How to tell "Cutting Oil" from "Lubricating Oil"

I think that the test you want is for sulfur. Some of the newer cutting oils have other ingredients that may or may not be a probleem. For example, I have no idea what triethanolamine is, but DoALL cutting oil contains it. Likewise, hexylene glycol, which is there in tiny amounts.

But it's likely that sulfur is the big one. Also, lard oil leaves gummy residue when it oxidizes. That may be it, too.

But what you're really looking for is an indicator that a material is or is not cutting oil. There's no assurance of this, but most dedicated cutting oils have contained sulfur for decades. The ones that don't are more recent forumulations.

Maybe someone knows how to test for sulfur. There used to be a test that involved a silver compound of some kind.

Good luck.

sulphur will tarnish silver. Dip a clean silver spoon or fork in the oil. If it tarnishes you KNOW it has sulphur. If it doesn't you are still guessing.

You could do a Lassaignes test (look it up) - but for "several tons" it would be worth having an oil analysis done - the spectrometer will tell you the WHOLE story.

I wonder what the chances are that there's a mix of cutting and lubricating oil. And, even if sulfer isn't present, there might be other components not good for the burner, or that might emit toxic fumes. (more toxic than from burning straight lubricating oil...)

Jon

"Ignoramus14057" wrote in message news:W82dnfaKoL9GPh7HnZ2dnUU7-N snipped-for-privacy@giganews.com...

The simple test for sulfur is to heat the oil and see if it tarnishes polished copper. I don't know how to detect other cutting oil additives, that test is for fuel or lubricating oil.

See pages 8 and 9.

Chemistry has moved to more sensitive and accurate testing with instruments, so the simple and accessible methods are in old books. You might find more by searching for the "copper mirror" test with a newer computer than mine.

Another simple test is to burn a small quantity and look for a solid residue of ash from additives. You could compare the result to the residues or lack of them from known samples of hydraulic, motor and cutting oils.

But I can't tell you if the oil is safe or legal to burn.

I'm guessing that the manufacturer of Iggy's oil burner was more concerned about damage to the burners than to pollution, unless it's a new one.

Until the last decade or so, industrial cutting oils usually contained sulfur and, often, they were chlorinated. Neither one sounds healthy for metal burners -- or for your lungs.

Cutting oil recycled in a sump is sure to contain ultrafine metal particles, as well. Filters in those systems have their limits.

Cutting oils might have heavy metals in them which the EPA doesn't want floating around the atmo. Or the chlorinated types might corrode the burners or valving.

I wonder how much it would cost to have a lab test it for composition. You're in the right area for it: industrial. I wonder if oil recyclers have that capacity now.

If the oil contains chlorinated hydrcarbons then phosgene gas being generated in a furnace is a disitinct likelyhood. Since chlorinated hydrocarbons used to be in several pretty common tapping fluids and are still used as degreasers today they might be in that oil. I'll bet an oil analysis isn't very expensive compared to the money you can save burning the stuff and the money it would cost you if your furnace was damaged. Or if you or somebody else breathed in a little phosgene. Are you required to take the oil? How much time do you have to test the oil? Eric

Regulations or not, some oil additives or contaminants may end up making na sty fumes that you may end up breathing. Lab tests for oils are cheap - $28 from this place

I'm sure you could find a place in the Chicago area to do it, and then you'll k now for sure what you have.

Perhaps fine metal particles that would damage the pump and/or nozzles.

Regulations or not, some oil additives or contaminants may end up making nasty fumes that you may end up breathing. Lab tests for oils are cheap - $28 from this place

I'm sure you could find a place in the Chicago area to do it, and then you'll know for sure what you have.

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According to this

they can test only for elements that correspond to fixed slit positions (wavelengths) in the spectrum. The elements of interest in engine oil come from the gears and bearings and aren't all the same as in cutting oil. I would ask them if they know and can test for the additives in cutting fluids, such as halogens.

"On a simple level, flame emission spectroscopy can be observed using just a flame and samples of metal salts. This method of qualitative analysis is called a flame test. For example, sodium salts placed in the flame will glow yellow from sodium ions, while strontium (used in road flares) ions color it red. Copper wire will create a blue colored flame, however in the presence of chloride gives green (molecular contribution by CuCl)."

I learned spectroscopy on an instrument built in the 1930's that projected the spectrum from the sample onto a glass plate negative.

-jsw

Sounds like optical emission spectroscopy where in the old days the machines would be tailored to the type of samples being analysed by placing the photomultiplier tubes on the spectrum lines to detect the elements signature lines spread out by the prism. I worked in that field for a number of years but not at the detailed end , mainly the user interface end but you still pick up how it works and I was shown some of the old gear where you had to take the readings off meters. These days as I understand it they use CCDs and the instrument is more versatile in its analysis range. I'm out of that field now so things may have moved on further but the background science is the same but the means of accessing it improves.

"Each beam of light is then directed to a tiny slit on what is called an aperture plate. The aperture plate is a thick metal device, about

10 inches wide by 18 inches long, and the slits engraved in it are finer than a human hair. The aperture plate allows us to measure the intensity of each beam, using a device known as a photomultiplier tube."

Photomultipliers are light-amplifying vacuum tubes, the ancestors of the microchannel plate.

-jsw

Point taken, but that's just one lab. This place

can test for all sorts of things, including Sulfur in Oil.

Of course, rather than having a bunch of rcm folks speculating, the thing to do would be to call the heater manufacturer and ask them how to tell if the oil is OK for burning in their unit, and what the reasons are for not allowing cutting oil.

And Iggy, why haven't you scrounged a mass spectrometer for under fifty bucks? I wouldn't be at all surprised if they were junked regularly by schools, government labs, etc.

I know how to use electronic, chemical and mechanical test instruments and grab whatever I see for sale, but except for oscilloscopes they are -very- rare. I searched for an RF spectrum analyzer for many years, then after finding one spent a couple more years looking for a tracking generator to use it as a scalar network analyzer.

For some of them you need training and equipment to keep them calibrated and prepare the test samples, too.

I learned this at a part-time laboratory job while in high school.

-jsw

Even weighing things requires care and some training.

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I'm not trivializing the skill it takes to run this sort of test. I'm just pointing out that stuff like this often ends up in the garbage (rather than at an auction house) because either someone is too lazy or the institution doesn't have a mechanism for selling or donating excess equipment, but des troying it is easy.

That you have had a hard time finding the equipment that you're looking for is due, in some part, to the fact that you're not Iggy. He seems to have a real knack for this. After all, we're talking about a ton or so of oil tha t's merely incidental to a scrap metal purchase.

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Further to all of this, I mentioned oil testing services because they are r elatively plentiful and cheap, but easily as plentiful but maybe not as che ap (I don't know, never having used one) are analytical laboratories that h ave the capability of showing you whatever detail you are willing to pay fo r.

I'm not trivializing the skill it takes to run this sort of test. I'm just pointing out that stuff like this often ends up in the garbage (rather than at an auction house) because either someone is too lazy or the institution doesn't have a mechanism for selling or donating excess equipment, but destroying it is easy.

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A town employee who sees interesting things at the dump gives me some. I have a Harbor Freight 61969 miter saw in the repair queue for this spring, in exchange for working on a generator he salvaged for his dad.

Thanks a lot. I tried this method with a polished copper bar. The bar did not tarnish. I decided to take the oil and took three large caged plastic totes with oil and two barrels. I definitely appreciate the help and I enjoyed that old book from 1920.