Need a Coolant skimmer, what to do with tank baffles?

I have an old box way quick turn 10 and im getting quite a build up of way oil on top of the coolant. Id like to add a skimmer, but this lathe has a bunch of baffles that will trap the oil? How do I deal with this? Im thinking of sawing a notch in the top of each baffle, maybe a 2 inches wide and 2-3" deep so the oil can make its way through the chambers. Anybody see why this could be a bad idea?

Maybe then I could add a skimmer to the last chamber and it would get most of it. This machine isnt used for high volume and doesnt have a conveyor so I could probably fit a belt skimmer in the last chamber. Any suggestions? How did people deal with this on this problem on these old machines? If a conveyor was being used there would be no place at all for skimmer, and the baffles would block it from flowing anyway.

Make holes to let oil flow through.

mmurray70 said:

I have an old box way quick turn 10 and im getting quite a build up of way oil on top of the coolant. Id like to add a skimmer, but this lathe has a bunch of baffles that will trap the oil? How do I deal with this? Im thinking of sawing a notch in the top of each baffle, maybe a 2 inches wide and 2-3" deep so the oil can make its way through the chambers. Anybody see why this could be a bad idea?

Maybe then I could add a skimmer to the last chamber and it would get most of it. This machine isnt used for high volume and doesnt have a conveyor so I could probably fit a belt skimmer in the last chamber. Any suggestions? How did people deal with this on this problem on these old machines? If a conveyor was being used there would be no place at all for skimmer, and the baffles would block it from flowing anyway.

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You need to understand why those baffles or more correctly weirs are in the tank. Their function is to increase the dwell time of the coolant from the tank inlet to the coolant pump intake. They also act as a gravity separator at the same time.

If you had a conveyor, the conveyor itself would act as an oil skimmer greatly reducing your problem.

If you are only turning steel, drilling holes or cutting slots will not matter a lot. However if you are ever going to turn aluminum, you will end up with a lot of floaters getting into the rear tank section and will likely cause problems.

The real tramp oil is going to collect mainly in the first tank section by the inlet.

The other tank sections will mainly collect suspended tramp oil. This usually separates out after the machine is turned off and the coolant sets for awhile.

One way around this is to use a side stream oil separator system. They are usually constructed from a 5 gal. bucket with a turned down type outlet, acting as a gravity separator. You can either buy one or if you are handy make one fairly cheap.

The belt systems do work well but they also pull out a lot of coolant with the tramp oil if they are allowed to run continuously.

Ziggy2 said:

You need to understand why those baffles or more correctly weirs are in the tank. Their function is to increase the dwell time of the coolant from the tank inlet to the coolant pump intake. They also act as a gravity separator at the same time.

If you had a conveyor, the conveyor itself would act as an oil skimmer greatly reducing your problem.

If you are only turning steel, drilling holes or cutting slots will not matter a lot. However if you are ever going to turn aluminum, you will end up with a lot of floaters getting into the rear tank section and will likely cause problems.

The real tramp oil is going to collect mainly in the first tank section by the inlet.

The other tank sections will mainly collect suspended tramp oil. This usually separates out after the machine is turned off and the coolant sets for awhile.

One way around this is to use a side stream oil separator system. They are usually constructed from a 5 gal. bucket with a turned down type outlet, acting as a gravity separator. You can either buy one or if you are handy make one fairly cheap.

The belt systems do work well but they also pull out a lot of coolant with the tramp oil if they are allowed to run continuously.

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The belt systems do work well but they also pull out a lot of coolant with the tramp oil if they are allowed to run continuously. - This is pure fiction, belt speed is designed in a way that gravity pull coolant down much faster then machine oil , and coolant never reach the spot where oil is separated into a container. Coolant doesnt mix well with oil, it stays coolant , dirty but coolant.

Ok I think I will cut notches in the baffles/weirs/whatever they are. I think im just going to make 2 cuts with a sawzall and bend down a tab making a square notch, worst case scenerio I can just bend it back up and weld it if i want to go back to original.

If you run a skimmer with a separating tank you wont loose any coolant at all. Heres one I made for my mill. Skimmer picks up oil/coolant mix and scrapes it into a tank, the oil stays on top and coolant moves under baffle into the chamber on the right and then down through the hole back into the tank. Once the oil builds up a 1/4" thick or so it overflows into the oil pan. Been using this for a couple years now and it works amazing! It will fill that tray, probably half a gallon without a single drop of coolant. This setup was really cheap too. Just a cheap 24v gearmotor that runs off a timer for a few hours every night. Was a pain making the tank, but it works so well that im still very happy with it.

Why don't you put the skimmer in the first compartment and see how that works. Most oil should end up there and if you remove it before it can spread you may solve 90% of your problem without cutting into the tank. If it doesn't work like you want then cut the tank.

Well the first compartment is right under the chuck, so not really a good place for a skimmer. All the chips tend to build up there. Only place somewhat free of chips would be right back at the end.

mmurray70 said:

Well the first compartment is right under the chuck, so not really a good place for a skimmer. All the chips tend to build up there. Only place somewhat free of chips would be right back at the end.

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You can use the baffles as a skimmer, kind of like the separating tank on your mill.

You cut a notch in the top of each baffle extending just below the nominal coolant level in the tank. Just let the surface flow across the baffle. Offset the notches, so it's like a labyrinth arrangement. Sounds like that's what you had in mind anyway.

Now, place a small aquarium pump in the last chamber before the pickup. put a piece of wire mesh window-screen zip-tied over the inlet to keep the swarf out. Run some vinyl hose from that little pump under the baffles all the way through to the first chamber (nearest the chuck).

That little pump will move coolant to the first chamber causing your surface to flow over the notches in the baffles. Since most oil will separate out to the surface, it will flow into the last chamber.

Put your belt skimmer in the last chamber.

Make sure there's a swarf screen on your coolant pump, or a removable swarf-gate blocking chip-flow to that portion of the last chamber.

I use this system on my VMC with a shop-made belt-skimmer. Those aquarium pumps are about $15 from places like wal-mart or the pet store.

My skimmers are 10RPM and use the old L-100 belts off my Mazak QT-10 ball-screws. The motors are just shaded-pole AC motors with gearboxes on them designed for a pellet stove auger. The whole works is less than $50 to put together.

These are open bottom baffles or bottom/top/etc.?
Ass-u-ming a bottom flow out of #1 the skimmer needs to go in the first if you can fit it.
I would not short circuit the system except as a last resort.
You will kill the drop out time and any notches or holes have to handle level as coolant evaporates.
Do you want to have to control coolant level within a 1/2 inch or so day after day?
If not and but you still want all oil in the end just get out the gas hatchet and remove the baffles.
Bob