Coolant types for a lathe

[Si Titor]

Is it better now days to use just cutting oil or suds (cutting oil water mix)?, I am guessing the answer will be just cutting oil.
This will be pumped with a 'coolant' pump sorta.

 

[Hmangphilly]

Is it better now days to use just cutting oil or suds (cutting oil water mix)?, I am guessing the answer will be just cutting oil.

If you dont use the machine much , the water based stuff can go rusty if you dont wash it all away

Youll need decent splash guards too else it goes all over

 

[terry1001]

I mainly turn aluminium so use a bit of WD40 if necessary which is not very often. I do have the bits for a spray system but haven't felt the need for it so it's not been assembled. I did use to have a couple of lathes with soluble oil cooling but far too often I'd come into the workshop to be greeted with a foul smell from the colant which would go off for no apparent reason.

 

[Hmangphilly]

I mainly turn aluminium so use a bit of WD40 if necessary which is not very often. I do have the bits for a spray system but haven't felt the need for it so it's not been assembled. I did use to have a couple of lathes with soluble oil cooling but far too often I'd come into the workshop to be greeted with a foul smell from the colant which would go off for no apparent reason.

bacteria in the old days Terry

 

[Jesterdog]

Lathe doesn't get enough use, wish I could find the time
I have a proper suds pump, used with soluble oil. Managed to get container volume down to about 2 litres by adding stones, as when I go to use it, it needs changing. So not too expensive.
If only minor work then either wd40 or oil

 

[KWK1]

Can't think of a reason to use coolant on my light lathes. Not worth the mess to me. If I need cutting oil for anything I paint it on with a brush very lightly. No need to make a big mess all over the machine and wall. Just hold an acid brush with oil on the parting tool or form bits.
Last evening I drilled a deep hole (4 1/2 inches) in a part and it got heated from the friction. No biggie, I just took my time. Not running production here. The quill in the tailstock only reaches about 2 1/8 inches.

Using HSS makes a difference. A lot less friction and heat. That's what light lathes are designed for anyway. Best performance with low HP and modest spindle speeds of these flexible vintage machines. Single wall aprons and small compound slides.
Yes. I can take .100 in mild steel but that's pushing it, huh? Fun to watch the long curly chips peel off, though. Without any coolant of course. Using HSS

 

[Lordy74]

I use miracut and wd40 as and when just applied from an old dog shampoo bottle of all things that happens to have a rather fine nozzle perfect for the viscosity of the oil or just applied with a small brush.

 

[Tricky-Dicky]

I just use a mix of engine oil and white spirit in a small squirt bottle and also a brush.

 

[Anchutz]

On mini lathes Ct80 is excellent on mild steel, just a drop every pass, wd for alloy.

 

[Mr Fettler]

In work we use oil on some and suds on others.
If my choice I'd go oil.
Can stay in the machine for years, doesn't go off, protects the machine, less chance of an allergic reaction, less smell, and you can get it filtered clean again.
Of course, it's a lot more expensive.

 

[Mr Fettler]

BTW, if you do go for suds, we run a 7% mix, but could be different with different makes.

 

[KWK1]

I only use cutting oil for a few operations with steel on a light lathe. Threading or form bits, knurling, drilling, and parting. You don't need it for anything else. If you're not getting a good finish it's not because of oil. It's because you don't know how to grind a proper cutter. Was the first thing to learn at school when I started 52 years ago.

 

[Lordy74]

My thoughts are that using a small amount of cutting oil protects the tool giving a bit more life to the edge. Same with drills . It aids cutting and puts that little less strain on the machine . Can't do any harm.