Coolant Misting System
Last updated on Tuesday, September 19, 2023 04:00:29 PM Mountain US Time Zone


Nozzle, Air Supply, Valves, Reservoirs

This is a Kool Mist spray coolant system (manual).
I use it mainly for air cooling & chip removal.

A momentary, solenoid-activated liquid control valve
will allow very short deliveries of liquid lubricant.

The solenoid can also be controlled via g-code
using Mach3 & its
relay box in a CNC application.


Lightly misting an aluminum surface with a
water-soluable coolant
while fly-cutting. Rusting
due to the coolant's water content posed no problems.

he nozzle moves with the cutter.
The mill's paint was too thick & the magnet
too weak to allow a strong attachment. 

The liquid/air mix valve is attached to a 1/2" steel plate
that has two 10-32 cap-head screws threaded into the mill.

Coolant/air mixture valve mounted on
steel base with aluminum spacer block.

A counterbored 10-32 cap-head bolt fastens
the unit from the plate's back.

Brass spray nozzle is adjustable. A thin air
line is inside the main, repositionable tube.

Coolant & air mixed at the nozzle's tip.

Air Supply

Shop air supply compressor (manual).

Also see the Hand Tools Section.


Sub-plate mounted onto the left-rear of the
mill stand with three sheet metal screws.

The plate has 10-32 bolt taps for the L-bracket.

L-bracket milled to hold the air valves.
The channel is 5/8" to trap the connector nut.

Note the 6-32 set screws
(above) were
changed to 10-32 (below) for a better grip.

Installed 1/4" NPT (6.4 mm) mini-ball valves
to control both the air & coolant supplies.  

The air valve & the spring-loaded quick
connect/disconnect mount through the bracket.

The gap between these particular connectors
is about 0.08". The system works well with

higher (70-90 psi) pressures.
The two valves
allow good control over both air & coolant.
Note these are tapered threads so use thread-
sealing teflon (paste prefered) & be careful
to not overtighten.


Coolant tank made from a 1 gal. gas can
which is low cost & chemical resistant.

The coolant pick-up tube end has the Kool
Mist particulate filter/anti-siphon valve.

The metal lid has a 1/16" hole to let in air.
The coolant is Kool Mist 77 diluted 1:20 distilled H

Kool Mist SS coolant reservoir
with mixing & air supply valves.

Nozzle, Air Supply, Valves, Reservoirs