Cutting Oil Fumes

Loadsa steel to remove machining a blank arbour to make an adaptor for a non-standard chuck. Cutting happily away with an indexable cutter amidst great clouds of fumes from hot cutting oil in a not-too-well-ventilated workshop. Now I love the smell of hot cutting oil, second only to that wonderful combination of hot oil, coal smoke and steam from a loco, but common sense says it's probably bad to be breathing it.

Thoughts or advice please - a couple of centuries of machine tools must have come up with some evidence on this.

Cheered up by nice new Tshirt from No.1 son for my 72nd Birthday.

Thoughts: not good to be inhaling any smoke

Advice: improve ventilation? Cut dry? Flood cooling?

The T- shirt: I LIKE it.🙂

Ive been thinking about the same problem myself, although I where a p3 gas and fume respirator as a temporary stop gap.

Long term I am considering building an extraction hood, perhaps using a bathroom condensation fan and pipe out the window or perhaps small chimney. Not sure what the neighbours would think with burnt engine oil smoke blowing about!

An extractor fan as mentioned is a good idea. I have a reclaimed from scrap bath extractor fan and ducting to a window in the downstairs workshop, and it works well to keep cutting oil smoke or solvent fumes at bay.

Great T shirt! where did No 1 son find that?

At my age I don't worry about it.

With traffic fumes etc!

I bought a decent bathroom extractor and use that when using a lot of cutting oil, works a treat!

Jim

Inhaling cutting oil fumes is not a good idea, an extractor fan as suggested by others is a good idea. I usually cut dry when using carbide tipped tools, except may be for the finishing cut or when cutting difficult materials.

Thor

Life expectancy of retired professional engineers by discipline used to show that chemical engineers had the earliest deaths presumably due (in the old days) to the use of the nose for chemical identification.

Colin

As an apprentice at Weybridge, we used to pass through the heavy machine shop (Undercarridges and engine beams etc) on our way up to the canteen - loved the smell of that thick brown neat oil the food wasn't too bad either!

No need to use cutting oil with carbide tooling in a home workshop setting. If the swarf is coming off blue, it's all good. Too many red sparks flying about mean you could slow the rpm down a bit to preserve tool edge life. I avoid the stinky stuff for all except screwcutting and parting off, both of which I do with HSS. With carbide I would not bother there either.

Dont know of any specific health risk in cutting oil fumes but in an unventilated workshop I would give it a miss on general principle and the above lack of necessity -- and the pong.

As a young toolmaker I spent years operating a "Keller" copy milling machine. The cutting oil used was a mixture of Lard Oil and Paraffin. (lard oil is tallow based)

I survived but given that any fumes or dust are an irritant I try to avoid them.

I recently had a very bad experience with cutting fumes. Having run out of my usual parafin based mix for milling ali I resorted to using what I had to hand, Kerosene (It stopped the cutter from clogging-just about). There was a lot to mill and there was a lot of smoke. After about half an hour I realised that I could no longer concentrate and had a bad headache. I got out the workshp - felt terrible. An hour later was back to normal. Lesson learned, quite scary at the time though.

Just ventilate.

Tony

Depends on how concentrated the fumes are, how long you breath them, and what your personal sensitivity is. Sensitivity is a tricky one because Mr Delicate has no problem because he feels ill quickly and runs away, while Mr Insensitive feels fine and gets Emphysema shortly after retiring.

Health issues are unlikely in a well ventilated home workshop because exposure to fumes is occasional and brief. But anyone regularly breathing in lots of smoke, fumes or exhaust gases should take steps to reduce the risk. Ventilate and extract mainly, maybe a mask.

Smokers should be aware that breathing fumes through a lit cigarette massively multiplies the risks. It's because passing fumes through a flame breaks them down chemically, not necessarily for the better! Before Health and Safety Phosgene poisoning was surprisingly common because sucking the fumes from a common degreaser (Carbon Tetrachloride) through a fag converts it into an exceptionally toxic poison.

Dave

Why use cutting oil,lot less problems with soluble oil, years ago there were where i once worked over a hundred auto lathes going llke mad all day,there was no real objectional smell or much in the way of fumes,as the lubrication was cutting oil and lots of it in full flood and did not get hot ,plus very little if any carbide in those days.Its not a good idea to use cutting oil in small quantities on red hot chips.

With Carbide, run dry, The tip should be quite happy until the chips come off red.

Either that or use flood coolant. Intermittent coolant supply can lead to cracking of the edge.

In general, don't inhale the fumes, and ventilate the shop, ideally with a fan to promote airv movement.

That's my 2 pennorth

Howard

Just reviving this old thread. First real go at using the lathe (at least first time making something for purpose) And was a bit disappoint at the smoke it was creating, seems pretty obvious it would be unwise to be breathing this stuff in, although I did today. I was cutting back 70mm from the end of a bit of 20mm dia bright steel bar to 15mm. I was told to apply a dab of cutting oil to the surface before each cut. It was fair smoking, The cutting could be described a bluish spirals.

I may be should have worn my forced ventilation ffp2 helmet that I use for wood tuning, (not sure if ffp2 is useful against smoke?) Creating ventilation could be a problem (unless I start using it a lot)

However I read this thread with great interest - as I was using a carbide cutter (or at least I think I was, brass coloured diamond shpaed bit), may be I need not have used any cutting oil (or may be just some for the final cut)

So to my question - Is it fairly agreed that not using any cutting oil is OK when using a carbide or tungstan Carbide bit on mild steel ?

and here it is (a new axle for a sack barrow) quite proud of it.

Hi Justin,

As I said in my 2021 post, when using carbide tipped tools I usually don't use any cutting oil for the roughing cuts. I do use oil for a light finishing cut as it seems to improve the surface finish.

Thor

There is soluble cutting oil, based on water, which is primarily for cooling with a little lubrication. And there is neat cutting oil which is primarily for lubrication on high pressure cutting operations with a little coolant. Applyin a dab of either before cutting is a waste of time. All it will do, with cutting oil, is produce smoke.

With carbide lathe tooling I always cut dry, except when parting off. I use soluble oil on the lathe and run flood coolant if I need it, mostly with HSS tooling.

The part shown will be fine as sackbarrow axle, but the finish isn't particularly good. What is the provenance of the steel and the carbide insert? What speeds, feeds and depth of cut were being used?

Andrew

As well as whether tailstock support was used. Guessing it was as it should have been.

Not important, but did you check for taper? It looks like that finishing cut was of too little depth for the cutter?