You wouldn't catch me using motor oil. There is a post further down lubricating a mill. Same applies to a lathe.

John

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Very interesting set of articles about grease there, we always had a list in the workshop for which grease to use on which job and also which greases not to mix with each other.

Classic oils don't have the additives in to keep contaminants suspended in the oil, that's why old car engines were dirty inside and modern engines are clean, however I thought they had most of the other additives in so I'm surprised you found such a difference in operation, I know the slideway oil I've been using is better than the engine oil I was using.

Steve

Clean engine oil is not ideal but if it was highly hazardous would it be on the shelf at the supermarket where children may buy it?

Almost all petrochemicals are carcinogenic (petrol, diesel, engine oil, paraffin, kerosene etc), either from fractions within (like benzene, toluene etc) or the tiny residues like pyrobenzine which are extremely carcinogenic. We sell all manner of these freely in garages and shops.

Don't ever be tempted to reuse used engine oil – it absorbs byproducts of combustion so that the concentration of nasties like benzopyrene build up with time.

One pathway into the body for these petroleum nasties is digestion, where you end up cleaning your hands as you eat. Common cancers caused by ingestion as well as the above also include the nether regions and scrotum. Nice.

Then there is alcohol which is fairly carcinogenic too and causes large numbers of cases of cancer of the mouth, throat, stomach, liver, bladder etc each year. At least we are gradually starting to ban smoking finally….

Yes, my dad used to be an industrial toxicologist and I still have his library.

Daylight is carcinogenic and bananas are radioactive but a bit of common is required.

I have just completed the modification to the gearbox on my WM280 as described by journeyman on his website http://journeymans-workshop.uk/lathemaint.php using the same oil Halfords Gear Oil EP 80W/90 GL-4, before doing this I read up on the oil specifications and found out that the GL rating is very important as GL-4 is safe to use on yellow metal bearings, brass, phosphor bronze, etc but GL-5 will corrode them so be careful which one you use.

The back of the gearbox plate that you have to remove to install the mod was 1/8" thick spongy rust and the residue in the bottom of the gearbox was a gooey mess so stripped the whole assembly down and cleaned it but you have to put a chamfer on the holes the gear change knob shafts pass through as otherwise the sharp edge cuts the sealing o rings tops off.

Resealed it with a flange sealant and all working well now with no leaks.

Thanks to journeyman for the description.

It's worth reading up on the different oil specs as it seems unwise to use an engine oil designed for hot environments in a cold gearbox, remember there's no engine heat to transfer through the casings and engines and gearboxes work under different conditions. Engine oil is slippery but so's hair oil and bath oil but you wouldn't use them in a gearbox – or would you?

I fail to understand why people use engine oil for general lubrication of a lathe when they can buy iso 32 hydraulic oil instead. Personally though I find the best thing for slide ways is slide way oil. Little is needed and it hangs around for some time and doesn't absorbing moisture from the air or gum up like most automotive oils do. In fact I wish I could get the next grade up in small quantaties which is suitable for vertical surfaces. Automotive oils are designed to run hot for long periods. They also have all sorts of additives in them. It's also well know in some circles that if these oils are changed at say twice the recommended interval things might never wear out. They aren't as great as some might think. They did get well ahead of engine etc technology for a while but those days have gone.

Real gearhead lathes generally use hardened and ground gears. It's easy to see when a lathe has these or even by ear. I'm not at all sure what I would use to lubricate typical Chinese use of gears in small lathes and millers but I would like the sludge worn from the gears to settle at the bottom rather than circulate and grind the gears down further. I'm inclined to use grease on the back gears of my boxford and oil on change wheels and gearbox etc. I have been a bit naughty on change wheels I should use ISO 32 but use a GP oil.

I've not looked at Chinese lathe ball/roller bearings but suspect just as when the Koreans were the source of smaller lathes that some wont be hardened. From memory ArcEuro have some pages on changing NVG bearings. I've used molyslip grease on bearings for some time. My lathes have been relatively low speed in terms of what typical greases can handle. Of late because it's available I use a high speed one that ArcEuro sell. Believe it or not it will extend life. It's important to not add too much grease of any sort to bearings of this type.

Plain bearings – Myford etc really do need to use the right lubricant if they are to last. I'd hazard a guess that ISO 32 hydraulic oil meets the spec for these as well – a highly refined mineral oil.

John

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I don't think I would use my cutting oil Neil. It tends to collapse bottles it's left in and go down all on it's own. I just smear some on work at times. I cured the disappearing oil by putting in a sealed jam jar with a test tube strapped to the side. I just take a few gollops out of the bottle and drip it into the test tube. The test tube also serves to hold the brush I use.

The cutting oil came mail order from Morris Lubricants. 5lt which should last me for ever. Good but not as good as the thicker stuff that used to be used on auto's where splash got on peoples overalls and gave the testicle cancer and dermatitis elsewhere – there is a message there about using oils intended for other purposes. The stink of some automotive stuff is enough to put me off anyway..

I'm afraid I usually run the change wheels to the gearbox dry. I have been meaning to take the cover of the gearbox and use moly grease on the gears for about 13 odd years since I bough the lathe. I have put a touch of cycle oil on them at times – all wrong and have wondered about using chain lubricants maybe waxy types on the change wheels. Boxfords have a separate feed drive so the lead screw doesn't receive much attention or need it really as I don't screw cut all that often. I just make sure it's clean. Rags usually have some oil or the other on them.

John

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