Need help with mist cooling system

Hi all, I’m still fairly new to CNC so go easy on me.

I am trying to have a mist cooling system for my CNC. I research and watch videos on what I need.

What do you guys think of my combo? Do I have everything I need? Is there anything that I am missing? Are all of my parts compatible with each other (Threadings, adapter, etc)?

Reference video/post I’ve looked at:

This is my cart at the moment:

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Awesome! You’ll have fun milling metal on your Shapeoko.

First, what do you plan on milling? If aluminum, then for coolant, I would recommend going with a 75/25 isopropanol/water mixture. It will provide not only lubrication but also evaporative cooling and your parts will come off with no oily residue to clean. This is what @Vince.Fab does on this forum but also what Datron CNC does on their machines (except with ethanol, which is similar in performance) and also what I do as well with good success.

I see that you have a quick connect adapter that will go from the air compressor to adapter but you will also need adapters to connect to the tubing. A female union coupling to go onto the quick change adapter and then either a male ribbed nipple or a compression fitting to attach to the tubing. You also might want a pressure regulator closer to the mister unit to adjust pressure quantitatively there but you can always add that later.

Other than that, I think you should be in a good place.


Are you getting 99% IPA and mixing with [distilled?] water to dilute to 75%? Any worry with flammability?

I’ll be milling cast acrylic (mostly), 6061 aluminum, and brass. Maybe some acetal and softwoods in the future.

Would the coolant I picked out work fine for the materials I’m trying to work with? I’m also looking at Kool Mist #77. And I’ll definitely look more into the 75/25 isopropanol/water mixture

Lets go over the parts I have in my cart,
Air compressor (Check)

Mist system (Check)

Coolant (Check)

Tube (Check)

Could you link me the “female union coupling” and the “Compression fitting” that would be compatible with the set up I’m trying to create here?
Would these be it?

Will this all be it? Sorry for the huge links, just want to be safe.

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Hmm okay, I think I got everything figured out. Thank you for your help!

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The mist will obviously not be wanted on some of those materials…acetal, acrylic, wood… The proper cutters will be far more important, and coolant can cause a lot of damage to those plastics (depends on what’s you’re using…)

With brass, chip clearance is most important in my experience, and any lubrication easily provided with a dropper. An air blast works nicely for the purpose, others use really good vacuum setups.

Aluminum is a different animal…yes, mist if you can, but a few drops here and there with a dripper (by hand) actually works quite well. I (of all people!) enjoy the over-kill of a problem, but you might want to just try it out without the additional setup first. Even a simple spray bottle is a pretty adequate “mister” for a lot of work…and a lot cheaper until you’re into what you find as being the bits you really enjoy vs things that you don’t. Endmills for aluminum are kind of specialized as well. Don’t forget that if you’re using any kind of coolant, you’ll want to keep it off your mdf wasteboard if that’s what yours is made of.

I too use isopropyl alcohol, via Home Depot, nothing special. I do not further mix it with water, and no, at the quantities being used, flammability shouldn’t be an issue.


Sorry I haven’t mention about what I’m using to cut these materials. I’ll be mostly using end mills/bits from Datron. Their 4-in-1 End mill and polished edge for Acrylic.

Change of plan, I just found out the air compressor I picked out is inadequate for CNC cooling since it won’t be providing enough pressure.

I’ll be opting with this one instead:

It is aluminum so that means it will be lighter and won’t rust.

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It’s not so much pressure as total airflow without running continuously. My 25 gallon runs “more frequently than I would like” when I use it this way. Incidentally, an oil-less compressor tends to be quite loud, that may or may not be an issue for you.

As you’ve probably noticed, there’s quite a rabbit hole of tooling and support gear to wander down if you so desire!


I have the Cali Air Tools 15gal (15020C) and is ear lovingly quiet compared to a typical air compressor. When I was running a mister, it would usually kick on about every 5-6 minutes if I recall. Annoyingly CAT didn’t really advertise a duty cycle, It does say it has thermal protection which I hadn’t seen it trip, but I didn’t run the mister that often. I just run dry with a dust vac at this point. Though I typically use ZrN single flutes on aluminum, so haven’t had gummy/welding issues. Though have done it to a three flute and two flute and haven’t circled back to try different S&F with them.


I designed this a while back, it bolts to the HDZ. Does not work with Suckit brackets.
Misting Bracket


I buy the 91% IPA since I can buy it at Target and dilute it with water. No real concerns about flammability, you should be misting on just enough for the endmill and not enough to pool up on the part. The fan from the router helps it evaporate and blow it around.


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