
Another thing learned is about concentrations, if your under concentrated you run the risk of stink. We've always used a refractometer and I always thought that I was just tired when I couldn't get a nice crisp line. Turns out the fuzzy line is mixed in oils that don't belong there. so if the top of the 'fuzzy' is at 12 and the bottom at 10 I would average it out to be 11. WRONG. You need to take the range of fuzzy, 2 on the above example, then invert it downwards, which gives an actual reading of 8, so fuzzy from 10-12 means your actually at 8% and you have a whole lot of oils mixed in.
As for coolant maintainance, skim at least weekly, this also includes the milkshakey stuff between the tramp oils and the 'pretty' coolant, this is the coolant that the tramp oils have been severly beaten into (the fuzzy reading). Also about every 4-8 weeks decant your machine, this involves sucking all the coolant out on a Friday afternoon, sticking it in a drum, and letting it sit. On Monday morning suck the crap off of the top with a wet dry vac and then drain off the rest back into the machine, except the very bottom. This is where all the suspended particles will settle. You may make big chips , but you are also making little chips, and the worst place for these tiny tiny chips to be is being blown into your cut at high pressure, it can be abrasive, therefore lower tool life.
I've gained a whole new perspective on coolant, and I'm very happy with the brand we are using, and the support they will give you(they won't sell through a janitorial warehouse). Its not off the wall expensive, and you never have to throw it away, just maintain it, or not as I've proven through 16 months of total abuse on a 120 gallon sump.  |
06-21-2005, 12:57 PM
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