Thread: lathe coolant

Dont you mix your oil and water together before adding to your sump?

I remember that coolant started to smell after a week. But that was in the 70ies.

I had coolant that kept good for several years after being mixed (and never filled up etc.).

There are a few things you should know about coolant:
* Thoroughly (and I mean thoroughly) clean the tank before starting with your fill. You don't want to infect your coolant with the gremlins sitting in the tank and waiting for fresh food.
* Let air come to the coolant. This includes skimming the oil off of the top.
* If used rarely, install an air bubbler.
* By all means, buy a refractometer and keep the mixture well above the recommended minimum mixture. Keeping the mixture rich enough, chips do not rust. But it doesn't hurt to clean your lathe/mill (I'll try to remember that).
* If you milled/turned rusty stock, you really should clean your mill/lathe, as these chips really start rusting over night.
* As soon as your coolant stares at you, you have to dispose it and clean the tank. Washing soda does a good job.

I have bought the cheaper coolant oils, and see no difference in how long the stay good.


Nick

Originally Posted by pipeclay

Dont you mix your oil and water together before adding to your sump?

If I remembered what it was like to mix I would but I forget and just poor it into the coolant tray. Maybe next time lol. It is all mixed in now. I need to change the 5 litre container (miniature 20 litre style) for a bucket with removable lid. Then it will be easier to add water / oil to the container direct. The container has the top cut on three sides only so is not easy to get into. I believe I mentioned this change to the container in my thread on bandsaw update which I tried to find earlier but the search returned zero results. Not sure what is happening there. Metalwork forum is still not sorted fully after the software update.

Dean

I don't have any real experience with coolant tanks, but I do have forty odd years worth of working around the exact same bacteria in jet fuel tanks, especially those on airplanes used infrequently. All hydrocarbons attract, and include, free water. That's true of diesel fuel, dry cleaning solvents, and cutting coolant. The bacteria which provides such an aromatic treat lives in the meniscus between the hydrocarbon and the water...that tiny little membrane that forms between the two disparate components of the mixture.

That particular organism is anaerobic, so it does not like aeration. An aquarium bubbler does wonders. It also does not like UV light. Who does? A black light shining into the reservoir will do wonders in killing off entire generations. These two simple additions to a coolant tank should make flood coolant a viable home shop option.

I have both schemes fitted to a mobile pump/tank, but it is still unused. My goal is to have a 4l tank on wheels which will service the mill, lathe and grinder as needed. I expect that the mill and grinder will use 90% of that capability.

Greg.

Originally Posted by Greg Q

I don't have any real experience with coolant tanks, but I do have forty odd years worth of working around the exact same bacteria in jet fuel tanks, especially those on airplanes used infrequently. All hydrocarbons attract, and include, free water. That's true of diesel fuel, dry cleaning solvents, and cutting coolant. The bacteria which provides such an aromatic treat lives in the meniscus between the hydrocarbon and the water...that tiny little membrane that forms between the two disparate components of the mixture.

That particular organism is anaerobic, so it does not like aeration. An aquarium bubbler does wonders. It also does not like UV light. Who does? A black light shining into the reservoir will do wonders in killing off entire generations. These two simple additions to a coolant tank should make flood coolant a viable home shop option.

I have both schemes fitted to a mobile pump/tank, but it is still unused. My goal is to have a 4l tank on wheels which will service the mill, lathe and grinder as needed. I expect that the mill and grinder will use 90% of that capability.

Greg.

Very interesting information. Jet Fuel? But then I recalled about bacteria that can survive in the most inhospitable locations. Boiling water under the sea and radioactive locations included I believe. I think both of my lathes have a coolant sump built into the tailstock base. A bit hard to get at right now. When the new lathe is installed it will be further out from the wall to allow access to the rear.

I was thinking about a single tank for everything last night. Will look into it when everything is setup.

Dean