Thread: lathe coolant

Depending on the amount of coolant you want to use and whether you need to be able to reclaim it you have a few options.

Cheapest would be a Soft drink bottle with a small hole in the lid,squirt it on the part your machining.

Next would be to use an old Milo,Coffee or Baby powdered milk tin or similar,but a hole in the side of it near the bottom,attach a small Ball Valve or tap,bit of tubing to direct flow.You would need to make some type of stand at the rear of your lathe to hold the tin.

Next would be a small pond pump sitting in either a plastic bucket/drum or some type of plastic container,b plumb it up similar to the tin,you would need a pump that would lift a minimum of 1metre,place a hole in the tray of your lathe with some type of filter so not to much rubbish can get back to the resivoir and pump.

Next would be to by a purpose made system from one of the machinery dealers.

Pipeclay has covered your options.
In the old days before plastic bottles & electric pumps an amateur turner could buy one of these for use on his treadle lathe.
lathe can.jpg
'WELLS LATHE CAN'
BTW I don't use it balanced on a jar of beeswax polish, just there for the pic.!
Mark

Two solutions I use.

I use an old fuel tank to feed cutting oil into the lathe, the oil then drains into a drum under the lathe and is periodically filtered and re-used.

The other solution, if you want to use soluble oils, is to get one of the el-cheapo parts washers. I use one on my hacksaw but it could be easily adapted to use on a lathe.

IMGP0075.jpgIMGP0078.jpg

Here's mine.

Thanks for your input blokes, also came across another idea similar to bobl's from tongles. Might use bobl's and tongles pond pump idea I think. Thanks again.

Originally Posted by alesandro

Thanks for your input blokes, also came across another idea similar to bobl's from tongles. Might use bobl's and tongles pond pump idea I think. Thanks again.

Make sure you use magnets to collect fine swarf otherwise the swarf will clog the aquarium pump which contains a permanent magnet and cleaning it out is not a pleasant job. I have a similar coolant system set up on my BS (which makes more fine swarf than a lathe) and I had to install extra magnets onto the metal drip tray to make it magnetic otherwise the pump would stop working after only a few dozen cuts.

I found that water/oil emulsion coolant as used in industry will quickly get rancid in a home shop setup that only gets on/off use (ugly smelling bacteria seem to thrive in it after a short while). It also stains your machine tools. Hare and Forbes sell a cheap solution, something like a gravity fed miniature camping shower bag. Much better for the on/off usage typical in a home shop is something like ATF or Hydraulic oil, if a true flood coolant is what you are after. It does not go off. But it needs a proper coolant pump setup as it otherwise can get messy.

Another alternative is using a water spray mister. These are commercially available misting systems that use compressed air and water (healthy), or sometimes an organic mixture. The latter is not liked in industry because you breathe the very fine organic vapors, but for home shop use should be fine with good ventilation. Google up "Kool Mist" and similar products. Chris

Chris is right, the soluble oil coolant will go rancid over time. I use a full synthetic coolant made by Carlingford, i'm not sure on the exact name right now but can check tomorrow. It will not go off or scummy and has the bonus of being a clear greeny colour so visibility is better.

Originally Posted by alesandro

Thanks for your input blokes, also came across another idea similar to bobl's from tongles. Might use bobl's and tongles pond pump idea I think. Thanks again.

I have a pond pump running coolant for my BS. It runs into a 5 litre plastic container at the moment although I have plans to change this for a 15 litre bucket with a lid. I have the pump sitting just off the bottom with a stainless step about 10mm high. This will be higher when I change to the bucket. This step (perforated) stops gunk from the bottom from being sucked up, I hope. I also have magnets under the tray and a garden watering type filter at the coolant tray level. This has worked for me for a long time except sometimes I have to grab the hose and jiggle the pump up and down to shake off the coagulated gunk from the coolant. I am told that synthetic type coolant does not go off. I hope this is true.

Dean

Another vote for ATF, I recently changed both my mill and lathe over to it. The soluble oil was forever evaporating and staining and rusting everything and it is not cheap. I made up a good filter system using a Holden oil filter and picked up 60 litres of clean used auto transmission fluid for no cost. I filtered it and cleaned out both machines ( what a job) and it is all OK now.
Bob

Originally Posted by cba_melbourne

I found that water/oil emulsion coolant as used in industry will quickly get rancid in a home shop setup that only gets on/off use (ugly smelling bacteria seem to thrive in it after a short while). It also stains your machine tools. Hare and Forbes sell a cheap solution, something like a gravity fed miniature camping shower bag. Much better for the on/off usage typical in a home shop is something like ATF or Hydraulic oil, if a true flood coolant is what you are after. It does not go off. But it needs a proper coolant pump setup as it otherwise can get messy.

A big disadvantage of ATF or HO is their poor specific heat capacity (< quarter of that of water). Where a large surface area is involved extra volume of fluid helps but where cutting tips are small it may not work as well.

Another alternative is using a water spray mister. These are commercially available misting systems that use compressed air and water (healthy), or sometimes an organic mixture. The latter is not liked in industry because you breathe the very fine organic vapors, but for home shop use should be fine with good ventilation. Google up "Kool Mist" and similar products. Chris

Even with water vapour systems, good ventilation will be needed to stop things corroding in a home workshop. One thing about most home workshops is that they are usually much smaller in volume than commercial shops so just one mister can saturate the air in a small home workshop very quickly.

I've had my Lathe cooling system for over a year now and given it only gets used a couple of times a month I am very pleased that it has not developed a smell.
I'm using H&F synthetic cutting oil in water which supposedly has excellent anti bacterial properties but I also run the pump at full speed (and tap off the pressurise side of the loop) so whenever it is used it get vigorously agitated. The affect of this would be to over oxygenate the fluid which will promote aerobic bacterial growth but suppress anaerobic bacterial growth which turns any Sulphur present in lube oils and in water into H2S (rotten egg gas). However, it does over a period of a few months develop a horrible looking scummy layer on the top of the reservoir which I scoop off.

Here is a very readable PDF about cutting fluid that some might find useful

Another system I have heard about is a vortex tube - uses compressed air to make two air streams one hot and one cold. At work in the engineering dept they are experimenting with using this for cooling machine tools.

> Another system I have heard about is a vortex tube - uses compressed air to make two air streams one hot and one cold. At work in the engineering dept they are experimenting with using this for cooling machine tools.

Trouble is, a vortex tube uses huge volumes of compressed air to make a minuscule volume of cold air. Compressed air is expensive (considering not only electricity, but small low cost compressors as used in home shops have a short life if duty cycle is too long). Plus compressors are noisy. I think that are the reasons why vortex tubes are not used commercially, despite being very simple low cost devices without moving parts. Chris

Originally Posted by cba_melbourne

. . . Trouble is, a vortex tube uses huge volumes of compressed air to make a minuscule volume of cold air. Compressed air is expensive (considering not only electricity, but small low cost compressors as used in home shops have a short life if duty cycle is too long). Plus compressors are noisy. I think that are the reasons why vortex tubes are not used commercially, despite being very simple low cost devices without moving parts. Chris

Yep - all good points.

Originally Posted by krisfarm

Another vote for ATF,

Bob, does it smoke?