Introduction: External Mix Snowmaker (aka Snowgun)

A word of warning, this is my first Instructable, but hopefully not my last.  Snowmaking is a fun activity that can involve the whole family.  Using a small household pressure washer and a household air compressor (that produces at least 5CFM@60psi) you can make snow.  The other parts required are listed below. 

The choice of nozzle is very important for external mix snowguns.  Make Snow dot Net offers a package including all of the nozzles in this project for $60 bucks, all are stainless steel or nickel plated brass Here's the kit:  
Brass nozzles that have not been plated will wear quickly, and should be avoided.  

DISCLAIMER: Dealing with high pressure water and air is dangerous, never point water towards people or pets, always use fittings rated for the pressures used. Wear eye and hearing protecton at all times. is not responsible for any damages or injury.

1 MSM-X250 Nozzle (available at )
2 MSM 0204 Nozzles (available at
1 MSM – X2A Nozzle (available at www.MakeSnow.Net)
1 22mm to ¼”NPT fitting (available at www.MakeSnow.Net)
2 ¼” NPT Street Elbow – 90 degrees (rated to at least 2000psi)
2 ¼” NPT Female T- fittings (rated to at least 2000psi)
2 ¼” NPT Female Elbow – 90 degrees (rated to at least 2000psi)
3 ¼” X 1” close nipple fittings (rated to at least 2000psi)
1 ¼” NPT Female to 1/8” NPT Male Bushing (rated to at lease 2000psi)
1 Roll of Teflon Tape
1 ¼”NPT female thread Compressed Air Quick Connect
1 Piece of Metal to mount the snowgun on 

Step 1: Assemble the Water Plumbing

Connect the parts together as follows. Always put at least three layers of Teflon tape on the male
threads before attaching the fittings together, including the threads on the nozzles. Attach the Street Elbow to the end of one T-Fitting.

Step 2: Attaching the T-Fitting...

 Take a second T-Fitting and attach the 22mm to ¼” NPT Fitting in the perpendicular outlet of
the T-Fitting (that is, if you were to place the T-fitting so it looked like a T, you would be
attaching the 22mm to ¼” NPT Fitting to the bottom 

Step 3: Attach Steps 1 and 2 Together

Attach the parts from steps 1 and 2 together with a close nipple.

Step 4:

On the bottom T fitting connect a ¼” X 1” close nipple and a ¼” NPT Female elbow

Step 5: Add the Upper Nozzles

On the open threads from the elbow in step 5, attach a second ¼” X 1” close nipple and the
second ¼” NPT Female elbow. Attach the two MSM0204 nozzles to the exposed threads at the top of the snowgun.

Step 6: Setting Up the Air Nozzle

Take the air quick connect fitting, ¼” Street elbow and attach them together

Step 7: The Alignment - Will Make It or Break It

Take your mounting bracket and correctly set it up so that the MSM-X250’s water mist will be
intersected as closely as possible by the air from the MSM-X2A’s stream. This is the most
important part of building an external mix snowgun, the nozzles must be as close to perfectly
aligned as possible or the snowgun will not make snow. We are happy to answer questions
about building snowguns, however because of the volume of questions we received about the
alignment of external snowguns in the past we are unable to provide answers on how best to
align these nozzles. offers pre-made external mix snowguns if you question your ability to
attain the correct alignment.

Step 8: Starting to Make Snow and Shutting It Down.

To start up your combo gun follow these steps, complete each step before you move on to the next
1) Check the wet bulb temperature so it is less than -1C or 30F (or the dry bulb temperature is
below -2C or 28F)
2) Lay out your hoses where they will be during the run
3) Connect the water hose to the faucet.
4) Turn on the air compressor
5) Attach the end of the water hose to the snowgun
6) Attach the air hose to the snowgun
7) Connect the air hose to the air compressor
8) Turn on the water at the faucet
9) Turn on the pressure washer.
10) Make Snow!

Shut Down Procedure
To shut down your MSX-250 follow these steps.
1) Turn off pressure washer
2) Turn off the water and disconnect the water hose at the faucet.
3) Turn off air compressor
4) Disconnect gun from hoses
5) Drain Hoses
6) Store hoses, pressure washer, and snowgun in an area which will not allow them to freeze

If you liked this instructable, check out the easier Internal Mix Snowgun Guide