Kool Mist type lubricators/coolers?

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Diesel II
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Kool Mist type lubricators/coolers?

Post by Diesel II » Wed Apr 09, 2008 7:48 pm

I was looking at tool misters. I have a few questions about “Kool Mist” type systems. Since they use water do they cause rusting of the machines if not used daily? Are these better for the home shop than the old type cooling oil pumps that flooded the tool? What brand is the best bang for the buck. I may spend some of George’s money to help the economy when I get my taxes done.

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Post by sch » Wed Apr 09, 2008 8:25 pm

Most coolant, flood or mist is water based, hence must be cleaned up
periodically to avoid rusting. Misters require an air compressor
and can be noisy (high frequency type noise) and the mist is not
something you want to breathe so scavenging systems are advisable
to keep the shop clear of mist.

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Post by Michael_Moore » Wed Apr 09, 2008 8:41 pm

You might look at the Trico Micro-Drop system. They sell a vegetable-based biodegradeable lube for it too. I bought the two nozzle version so one can be largely just blowing the chips away while the other delivers lube in small drops to the too.


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Post by mechanicalmagic » Wed Apr 09, 2008 9:15 pm

I worked in a shop that used a lot of Kool Misters.

I never saw evidence of rust THERE.

So, I bought one for home, mix about 2x suggested strength. And, if I am lax about cleaning up, I think I find VERY light rust.

I can't suggest cost effective alternatives.

Mine (on the mill) is wired thru solenoids, so if the quill is off, so is the air, AND the coolant flow. Stops most of the drooling. I have a little switch on the back of the quill switch, that connects the quill and the Cool Mist on/off.

Every day I ask myself, "What's the most fun thing to do today."
9x48 BP clone, 12x36 lathe, TIG, MIG, Gas, 3 in 1 sheetmetal.

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Bill Shields
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kool mist

Post by Bill Shields » Wed Apr 09, 2008 10:16 pm

I get a bit of rust if I don't mix the coolant to the correct proportions.

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Post by JimGlass » Wed Apr 09, 2008 11:27 pm

Here is a drip coolant system I made. There are two lines, one for coolant and one for air. Coolant is dripped onto a low pressure stream of air. The stream of air propels the coolant onto the tool. There is no nozzle, just two lines. Each line has a tiny valve to regulate the flow of coolant and air.

Here is a close up. The coolant comes out through the upper line and air out the lower line. Notice how the coolant is attracted to the air and the air propels the coolant.

Below is the coolant tank, if you want to call it that. The tank is a
2" X 18" pipe nipple. There is an air regulator at the top set at about
5 PSI. The coolant comes out the bottom of the tank.

I made this system to spray WD40 on endmills for machining aluminum.
The mister is turned on and off through the CNC program using M07 codes in the program. The coolant may turn on and off several times before a workpiece is finish. This saves on compressed air and coolant because just the right amount is applied. Applied so sparingly the chips absorb the spent coolant so no recovery system is required. I can machine aluminum all day with 1 quart of WD40. True spray misters can create a coolant fog in your shop because the coolant is atomized and discharged under high pressure air.

If you use water for coolant you must add a rust inhibitor to the water to prevent rust.

Tool & Die Maker/Electrician, Retired 2007

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Post by HotGuns » Thu Apr 10, 2008 12:38 am

I use Kool Mist systems at work everyday.

We use the 110 pound plant air supply.

If you use the mister heavy enough to let water puddle up and stay there, it can rust. We dont have that problem, as we always blow off and at least wipe off the machines until the end of the day when we clean shop.

We generally dont have a problem fogging the place up either. If you you the mister as its meant to be, you wont have a problem with water puddling up. It evaporates as it goes, leaving very little water laying around.

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Post by millman5 » Thu Apr 10, 2008 10:13 pm

I like the Wesco units. http://www.wescotool.com/prod1.htm For a cost effective entry level setup take a look at the 90M

It's not a perfect system but it's what I started with. I really don't think their nozzle design, as far as atomizing the coolant can be beat.

The "2" control knob units give you very exact control over fluid vs. air & dont drip when shut down. In my opinion valves on both air & fluid are a must. The single valve units meter only air & the couple I tried threw out so much fluid that by the end of the day you were tromping around in a swamp. I literally made spous to hang gallon buckets on each end of the milling table to catch fluid run off then pour into one of my lathe sumps. If your tank is higher than the mist nozzle a single line unit will also siphon your tank dry in a few hours. get your tank to low & it will not siphon lift the fluid to the nozzle.


(1) Coolant/air line not long enough to suit me.
(2) Drill curls are death to the line if tangled.
(3) Replacement line to expensive.


(1) Most inexpensive dual control mist unit I could find.
(2) Control of mist stream from so light you have to hold something in front of the nozzle to see you are getting fluid. To very heavy wetting. So much that it will saturate everything downstream.
(3) Very effective refrigerant like cooling for most manual milling machine operations for pennys of coolant cost.

Eventually I ended up building my own mist unit using the nozzle off one of my destroyed lines. I soldered a couple short pieces of small brass tubing to their nozzle. soldered a short piece of 3/8" Cu. tubing to the outside to slide the braid over & heat shrink mount. Used 1/16" nylon tubing to make the hose assembly as long as I wanted. Bought some braided cover very much like the original hose cover from an electrical supplier. Used heat shrink to connect the braided cover to the nozzle. 2 brass needle valves from McMaster Carr. Removet the stamped "T" valve knobe & used a couple brass nuts for knobs. Use a windshield washer jug for the tank remotely mounted. placed the valves on my DRO arm.

End result: Super controlable system, Tank completely out of the way, valves within easy reach, durable enough to withstand moderate abuse.

I have absolutely no rust problem as long as coolant is mixed a bit rich & don't leave a fixtuer, vice etc bolted to the table after use. Even then it's not rust in the traditional sense. more of a stain that goes away eventually with normal use of the mill. The staining you can see in pic 3 is coolant residue that can be removed with an industrial cleaner.
My mist system 001.jpg
My mist system 002.jpg
My mist system 003.jpg
My mist system 004.jpg
My mist system 005.jpg
My mist system 006.jpg
My mist system 007.jpg
If it works Don't fix it....

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