Guide to Foam Cannons

Guide to Foam Cannons

Foam cannons cover your car in thick suds and cut down the time required to wash your car.

The added lubrication helps reduce the chance of getting swirl marks in your paint from washing.

This guide outlines the proper procedure of using a foam and also maintaining it.

Following this set of instructions will help ensure you get tons of suds and your foam cannon lasts a long time.

Equipment you will need:

  • A Quality Foam Cannon
  • Short Pressure Washer Gun
  • High Sudsing Car Soap
  • Extension Wand For Rinsing
  • Pressure Washer (recommended 1.7GPM for thick suds)

Breakdown of Equipment:

Foam Cannon: 

Choose a high quality foam cannon that can produce thick suds with both electric and gas pressure washers.

Make sure the bottle is not opaque so that you can see the amount of soap solution that remains.

The bottle should also have volume measurements on the side so that you can dilute the soap solution properly. 

Short Washer Gun: 

Attaching a foam cannon to the end of your pressure washer gun can make it very hard to maneuver.

It is also challenging to attach a foam cannon to a longer washer gun.

These short guns make it easy to attach foam cannons, and to spray foam on the roofs of vehicles.

These truly make a huge difference.


Extension Wand: 

These wands are a must-have for washing cars.

These are essential for using alongside a short pressure washer gun.

They make it very easy to rinse vehicles after washing, and the angled wand helps in washing the roofs of vehicles.

Car Soap: 

This is perhaps the trickiest variable in the equation for getting good foam.

Every car soap is made a bit differently and therefore has to be diluted differently.

Choose a car soap that is concentrated, pH neutral and high sudsing.

As a general starting point, try diluting 200mL (6.5oz) with 800mL (27oz) of warm tap water.

We're currently developing our own soap, follow our instagram for updates if you're interested!

Blueberry Blast Soap in action with a gas pressure washer rated at 2.1 GPM. 

How much soap to use?

The most important factor for thick foam is the type and amount of soap you use.

There are a wide variety of car soaps on the market which you can use with your foam cannon.

You should only use car soap (obviously). To get thick foam from your foam cannon, you must choose a car soap which is high sudsing and highly concentrated.

Diluted car soaps will result in a watery foam and not the thick ‘shaving cream’ consistency that everyone loves!

Try adding approximately 6-7 oz (200mL) to the bottle and fill the rest with warm water.

If your foam cannon is still shooting watery foam, try adding more soap or using a more concentrated car soap.

Ensure the soap has fully dissolved in the bottle, and not stuck at the bottom.

Experiment with your soap and foam cannon to determine the proper ratio of warm water to car soap.  

Which Pressure Washer?

The pressure washer you use is also very important.

Generally speaking, gas powered pressure washers offer a higher flow rate and pressure output, which results in better foam.

Check the GPM(gallons per minute) value on your pressure washer.

Electric pressure washers can also be used, but we would recommend that it at least have a GPM of 1.75 and a 1900 PSI rating.

Our Choice: The New King! 

Active VE52 | 1800 PSI | 2.0 GPM | 13 Amp | Electric Pressure Washer

The Active VE52 is the new king of the budget friendly pressure washers.

It outputs a cool 2.0 GPM on a standard 15amp household outlet.

We've personally tested the Active VE52 and can vouch that it is perfect for the at-home detailer. 

It's quiet, powerful and can be wall-mounted on a shelf if desired. 

Lot's of pressure washers exaggerate their stats, but cannot match them in real life. 

Active VE52 is the real deal.  

Is my pressure washer too weak?

The foam cannon will still work if you are using a less powerful pressure washer. 

Some Ryobi, or Greenworks' models which are rated for around 1.2 GPM and 1600 Psi. However, you should expect the foam to be more runny.

We recommend that you start with whatever pressure washer you have.

Once you feel that an upgrade it warranted, feel free to buy the correct pressure washer for your application.

First use tips and instructions:

Ensure your foam cannon is correctly dialed by adjusting the foam density knob, and the fan angle nozzle.

The pickup tube should be cut at an angle.

This prevents the tube from being blocked when inside the bottle.

Oddly enough this simple problem can result in very watery foam!

Once you have ensured these steps, pour 6-7 ounces [200 mL], of car soap to your bottle and fill the rest with warm water.

Shake the bottle and mix well. Connect to your pressure washer and foam away!

The Tip Most People Miss:  


It it is very important to properly maintain your foam cannon and always wash and dry it after use.

After using your foam cannon, refill the bottle with tap water and run the water through the foam cannon. 

You can also remove the nozzle and run it under tap water.

Leftover soap within the foam cannon nozzle will cause buildup within the internal filter and cause watery foam.

You should also remove the nozzle and run it under some tap water, and then dry it.

Following this procedure after every use will ensure your foam cannon lasts a long time.

No Pressure Washer? 

If you do not have a pressure washer, you can use a garden hose foam gun.

Even with just a garden hose, you can still produce decent suds to improve your washing process. 

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