Cooling down

So today's annoyingly amateurish question concerns coolants.

Back at school I vaguely remember having to apply a swarf(?) grease with an old brush and am aware that turning and cutting metal will require cooling.

I've seen some using a few drops of what looks like oil on their work administered from a small squeazy bottle or oil can.

As I only have a micro lathe I would probably administer this way rather than an expensive cooling system.

That being said, what should I use? I will mainly be using ally or nickel/brass alloy if that helps.

you shouldnt need any coolant so long as you take light cuts. I rarely use it and when I do I use a small hand held spray with straight water.

I use CT90 Cutting and Tapping fluid most of the time but it's pricey.

Paraffin (from a Garden Centre) is good for Aluminium. Not sure about Nickel/Brass alloys but I turn Brass without any fluids. Carbide tips are all or nothing - don't dab coolant on them because thermal shock tends to crack the carbide.

A lot of the time cooling isn't necessary when taking light cuts. Using coolant regularly keeps tools sharp longer and improves finish though. Heavy cuts are a different story, but they're not a good idea on a small lathe.

Dave

Richard

Light spray of WD40 will assist the cut and prevent any build up on the tool from the ally, or you could buy any of the advertised cutting fluids available, some are used neat and others are soluble in water. there is such a wide choice at reasonable cost on ebay.

Emgee

Richard

I would use a neat cutting oil applied by a small brush for all metals other than brass and cast iron. Obviously, given your lathe, you will not need much. You will find such oil sold in small amounts, 500ml plastic bottles, by model engineering suppliers.

One small advantage with such oils over water or soluble cutting oil is that it will not corrode or mark the lathe.

JA

Except for brass and cast iron(these are cut dry), some form of cutting oil will reduce the load on the lathe, meaning that you could take a little bigger cut, or faster feed. If you try carbide tools, cut dry on all metals.

Ian S C