Refractometers

May 30, 2009 12 Replies

Awl --



Apropos of the recent threads on coolant, what's a typical/decent refractometer to buy? Not to buy? $$?



In some threads a while back, some mentioned difficulty using them with dirty coolant (tramp oil) or maybe even old coolant.



Are the mfr's of a given coolant fluent in what concentrations are useful for particular kinds of tasks?



Suppose you are 20% too dilute, and then 20% too concentrated. What diff's would you see in machining "efficiency" (speeds/feeds), tool life, cut finish, etc?



Has anyone ever milled with plain water? Rust issues aside, of course. Many cut ops DO use water -- highspeed alum saws, for one (at least a while back). And some grinding. Water is perty neat in grinding stainless on sanding belts, greatly increased the removal rate in some 1/8 rod that I had to grind to a semi-accurate size -- about .005 in a 1" length.


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The cleaner your coolant the sharper or crisper the line is, so keeping the coolant reasonably clean helps in getting a proper reading.

My Blasers rep is.

Best, Steve

I got a refractometer off of ebay. About $50

They are also used for testing the concentration of soda pop at the machines in the fast food shops, for many cooking and brewing operations... So, they are not too uncommon.

When you look through it, you will see a line, Where the line crosses the scale is the reading. How "fuzzy" the line is tells you how pure or contaminated your mix is. A nice crisp line indicates a clean mixture, as the tramp oil builds up, the line will get fuzzy.

There are lots of tricks and tips about keeping track of it...

With all coolants I use the "Snot Test". Keep increasing the percentage until it feel like snot between your thumb and forefinger. Since you are new to machining let me help you out with this. First inhale something up your nose that will illicit a mucus discharge from your sinus. That will provide you with a comparison calibration gauge. Next dip your right forefinger and thumb into your coolant mix, then wipe your nose with the left forefinger and thumb. (you can switch hands if you wish). Now rub the snot with one hand and rub the coolant with the other hand. When the coolant mix feels as slippery as the snot you are done. That's the way everyone that really knows what they are doing does it.

Does color make a difference? Is green or yellow snot slipperier than clear?

Hoping for some clarification on this.

TIA

Best, Steve

Bill:

I thought that was the way to tell which unmarked oil container had the way oil in it, eh? LOL

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Thats the problem with you beginners, always trying to change the currently accepted paradigm. Well if the man has no snot the man has no snot, improvise, adapt, overcome. Since the best water soluble is almost as good as the worst cutting oil, find some real cheap plain wrap blue strip destinkered sulphur oil. Pry open your wallet, kill the bugs that fly out and buy some "reference oil".

Usually green or yellow indicates an infection. No point in giving yourself an infection just to mix water soluble coolant. I would say clear allergy type snot is the standard and most readily available. Especially in shops that have vaporized water soluble coolant condensing right at nose level. See it's a closed loop system.

All the Fadal's I've ever used have a real tramp oil problem.

Our 6 Haas's have almost no tramp oil in the coolant which is Blasocut.

Jon Banquer San Diego, CA

Same machines you say the Automatic oiler gauges ALWAYS read zero?

Jon Banquer, the guy who discovered the cure for tramp oils......starve your machines of oil.....LOL.

No wonder your tools bang out of the spindle and randomly shoot through the carrousel into the work area.

-- Tom

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Don't get a 0-32% one. 0-10 is what you want. I need to multiply the Brix reading I get on the refractometer by 2 for the Valcool and by 3 for the Cimcool I use. A 0 to 5 would be evern better, never seen one of those.

Thank You, Randy

Remove 333 from email address to reply.

Valcool use to be okay but they changed the formula and didn't tell anyone. The new stuff started rusting machines and tooling, made tool holders stick in the spindle, foamed, etc.

Blasocut is easily a much better coolant and has none of the problems Valcool does.

Jon Banquer San Diego, CA

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