Thread: lathe coolant

Here is my vote:
Good old long proven water with soluble oil.
It does not stare at you after some time if you let access air. Agitating it from time to time is also good. Some even have an air bubbler (aquarium stuff) that is switched on by a timer once every few days. To avoid rusting, you really should buy a refractometer and check whenever you fill up. If you get too low, you get rust. I stay over 5%, even if they say 3% are enough. More oil doesn't hurt that much.

I have tried mist cooling (from Noga) and that is just crap in my eyes. The smaller the mill gets, the less it works (if it works at all). I once had to mill a pocket for an O-ring with a 2 mm mill. I broke 5 of them in the fist few cm. After switching to coolant (water/oil), I have cut 1 m without breaking it. That stuff doesn't wash out chips, it only helps sticking the chips.
And, it doesn't really cool, it only blows away chips.

Pure oil is often used on Swiss lathes. But they always do have a full enclosure and use it generously. I wouldn't like the mess on the floor with a conventional lathe.

OTOH, coolant helps best, if you really FLOOD the work. I wouldn't like that either on a manual lathe. So a few drops of a good cutting oil is an option. But then, some carbide inserts do not like oil at all. They only work dry or with coolant.

That didn't help much. Maybe helped to confuse a bit more.

Buy a squirt bottle and use water+oil on a manual lathe.


Nick

One way to pump the coolant that i was quite impressed with was to machine an eccentric cam that mounts on your lathe feed screw and operates the lever of an old diapragm fuel pump from a car.
I too have had the problem of bacterial growth in coolant tanks but can report that neither the oil sold by Hare and Forbes nor Millicent B soluble screwing oil seem to suffer from this issue.

Originally Posted by cba_melbourne

I found that water/oil emulsion coolant as used in industry will quickly get rancid i

how long does it take before it goes off Chris?

Hi all,

I have been watching this thread with much interest. I am yet to use any coolant on any of my machines but I am keen to experiment to see if it suites my needs.

WRT lathes, when the coolant falls onto the chip tray, how do you stop it seeping between where the lathe bed bolts down and sandwiches the chip tray?

I'm always finding oil (from the norton gearbox) seeping through and ending up inside the cabinets. Should I silicon a bead around the base of the lathe bed?

Cheers,

Simon

Originally Posted by simonl

I'm always finding oil (from the norton gearbox) seeping through and ending up inside the cabinets. Should I silicon a bead around the base of the lathe bed?

me too ...although it does have a benefit..the oil goes all the metal buts I have in the cabinet area which helps prevent them from corrosion...dont think coolant will do this if left attended for a long time

I have thought about cleaning with acetone and then using silicone ...but????

I have seen it highly recommended on another forum to silicon around the bases of the bed before assembling.
The factory tray is not really coolant friendly, it really needs a new one made up, but can be made to work.
You could pop rivet a few pieces of sheet angle across the headstock end to stop coolant flowing up there, and then silicon around the bases, that way you wont have to pull the lathe off them and re level it all.

Dave

Originally Posted by eskimo

how long does it take before it goes off Chris?

It has been 20 years since I last tried to use oil emulsion at home. As I remember it took less than 2 months to develop this ugly smell up from the basement into the house. And when I found out it not only smells but can also affect health, I decided never to try again. Now in the meantime things may have changed, as "synthetic" emulsion oils have become available (at an affordable price, they existed already back then but were too dear). However, I am still not sure how exactly these new "synthetic" oils prevent or suppress the growth of bacteria. Is it just the absence of mineral or vegetable oil that does the trick, or is it maybe additives in the oil that kill the bacteria/algae/fungi/whatever? If the latter was the case, I would first like to know more about how safe are these biocide additives for me the user (skin contact, fume inhalation etc). Chris

Originally Posted by cba_melbourne

It has been 20 years since I last tried to use oil emulsion at home. As I remember it took less than 2 months to develop this ugly smell up from the basement into the house. And when I found out it not only smells but can also affect health, I decided never to try again. Now in the meantime things may have changed, as "synthetic" emulsion oils have become available (at an affordable price, they existed already back then but were too dear). However, I am still not sure how exactly these new "synthetic" oils prevent or suppress the growth of bacteria. Is it just the absence of mineral or vegetable oil that does the trick, or is it maybe additives in the oil that kill the bacteria/algae/fungi/whatever? If the latter was the case, I would first like to know more about how safe are these biocide additives for me the user (skin contact, fume inhalation etc). Chris

It sounds like this PDF http://cedarfallsoil.com/_IWRC_mirror/cfm.pdf will be worth a read.
The case studies at the end are a quick summary of improvements obtained with specific practices

Amongst the man things I learned from this document is
- Aeration helps minimize the numbers of Anerobic bacteria which are the ones that make the worst (rotten egg) smell - Auto aeration is easily incorporated into the pump/flow design.
- water quality may be important. Water that contains too high a concentration of stuff that bacteria like (Total dissolved Solids, Sulphur, Chlorine and Phosphorous) should be avoided, consider using even deionized water for this. I use reverse osmosis water in mine.
- The other oils used, lubes etc, can add to bacterial growth. Skimming these tramp oils from the top of the fluid reservoir is recommended. Use of Low sulphide oils will help reduce the rotten egg gas smell.
- filtering of swarf and fines before the fluid is returned to the tank reduces bacterial growth since it reduces surface area which bacteria love.

By the time this bloke sets up his cheap coolant system with infrequent use and has his OH&S and his IES,and his special water and special coolant it should come in under $1000,not bad for a bit of coolant.

I guess UV sterilazation wouldn't work since its not a clear?

Originally Posted by pipeclay

By the time this bloke sets up his cheap coolant system with infrequent use and has his OH&S and his IES,and his special water and special coolant it should come in under $1000,not bad for a bit of coolant.

You've Just killed the romance pipeclay!

Originally Posted by pipeclay

By the time this bloke sets up his cheap coolant system with infrequent use and has his OH&S and his IES,and his spe cial water and special coolant it should come in under $1000,not bad for a bit of coolant.

4l synthetic coolant, $55,
Boiled and or filtered water, cost of filter/electricity,
Pipe, pond pump, fishtank airator, $100?,
Bucket for sump, $10,
Wiring, switch, $20,

Smartarses on this forum.......PRICELESS

Ewan,
what's the name of the clear green stuff you use?

Originally Posted by jack620

Ewan,
what's the name of the clear green stuff you use?

Hi Chris,
I got it wrong befor, it is callington ultra-synthet 971. And it was only $45 for 5l (shelf price not trade). It is used at 5%. I have found it has also really cut down on chips rusting on the machines as well, the lube alloy I did use sent all the chips I left rusty.