Foam Cannons for Pressure Washers – A Complete Guide

What are Foam Cannons

Foam cannons are specialty attachments that can be used with pressure washers to create significant volumes of foam.  There are also Foam Cannon attachments designed to be used with a regular hose, though they create less foam compared to a pressure washer attachment.

Why Use a Foam Cannon

• Soap Suds help encapsulate and remove dirt and Foam Cannons create greater volumes of soap – the greater the volume of suds and soap you have when washing a car or similar surface, the cleaner the surface will get.  A Foam cannon generates significantly more suds then a washing mitt or a bucket with soap in it.  The higher volume of suds and soap will provide a cleaner surface when you’re finished. Additionally, if you’re cleaning a car with a lot of dirt on it, a foam cannon is more efficient than a bucket of soap because a bucket of soap will begin to collect dirt as you use the soap with a brush, sponge, or mitt no matter how hard you try the water always gets somewhat cross contaminated.
• You can clean a car faster compared to using a mitt or bucket alone – The soapier you get a surface the cleaner it will get. The foam cannon creates high volumes of foam quickly and efficiently. This makes cleaning a car fast and easy compared to a bucket or wash mitt.
• Reduced chance of scratching the car – By Using a foam cannon you avoid or reduce running a mitt or sponge over your car, which can eliminate the potential scratches that a mitt or sponge can cause.

What is Needed to Use a Foam Cannon

Using a foam cannon requires two things; a pressure washer with sufficient pressure and volume to run the cannon and chemicals that are designed to be used with a foam cannon.  We will go into both in detail.

• A pressure washer with sufficient volume and pressure – Foam cannons generally require a minimum of 1100 PSI and 1.5 GPM output, though higher quality and performance foam cannons will usually require 1500 PSI minimum with 2 GPM output, typically the maximum PSI will be around 5000 PSI and 5 GPM but this can vary depending on the quality of the foam cannon.
• Foaming solution – in addition to having a properly rated pressure washer, foam solutions that are designed to properly clean the vehicle are also needed. Soaps designed for use in Foam Cannons are best as they will generate greater suds volume when used with your pressure washer. We offer this solution that can be a great option for foaming.
• A Foam Cannon – This is pretty obvious, a foaming nozzle or wand attachment is needed.

What kind of Foam Cannon options are there?

There are a few different standard foam cannon attachments that can be used with a pressure washer to enhance car surface cleaning as well as different quality levels.

Consumer Grade – These foam cannons will get the job done.  Though the components are not always as high quality, they may use brass rather than stainless fittings, the bottles may not have a threaded seal and gasket, and there are generally similar design changes to reduce costs.  These are great for the weekend warrior car cleaning and occasional use.  They are also affordable, usually around $40 for a setup.  The downside to these foam cannons is that they often  leak around seals and stop working as well over time.

Professional Grade – Unlike a consumer Grade Foam cannon, a professional grade foam cannon will use stainless fittings, have a more precise flow control valve (for greater control of foaming), and have better components for the plastic bottles. These usually go for around $80-$100.

How to use a Foam Cannon

Once you have settled on the foam cannon to use, the next step is to setup your foam cannon and get to work cleaning.

Before using the foam cannon, it is advisable to wash the car with water first, this will help remove any loose dirt and make your foam cleaning more effective.

Most foam cannons use a simple quick connect to attach to a washer’s trigger gun or extension.  You need to connect the foam cannon to your pressure washer gun, generally having a short nosed trigger gun for the washer included will make it easy to foam your car.  Additionally, it is vital to fill the foam cannon container with the foam cannon cleaning solution of choice and ideally warm water, ensuring the cleaning solution is properly mixed (some require a dilution while others can be used directly from the original bottle). 

After you have connected the foam cannon, and filled the foam reservoir, it’s time to fire up the power washer.

From there you can use the foam cannon and make adjustments to the foam output, using the volume adjustment. This is usually a knob on top of the foam cannon that dials in the foam volume.  The fan pattern size can also be controlled by twisting the front of the foam cannon.

Troubleshooting Problems with Your Foam Cannon

If you find your foam cannon is producing runny foam try checking your soap to water mixture; using too much water will produce runny foam.  You can also check the pressure and GPM output of your washer, generally, having at least 2000 PSI provides greater foaming compared to a low pressure 1000 PSI washer. Finally, consider using warm water to better mix up the soap and water.

After you have washed

After you foam your vehicle down and clean it, it is advisable to run clean water through your foam cannon to properly remove any residual foam. 

So there you have it, a complete summary of everything related to foam cannons; from what they are, to why use one, and to how to use a foam cannon. If you’re interested in a foam cannon for your project, you can visit our collection here