Foam Cannon Soap Ratio (+ Other FAQs)

Image Credit: AdamChandler86 via Flickr

Image Credit: AdamChandler86 via Flickr

Foam Cannon Soap Ratio (+ Other FAQs)


There are lots of questions I get asked bout foam cannons. The most frequent one is the soap dilution ratio. The best foam cannon soap ratio varies depending on personal preference for thick foam as much as the concentration of your car wash soap and the equipment you’re using. If you’re new to operating a foam cannon or foam gun, start with a 10:1 ratio and adjust from there as needed.

Keep reading to learn more about ensuring you get the thickest suds from your foam cannon.

Foam Cannon Soap Ratio

A typical ratio of soap to water in a foam cannon reservoir is 10 to 1. The ratio can vary quite a bit depending on how concentrated the snow foam shampoo being used is and other variables such as pressure washer gallons per minute, pressure, and foam cannon nozzle design. Usually, your foam cannon soap manufacturer will include a suggested soap ratio for use with a foam cannon or foam gun.

Do you add water to a foam cannon?

You’ll want to add 10 parts water to 1 part car wash shampoo to the cannon canister. Undiluted soap will not flow well up the intake hose. It also won’t produce the best thick foam and will waste a lot of product.

Once you’ve added the soap and water to the foam cannon bottle, you will want to mix it thoroughly. You can shake the bottle a bit to mix the soap in evenly. Please don’t shake it too aggressively, or you end up causing the soap to begin foaming in the bottle. You want to shake it enough to get the soap and water mixture evenly combined.

How do I make my foam cannon more foamy?

Here are 6 things to consider if you aren’t able to produce as thick of foam as you would like from your foam cannon:

  1. Ensure your foam cannon soap ratio is 10:1 water to soap.
  2. Ensure your pressure washer can flow at least 1.4 GPM but preferably 2 GPM.
  3. Ensure your nozzle orifice is properly matched to your pressure washer’s GPM.
  4. Ensure your nozzle orifice is properly cleaned.
  5. Ensure you’re using a high-quality foam cannon.
  6. Ensure you’re using a car wash shampoo that is designed to work with a foam cannon.

Will any soap work in a foam cannon?

Most soaps will produce some suds by their nature, but not all will produce thick foam.

The best choice for a foam cannon is to use a car wash shampoo designed explicitly in foam guns and foam cannons and at the proper soap ratio. A car wash shampoo designed for use in foam cannons and mixed to the appropriate ratio will produce the thickest and most protective foam to maximize cleaning power and reduce the chances of causing fine swirls and scratches in your clear coat.

Is a foam cannon better than hand washing?

The answer depends on your primary goal. Using the touchless method with a foam cannon will all but eliminate the chances of creating fine swirls and scratches in your finish while washing. Hand washing using the two bucket method will more thoroughly clean the surface of your clear coat but runs a greater risk of dragging abrasive grit across the surface of your paintwork.

Often a foam cannon is used in combination with hand washing. Using a foam cannon to first loosen and remove a large amount of the road grime from the surface of your car or truck reduces the chance of creating fine swirls and scratches in your finish when you follow it up with a more effective hand wash. Also, applying a thick layer of foam onto your paint provides a thick layer of lubrication that will help keep dirt and debris from creating scratches as you hand wash the surface.

Is it worth using snow foam?

Snow foam has some distinct advantages over other alternatives. Car shampoos that produce thick foam are usually designed to be pH neutral. Thick, pH-neutral car soap helps preserve any wax, paint sealant, or ceramic coating applied to the surface while still creating a lot of good cleaning power.

For instance, harsher soaps, like dishwashing soap, can accelerate the breakdown of your protective paint coatings.
The thick foam also creates a good lubrication effect that helps prevent fine swirls and scratches in your clear coat. You can also use a thick snow foam to cover the surface of your vehicle and allow the suds to sit and break down the bond the dirt and road grime has with your paintwork.

Foam cannon not pulling soap?

The 2 main reasons for a foam cannon not pulling soap out of the bottle are:

  1. Poor soap dilution ration: Little or no water was added to the foam cannon bottle with the soap
  2. Foam cannon bottle pickup placement: The end of the pickup hose inside the bottle of some foam cannons can suck to the bottom or side of the bottle and prevent flow

How long do you leave snow foam on a car or truck?

It’s best to leave snow foam on your finish for 10 minutes or so. Allowing snow foam to dwell will allow it the time it needs to break down the bonds the dirt and grit have with your paintwork.

Washing your vehicle with the touchless method can only do just so much. If your vehicle is filthy, you will need to follow the foam with hand washing, or you will need to repeat the layer of snow foam and allow it to again sit for approximately 10 minutes.

Can you use snow foam without a pressure washer?

A pressure washer isn’t required to use snow foam, but it is the most effective method of achieving the thickest foam layer.

If you’d like to mimic the snow foam generation as closely as possible without having to use a pressure washer, you can use a foam gun that connects to a garden hose. A foam gun isn’t as powerful as a foam cannon and won’t produce the same amount and quality of thick protective suds, but it will be a reasonable alternative.

You can also apply car shampoo directly to your wash mitt or wash bucket if you’re hand-washing without a foam cannon or gun. Applying shampoo directly to your wash mitt is a great way of ensuring that you have ample car wash soap between your wash mitt and clear coat to maximize lubrication and cleaning power. It will also help conserve soap and better ensure consistency across the vehicle.

What is the difference between a foam gun and foam cannon?

A foam cannon is an attachment for a pressure washer that mixes car wash shampoo with the water and air to let the soap foam up. The concentration of the soap, gallons per minute (GPM) of the pressure washer, foam cannon design, and adjustments available via a knob on the foam cannon and pressure washer all factor into how well your setup will produce thick foam.

A foam gun is an attachment for a garden hose that works similarly to a foam cannon. Due to the significantly lower pressure, you will not achieve the same quality of thick foam. It will, however, allow you to spray a decent foamy coating across the surface of your car or truck and increase the quality of lubrication between your wash mitt and your clear coat.

Do you hand wash after foam cannon?

It isn’t necessary if your car or truck isn’t filthy and you’re trying to use the touchless method. For dirtier vehicles, hand washing after thoroughly coating your finish with a thick layer of suds from a foam cannon is the ideal way to hand wash your automobile.

Does GPM matter for a foam cannon?

Gallons per minute are very important to get the most out of your foam cannon. Most foam cannons work best with a minimum of 2 GPM. Gallons per minute aren’t an issue for gas-powered pressure washers typically, but electric pressure washers often don’t quite meet this minimum. Often you’ll see a minimum of 1.4 GPM for a foam cannon, but this won’t be ideal. It will work, but 2 GPM is much preferred.

While electric pressure washers are ideal for many reasons, you need to make sure you’re buying one that has as high of a GPM as you can afford. I highly recommend checking out the very reasonably priced Active VE52.


What does snow foam do?

Snow foam serves two primary purposes:

  1. Break down the bond that road grime has with your paintwork
  2. Provide lubrication to reduce the chances of fine swirls and scratches

Car wash shampoos are designed to be hard on dirt but easy on wax and paint sealants. To do this, they are made to be pH neutral. By creating a thick foam layer on top of your finish, snow foam has a more ample opportunity to break down the bond dirt and grime with your clear coat.

Also, a thick layer of foam provides excellent lubrication between your wash mitt and your finish. It helps suspend dirt particles up and away from the vehicle surface better as well.

Is a foam cannon better than hand washing?

Foam cannons are great for doing a touchless car wash and making it easier and safer on your finish to do a hand wash. Touchless washes with a foam cannon are better than hand washing at preventing fine swirls and scratches, but hand washing is better at removing stubborn road grime from your finish.

Foam cannons make hand washing more effortless and safer by allowing you to pressure wash off the majority of the loose grit without physically touching the vehicle. It also creates a thick foam layer that helps lubricate the surface to reduce the chances of fine swirls and scratches during hand washing.

Should you rinse your car before snow foam?

You should always rinse your vehicle before applying snow foam or hand washing. A good pressure wash rinse will remove the majority of loose dirt and grime, which will increase the opportunity for snow foam to work on more stuck-on dirt, and it will reduce the chances of fine swirls and scratches if you hand wash after coating your car or truck with snow foam.

Do you use a sponge with snow foam?

Sponges aren’t the best choice for washing a vehicle since they don’t provide as much protection from swirls and scratches as microfiber. A microfiber wash mitt is the best choice when hand washing.

If you prefer sponges, a natural sponge versus synthetic is the safer route

Can I use wash and wax in a foam cannon?

A wash and wax is ideal to use with a foam cannon. The wax used in a wash and wax shampoo isn’t particularly thick, so it has no detrimental effect flowing through the cannon’s nozzle.

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