but keep in mind, higher pressure will wear more on
your nozzles, pipe, and pump, and you exceed the
ratings at your own risk.
The ball valve is in place to adjust the water
pressure going to the nucleation nozzle, and this
takes some playing around with to get it right. If the
water pressure’s too high, you’ll get a misty fog and
puny snow production. If it’s too low, you’ll get big
droplets that won’t freeze before reaching the bulk
spray, and you’ll be making very wet snow.
Compressor and Pressure Washer
The snow gun runs on 40psi–70psi from the air
compressor. It is highly recommended that you use
an oil-lubricated compressor; this will allow hours of
operation without any trouble. A good compressor
should be able to output 6cfm at 40psi.
A good pressure washer will feed about 2 gallons
per minute (gpm) at 450psi.
To make snow, you don’t necessarily need
temperatures below 32°F — you just need them
below freezing on the wet bulb temperature chart
( makezine.com/go/wetbulb), which takes into
account the relative humidity of your location. For
example, at 95% humidity you need temperatures
27°F or colder, but at 10% humidity you can start
making snow at just 39°F.
First, close the ball valve, so you don’t flood your
compressor. Turn on the water supply — but not
the pressure washer yet — and make sure water’s
coming out of the bulk nozzles. Make sure there’s
no ice in your pressure washer — ice could destroy
the unit or hurt someone — then turn on the pressure washer. Turn on the air compressor, letting the
pressure reach 40psi or more. Now start to open
the ball valve just a little, so you get a superfine mist
from the nucleation nozzle. Check the compressor
and make sure the air pressure is above 60psi.
You should be making snow!
To check your snow’s quality, put your coat sleeve
in front of the spray; the snow should bounce right
off. Check the gun periodically, making sure your
nucleation nozzle isn’t freezing up; if it is, open the
ball valve a bit more.
Elevating the gun gives the snow more time to
freeze before hitting the ground; you can use a
ladder or make a stand out of wood or PVC pipe.
Output and Precautions
So I’m sure you’re wondering, “How much snow
can I actually make with this thing?” The answer
depends on how much water you’re flowing, and this
depends on the water pressure and air pressure. The
more water you’re able to flow through the gun, the
more snow you’ll have piling up. Expect 2"– 5" per
hour, at 2gpm flow. Some advice to keep in mind:
1. Don’t shoot snow against the wind. You’ll get
freeze-ups. Go with the wind to make life easier.
2. Install a check valve between your compressor
and the snow gun; this will prevent flooding of
3. Air compressors are loud, so if you plan to make
snow overnight or in the early morning, be considerate of neighbors.
4. Your snow gun will hiss like a gas leak, so inform
your neighbors that it’s nothing to be afraid of.
5. Wear plenty of warm clothing when you’re making
snow, because it will be cold outside, and when
you’re working with water and metal pipe it will
seem a lot colder. Wear good waterproof gloves.
6. Don’t leave your hose outside with water in it, or
it will freeze and possibly split. Bring it inside. If it
does freeze, throw it in a bathtub of warm water.
7. Last but not least, have fun!
Special thanks to the contributors to snowguns.com,
where much of this information came from.
Steven Lemos is a mechanical engineering student at CSU
Chico, and has an infatuation with the odd and bizarre. A
former intern at MAKE, he still shares his interests with us.
Mixing Epoxy Without Bubbles To avoid whipping in a lot of air bubbles, use a bent palette knife when you mix up a small batch of epoxy. You can stir up down and around thoroughly without letting the bent section break the surface, so you’ll be able to get a nice clear bubble-free mix. —Frank Ford, frets.com/homeshoptech Find more tools-n-tips at makezine.com/tnt.