Zero Fog mister

[Karl_T]

I’ve preferred a coolant mister over flood coolant on my machines without enclosures. The purchased units work well but they tend to put out a slight fog. If you spend 100s of hours in the shop you soon get sensitive to the smell. If you got $500 to spend a Henchforth Fog buster mister is the way to go. Being a cheap bastid, I looked up the patent and built my own in the late 90s. Built a better, generation 2 in 2002. Rather than re do all this older work, read these links:

original rec.crafts.metalworking thread 2002
https://groups.google.com/forum/?hl=en#!topic/rec.crafts.metalworking/zAzOhL8z3A4

short write up about my original zero fog mister
http://www.machinistblog.com/zero-fog-mister/

Other mister builds, nozzle info
http://www.cnczone.com/forums/general-metalwork-discussion/87439-cooling-hvlp-mist-producer.html

Great build thread
http://www.cnczone.com/forums/gener...nes/102934-built-fog-less-coolant-mister.html

 

[Karl_T]

OK, fast forward eleven years. The mister is still in use but has two weakness:
1) the 0.125" copper line work hardens from bending, gets caught in long swarf and gets ripped off. had to replace it three or four times.
2) sometimes you need more air blast to clear chips.

The pics are the gen 3 mister built last winter.

The tank is the same old one used for nearly 20 years now. To re fill it, remove plug insert funnel and pour in three gallons coolant.I use Hangsterfers S-500 mixed 20:1 with water. You can use Koolmist but doesn't provide the lubricity.

The next pic is the regulators and solenoids. I'm on CNC, thus the solenoids, use ball valves on a manual machine. The regulators are key, normally run about 20 psi on coolant tank and then turn air up just enough to break up coolant stream at nozzle. This will give a mist with large droplet size, no fog or odor at all. use the needle valve to adjust the amount of coolant. Normally just a crack open here unless deep hole drilling or milling, then open it up and nearly flood the work. On occasion, an air blast is needed to keep the chips clear, then just turn the air up to 100 and point the nozzle right near the work.

The last pic is the mister itself. An old indicator holder provides a way to quickly relocate the mister where needed. Got smart on this gen 3 combining block and built it on the lathe. One end fits the 3/8 copper, the other end is 1/8 NPT to fit Lok-Line, in the middle its necked down to about 0.100" for high air flow rate where it intersects the coolant coming in at right angle. The needle valve is just soldered in as is the large air line. There are prints of the gen 2 version in one of the above links.

I went to Lok-Line on the terminal end of the mister with the smallest nozzle they have, 1/16". Its NOT as good for atomization, but big enough to provide an air blast when needed. Makes it easy to direct the stream right where needed.

 

[JimDawson]

Yours is exactly like mine. Great minds think alike.:rofl:

Like yours, mine will run from a fine no-fog mist to a flood. I'm getting ready to do a write up on mine, I did this drawing a couple of days ago.

 

[catoctin]

I have been reading about and tearing apart several of the commercial units that are out there. Most work like siphon fed waste oil burners in that the siphon action and atomization takes place at the nozzle tip. The K___M____ unit feeds coolant through a tiny Tygon tube in the LocLine tube and allows compressed air flows around it. Coolant is fed to a brass fitting in the tip that has tiny tubes at both ends. One tube end is for the coolant line attachment and the other goes to the end of the main nozzle shroud. The brass fitting seats in the end of the LocLine tube and is square in the middle where it seats to allow compressed air to flow around it. The compressed air flows out the end of the nozzle and surrounds the other small tube at the end of the brass fitting. Basically, it works like the siphon fed waste oil burner nozzle designs found on the web.

I need to figure out how to make a small nozzle like the one described that can handle oil for synthetic coolant and standard coolant.

 

[Zamfir]

Thinking about building one of these. Might as well try it out! The Cool Mist and Noga Mist work great but the fog...

Question:
If a person could run the cool mist without the fog leaving the machine, would that not cool and lubricate better than the fog buster? I was going to throw a big fan with a hood that exhausted through a filter to remove the fog. That would be cheap and easy in my situation. But next to that, looks like folks really like the fog buster type applicator and a secondary air blast for chip removal?

 

[Karl_T]

I run heavy on the mist, way more than a regular mister, so I get nearly same cooling as flood.

Not mentioned above, I also have an air blast line with a switch and an M code. Use it on deep pocket to blow the chips out.

 

[Leonard]

Thanks for all the help Karl and Jim. Defineetly very descriptive options for me.