Lathe Coolant system or Cutting Fluid, What do I need

[Investigator]

I don't know what I need, if anything. I have read about flood coolant systems for lathes, and I know there is a difference between coolant and cutting fluid. My question is do I need some type of coolant system? IF so what kind? What about cutting fluid, so far I'm dripping it onto the work from an oil can.

My lathe is a 12" Logan. I have been working with aluminum using WD-40 as cutting fluid, and I have been using 17-4 Stainless (which cuts much better than anything else I've used) and using 30w oil on it. I have tried cold-rolled steel with the 30w also.

So please tell me the pros and cons of using coolant and cutting fluids. I don't even know how much I don't know.

Scott

 

[Bob Korves]

Flood coolant makes a mess, otherwise is the best. The water based coolants also need to be taken care of, they get bacteria growing in them and stink badly. Definitely requires maintenance. Flood type coolants can also be squirted on from a squeeze handle plastic bottle manually, or from a air powered mister unit. Some people flood cool using cutting oil in the system. Can be a huge mess, and oil does not hold as much heat as water does. A simple air blast stream on the tool and work can also help cool the job.

Coolant is needed for maximum cutting performance, speed, and metal removal quantity. Many or most hobby machinists will just use cutting oil to improve the surface finish and slow the process down enough to keep the heat down to an acceptable level. We are not getting paid by the piece. I would suggest to try using an acid brush for applying the oil to the part, perhaps easier to get the oil where you need it.

 

[Investigator]

Flood coolant makes a mess, otherwise is the best. The water based coolants also need to be taken care of, they get bacteria growing in them and stink badly. Definitely requires maintenance. Flood type coolants can also be squirted on from a squeeze handle plastic bottle manually, or from a air powered mister unit. Some people flood cool using cutting oil in the system. Can be a huge mess, and oil does not hold as much heat as water does. A simple air blast stream on the tool and work can also help cool the job.

Coolant is needed for maximum cutting performance, speed, and metal removal quantity. Many or most hobby machinists will just use cutting oil to improve the surface finish and slow the process down enough to keep the heat down to an acceptable level. We are not getting paid by the piece. I would suggest to try using an acid brush for applying the oil to the part, perhaps easier to get the oil where you need it.

I assume by flood coolant we are talking about water soluble solutions? What effect does this have on the machine? Any rusting issues?

 

[Ken from ontario]

I recently decided to try one of those cheaper misters we often see on ebay/amazon so I ordered one and also the water soluble coolant for it, have not received my order yet but I'm thinking even if the mister does not work as it is supposed to or if it makes a huge mess, I could still use it as a blower to cool the workpiece down and blow the chips and the smoke away away so for the amount of money involved, I think it's worth a try.

I can manage with cutting oil when machining Aluminum but I get a lot smoke when cutting steel, and the level of smoke gets so dense that I have had to stop 3-4 times and open the front/back doors to let the smoke out so I can breathe, I do dread the thought of machining steel for that reason.

 

[Jimsehr]

For production flood. For home shop I use a small air brush that I bought from Harbor Fright for 10 bucks. Works good when drilling deeper holes. Only holds a small amount of coolant . It has a small glass jar.

 

[Ray C]

If you do machine work on a regular basis and do not have good ventilation, using oil will eventually lead to health problems. I didn't think it would happen to me but, it did -and I don't smoke cigarettes or cigars either.

Flood vs Mist. This reminds me of the age-old battle between Wedge or Piston tool-post systems or, oil-change intervals for your car or, what brand of oil filter is best. Pick one and stick with it. Be mindful that if you are new to machine-work, don't expect a coolant system to solve all your problems and give you a mirror finish on everything you touch.

That said, I personally used to use just oil. After 5 years of that out in my garage, I developed bronchitis and was bordering on COPD. I used flood coolant for a couple years and found it to be messy and a lot of work -and it often didn't cool the part down very much at all. About 8 years ago, I switched to a mist-type system and never looked back. Like anything else, it has a few tricks to use properly.

Please check this thread starting at post #20. http://hobby-machinist.com/threads/for-those-who-think-all-pm-owners-keep-pristine-equipment.63921/

Parting shot is: Save your lungs and totally minimize using any kind of oil. I only use it for tapping and thread cutting now.

 

[mikey]

I've been experimenting with Anchor lube because of the smoking issue with cutting oils. So far, it seems to work pretty well for most things I turn and no smoking issues. Anything that aerosolizes a fluid gets into the air so no coolant or mister systems for me.

 

[Ray C]

Oh, forgot to mention about the difference between coolant and cutting fluid. For the purposes of most lathe, mill and grinding work on most kinds of common metals, the two things are different animals. Coolant's cool things and have additives to keep algae down, keep rust under-control and not dissolve lubricants (such as way oil) too badly. Cutting fluids are often sulfur-based but can be other forms of fairly strong chemicals. They make no attempt to prevent algae or otherwise be nice to you or your machinery. Cutting fluids are typically used for high pressure, slow-speed operations. There are some fairly complicated interactions at the level of molecules when metal is torn away by carbide or cut by sharp HSS but in either case, by adjusting the tool bit position, the type of tool bit (carbide or HSS) or the speed/feed, you don't need cutting fluids for standard lathe, mill or grinding operations. Lubricants (which are different than cutting fluids) on the other hand, can help with general machining but, the down-side is the smoke -which will eventually cause lung issues. In my case, I'm OK with using mist-type solutions because, the main ingredients are also used in various food-processing additives. They all have an MSDS Health rating of 1 (on a scale of 0-4). Most motor oils and the ingredients therein have an MSDS health rating of 2 or 3.

Regards

Ray C.

 

[Investigator]

If you do machine work on a regular basis and do not have good ventilation, using oil will eventually lead to health problems. I didn't think it would happen to me but, it did -and I don't smoke cigarettes or cigars either.

Flood vs Mist. This reminds me of the age-old battle between Wedge or Piston tool-post systems or, oil-change intervals for your car or, what brand of oil filter is best. Pick one and stick with it. Be mindful that if you are new to machine-work, don't expect a coolant system to solve all your problems and give you a mirror finish on everything you touch.

That said, I personally used to use just oil. After 5 years of that out in my garage, I developed bronchitis and was bordering on COPD. I used flood coolant for a couple years and found it to be messy and a lot of work -and it often didn't cool the part down very much at all. About 8 years ago, I switched to a mist-type system and never looked back. Like anything else, it has a few tricks to use properly.

Please check this thread starting at post #20. http://hobby-machinist.com/threads/for-those-who-think-all-pm-owners-keep-pristine-equipment.63921/

Parting shot is: Save your lungs and totally minimize using any kind of oil. I only use it for tapping and thread cutting now.

Just to understand better.....

On the cooling mist system, does it have it's own air pump or is it hooked up to a regular air compressor in the shop which also has to run?

 

[Ray C]

Just to understand better.....

On the cooling mist system, does it have it's own air pump or is it hooked up to a regular air compressor in the shop which also has to run?

They come in all kinds of configurations. Most of the systems run off typical shop compressed air. If you look at that thread I referred you to, I showed some links to misters that cost about 10 bucks. I run mine at 40-50 PSI and the air-flow is so low, I'd say I have leaks in other fittings in the system that waste more air than my mister does. FWIW, I use Kool-Mist branded solution. Comes in 8 oz bottles. Mix 1 cap to a quart of water. A quart last me several days to a week of heavy lathe use.

These are my personal thoughts/opinions/practices. Your mileage may vary and I highly encourage you to experiment. Like I said, the only thing I really encourage is that you stop using oil lest you damage your health.

Regards

Ray C.