Fog Buster vs Flood Coolant

It sounds like some people have installed a fog buster type system onto their machine.

Given the issues with drainage, I am also considering this (I’m getting a fully assembled unit, so I cannot put a shower drain into the table).

For those who have done so, how has it been working, and were there any modifications you had to do to the electronics to have coolant turn on and off automatically?


It works well for me. I have a homemade system that is basically a copy of the Fogbuster.

I was motivated to go this way because of prior experiences in trying to keep flood coolant “fresh” on a system that I might not use for a month or more at a time. I’m a hobbyist and not a pro and my CNC machine use tends to be seasonal.

I have the same coolant switch as the flood system (you can easily find them) and have it powering a pneumatic solenoid that turns on and off the compressed air.

what size air compressor do you have? i have a 30 gal oilless and it ran constantly with my old setup.

I have a 3 gallon Makita “quiet series” air compressor rated at 3.5scfm. It runs at about 30% duty cycle when machining. My air nozzle is 1/8" brass tubing (so about 2mm or .090 ID) and I run at about 80psi. This makes a narrow but strong stream of air which is aimed directly at the cutter to clear chips.

I looked through my phone videos and found one where you can see it in action. Sorry about the reflections.

I’ve since increased the length of the nozzle (to make a narrower cone of air), but it works about the same. MQL is 95% chip clearing and 5% keeping a little lube on the cutter.


Amazing thanks! I will also be using it for prototyping and such, so similarly don’t expect to be running it all the time. I’ve seen some videos of the flood coolant and the machine ends up looking like a swimming pool haha…

I might just keep my order for the flood coolant accessories but then get a fog buster as well. Looks like the chip cleanup is significantly easier that way. Thanks!

That’s exactly what I did. I installed the drain kit (but not drain upgrades – though they seem to be very desirable if you run flood) even though I was 95% sure I’d never run flood coolant on the machine.

Cleanup is very easy. I just sweep it all to the front and vacuum up the chips.

Perfect that sounds exactly what I would do!

And it sounds like the fully assembled units have drains installed along with an additional larger drain near the center back to address all the clogs that others are complaining about…so I suppose I should be able to go both ways if I wanted.

@AlexW I’m looking at buying a Fog Buster now…they have a bunch of different sizes…based on the homebrew one that you have - which one would you recommend?

I probably won’t be cutting thaaat many parts…mostly prototyping and one-off job shop stuff here and there.


I’ve never used a real one, but if I were buying for my machine I would probably get the “half-gallon”. The “mini” might be good enough too, it takes a long time to go through coolant and adding more to the canister shouldn’t be hard.

I have a single head and it’s been fine, but double head might be nice if you have a lot of compressor capacity. I’m using a small compressor.


Heads up that on assembled units we install a 5th drain behind the baseplates that includes a 1" outlet, so flow is not an issue! We are working on a kit to add this 5th drain for people assembling themselves.



I was thinking the same thing with the half-gallon. Will probably start off with a single head for now.

Yes I was aware of that - for me it’s mostly about wanted to be able to see the tool cutting as I’m learning and also because I think cleanup will be a lot easier.