Can soluble cutting oil damage equipment?

G'day all.

I am not sure if this is the right sub-topic (Maybe 'Beginner's Questions' would be more appropriate).

I was milling a slot in a piece of mild steel and my usual spray can of INOX expired. I had a 4L can of Castrol Clearedge® EP 690 soluble cutting fluid handy (used for making patching my black powder muzzle-loader).

Anyway, what the heck. I mixed a 5% solution into a bottle and squirted onto the job as milling progressed. A very nice (beautiful) finish resulted but I am worried about the milky residue that flooded the 'T' slots etc. (5% mix from Castrol website but 'properties' do not include a {rustability?} figure)

I spent another hour carefully sopping up the residue and removing all the swarf, re-oiling etc but some of the mixture could have escaped under the slides.

It is the water content of the mix that concerns me.

Now I realise that this stuff has been used for ages, and so it can't be too feral, but I only use the mill a couple of times a month so this is maybe different to daily industrial use. Can it cause any damage to the slides etc. if not removed?

Any constructive advice would be welcome.

Regards from the land of the kangaroo

* Danny M *

When it is used daily the constant movement helps a lot. If left for periods the problem is not rusting as such but a biological change which at best stains the slides and table particularly where it is trapped out of sight. Clean it well and use neat cutting oil or similar.

Hi Danny M2Z

Kwil Is right Bacterial action can be a problem, It will rust steel and get very stinky if left in a sump or tray. If you keep your slides nicely oiled that "tramp" oil can hitch a ride and cover the soluble oil in the sump forming a thin film sitting on top of the water emulsion keeping the air away from the soluble oil, an ideal environment for anaerobic (without air) bacteria to form.... very stinky.

Also If you leave a vice on the table watch out for a nasty stain under it when you remove it.

You may wish to have a look through a second hand machinery website, notice the paint has been removed from around the machine, often right down the front of the machine. No not flying chips they cannot reach many of the areas you will see, just the paint being dissolved away.

In my workshop I only use pumped coolant on a large old vertical mill, milling generates a lot of heat and cutters are not cheap coolant makes them last a lot longer, it has a sump in the cast iron base and yes if I have not used it for a while the sump can become a bit of a science experiment. My lathe does have coolant but I prefer to just dab it on when needed. The sump is empty.

Not wishing to be negative but a few people have an allergic reaction to oil and or cutting oil, they can cause dermatitis or other maladies, most people are OK I have no problems, but best keep your hands clean, just in case

Regards
John

Soluble oil certainly spoiled the appearance of bed of my (then) new Myford ML7 before I realised what was happening. The bed wiper felt left some nasty pock marks which continued to annoy me until I disposed of the lathe quite recently. On my new lathe, I only use neat cutting oil (eg Warco Neatcut) but I dilute it 50:50 with paraffin.

Andrew M

I have suds in tanks on both lathes, all three mills and the cylindrical grinder and I've never had a problem with smells, even though the suds may stay in the tanks for many months or even years. Suds can stain the machine surfaces, but I don't have problems with rust, provided I keep the suds at the correct strength.

Neat cutting oils are better lubricants, but much worse than suds for cooling, which one is used depends upon which function you're trying to achieve.

Regards,

Andrew

Danny,

I believe you are quite right to have some concerns. You obviously realise that the main problem with this product is that the oil never ACTUALLY combines with the water , but rather it lies in suspension, and therein is the nub of the conundrum . I also have experienced staining on the slideways on my then newly factory reconditioned Myford. The stains were quickly removed by stoning and the coolant system changed to oil , a decision I have never regreted . I do however continue to use soluable oil on my Kennedy power hacksaw where it is perfectly suitable , principaly because it is totally free draining and is regulalry maintained. Please also be aware that use of soluable oil also brings with it some very real risks associated with Legionellea , particulalry where intermittant usage is envisaged and as briefly refered to in my post of 21/01/2013 under the thread of "Cheap coolant system for a mini-mill ".

Trevor.

Hi Danny,

I scored some soluble oil from work a few years back and after some investigation I found it was just a general purpose cutting fluid .
I use it raw applied with a small brush from a tin can and have had no problems so far , I have used it on the lathe , mill and drill with no problems .

Using Inox must be expensive and being a lubricant versus a cutting fluid I would have though to be counter productive ?

Maybe you could do a test by cleaning up a piece of scrap steel and painting one end with the oil mixed with water and the other end as raw fluid then chuck it out under the carport or something similar and see what happens ?

Ian

I feel I should add a few lines on the subject of coolant/lubricants for machining based on my own work on the chemistry of these.

Not all maching fluids are alike. There are a multitude of formulations out there. Of course some are only available as 200 litre drums and so rarely accessible to the small user.

Firstly neat oils, these have the much longer history and are well understood for their designed purposes. They are the only type to perform well on grinding machines. Surface grinders are very sensitive to the type used.

Secondly so-called suds,these are not actually soluble oils, but often an oil-in-water emulsion, sometimes water-in-oil. Many more formulations exist especially over the last 10 years or so as chemists look at ways of overcoming the deterioration of mixed fluid in the tank. Other problems associated with these fluids are, as mentioned in earlier posts, staining of metal surfaces and most drastic of all, health problems which develop as the fluid ages.

Those health problems can be severe, in one large Midlands plant, now closed, a high proportion of the workforce developed lung problems which lead to the intervention of HSE and was attributed to poor fluid maintenance. There is guidance available **LINK**. and also **LINK** which points to specifics.

There are recently available fluids supplied as concentrates for mixing with water which have shown experimentally and in small and mid-scale practice to be less prone to deterioration.

As this is a topic in which I have a special interest may I ask contributors to be more specific when referring to the fluids they use and the problems which they experience.

Thank you

JerryNotts

I don't think I have seen an article in MEW on coolants/cutting fluids. Surely a short article is required?

JA

G'day Ian et al.

The Castrol website cautions:

'Dilutions
CASTROL CLEAREDGE® EP 690 is designed for use at concentration of 4-8% depending on degree of severity of the operation. Do not run below 3.5% or above 10%.

(I generally use it at 10% to make 'Moose Milk', a traditional black powder cleaning solution. That's why I had it handy).

Generally, I machine aluminium using paraffin, but I found that Inox works quite well to resist the formation of BUE. When machining steel, I had nothing else available and it seemed to do the trick.

I pulled the mill apart today. It did have some residue under the slides but no ill effects so far. I cleaned it out and lubed them with some 3-in-1spray white lithium grease. It is not easy to find much else here in the bush.

Regards from the land of the kangaroo

* Danny M *

Interesting, the manual for my cylindrical grinder specifically recommends a water/oil mixture, at 40:1 dilution?

Andrew

I guess adding Domestos would be a bad idea because of the chlorine content. How about a UV light in the pipe? Another traditional bactericide is copper - dunk you copper turnings in the tank?

Does slathering the underside of the vice with grease seal out the fluid or does the fluid disolve it too readily.

Domestos is a no no unless you like rust... even stainless will succumb if you soak it in it.

I have heard of using an aquarium pump to oxygenate the water emulsion in the sump, the anaerobes don't like oxygen. you have to run the pump as well to flush the pipes.

Regards

John

I have been using pumped NEATCUT oil for several months now for lathe and milling machine because I have an uninsulated workshop and the theory was that it would anoint everything and stop my kit rusting. It sure does that very well.

In addition, there is no risk of finding the coolant tank frozen solid after a cold night, no risk of stenchy bacterial reactions and it has virtually no smell.

Disadvantages are: I need to wait overnight before removing swarf from machines to give it chance to drain. I wear BODYGUARD nitrile gloves at all times as I don't feel it a good idea to be in regular contact with the stuff. and finally - its messy - no two ways about it. However, I prefer a bit of messiness to rusting machines and tooling.

Andrew M - isn't that cocktail of paraffin and oil a bit smelly? Maybe if you are only brushing it on its not so bad.

As for mystics causing staining :

Take a brand new Jones & Shipman (say) surface grinder and use it daily (during the working week of course) with mystic for two years. Then detach the magnetic chuck for the first time since new from the bed. Staining? Thick rust more like!!!

The best mystic I ever used on a grinder was supplied by Cincinnati Milacron. When mixed it looked just like water with a slight bluish tinge - really good stuff. The worse was used in a large, little used universal grinder in a dark corner of the factory. This stuff was yellow, milky and stunk like a mixture of rancid cheese, stale sweat and mildew - a bit like a politician I 'spose!

Rik

Edited By Rik Shaw on 16/10/2013 18:03:40

Perhaps I should have emphasised the message contained in the links I referred to earlier in relation to water borne cutting fluids.

If it smells of anything other than a mild oily aroma the fluid has 'gone off' and should be discarded, the reservoir thoroughly cleaned, not just a water flush, but employing the process recommended by the manufacturer.

It should be noted that as far as I know no machine tool manufacturer has ever supplied a fluid of his own manufacture. The chemical industry is plagued by 're-labelling' .

As to the ideas surrounding the addition of biocides, such as bleach, to coolant I think you will find that is deprecated by the manufacturers and I would not be surprised that any suggestion of a claim of health due to fluid which has been dosed with anything other than the manufacturers approved additives would be rejected.

Fluid manufacturers have always employed formulators and R&D staff to help develop their products: even with the best of resources companies across the World have found this a challenge, and progress is ongoing.

JerryNotts

Many years ago I knew a guy who had worked at Porton Down - not on germ warfare, but on the bacteria living on the oil/water interface in big storage tanks. Apparently the gas they generated caused no end of issues.

Neil

Well it happens sometime on some materials where the rust comes off from the equipment after using a soluble cutting oil. This happens when the equipment is not polished earlier or have been not used for long....