Why and How to Use a Foam Cannon

Jared Geoff

Updated on:

man spraying a car with water

Many car detailing enthusiasts and those of you starting to take an interest in detailing might get overwhelmed at first. With so many great and not so great products out there, you wonder if you really need all that. One item that people are always curious about is the foam cannon a.k.a. foam lance, foam gun, or foamer. Why use a foam cannon? Should a DIY foam cannon become a regular part of your car washing routine? Well, car detailing pros and probably all foam cannon owners can give you a million reasons why you simply must use one! Yeah, we might be exaggerating a bit, we just get really https://www.metziahs.com/xanax/ excited when we talk about car detailing. However, we do hope that our enthusiasm will rub off on you as we share with you why and how to use a foam cannon. Ready for more? Let the foam party begin!

What is a foam cannon?

A foam cannon or snow foam lance is a gadget, attachment, or accessory used for prewashing cars and vehicles. The main parts of a foam cannon are:

  • body which can be made of different materials depending on the producer (brass is very common)
  • quick connect ¼” for connecting the foam cannon to an electric power washer
  • nozzle typically with an adjustable spray pattern; there are two blades that determine how wide the foam spread is 
  • knob or aerator for adjusting the air intake
  • bottle (usually plastic) where you mix water and the foam liquid; approx. 1l or 33 fl oz.
  • tube for picking up the water-snow foam mixture.

This practical and handy washing attachment is used with a power washer because high pressure is needed for creating thick foam. Other elements play into the foam quality and those are: 

  • water hardness level – the softer the water, the better the foam
  • snow foam liquid
  • pressure washer’s capacities – PSI (Pounds per Square Inch) and GPM (Gallons Per Minute). Same principle – the higher, the better.

Why use a foam cannon?

This mighty little helper is essential for a detailed washing of your vehicle. What’s more, car detailers use it in the prewashing step of the detailing process. The foam you spread over the vehicle serves to thoroughly lubricate the vehicle surface. Once well lubricated, the foam removes any contaminants which simply drip down with the foam. 

This is particularly important because in this way you minimize or completely eliminate the chances of creating swirls and scratches on your coat of paint. If you skip this step and start with the contact wash immediately, these contaminants cling to the sponge you use for washing. Moreover, while you make circular hand movements, these dirt particles can create microdamage. These visible swirls can have a serious impact on the coat of paint in the long-term. Plus, the car loses its impeccable clean surface shine, and we don’t want that to happen now, do we? For those of you wondering which one to choose, you can check out our best foam cannon review guide for more information.


man washing a car in front of the garage

How to use a foam cannon?

First of all, using a foam cannon is pretty straightforward. It all starts with making the right mixture of foam liquid or snow foam and water. The product-water ratio differs from one car detailing product manufacturer to another. Commonly, the producers recommend the 1:8 snow foam to water ratio or, for example, 2 fl oz. of snow foam and 16 fl oz. of water. The best thing to do is to first follow the producer’s instructions. However, feel free to experiment with the ratio and different products until you find the one which makes the thickest and richest foam. 

Once you make the dilution, you connect the foam cannon to the pressure washer. Adjust the nozzle and air intake and start creating a foam blanket over your vehicle by evenly applying it from top to bottom. After the foam dwells for a few moments on the surface and tires, it’s time to wash it down with the pressure washer. Now all the contaminants are removed from the surface together with the foam and you can continue with washing your precious car. Sweet!

Final words

To sum things up, foam cannons are highly useful washing accessories used for prewashing your vehicle. This is particularly important for cleaning the car surface thoroughly before contact washing. Also, a foam cannon wash is essential before applying other detailing products such as iron or rubber remover sprays or ceramic coating. This is one of the most important reasons why detailers use a foam cannon. Aside from all the practical reasons, washing your vehicle with a foam cannon is therapeutic. There’s something soothing in watching and listening to foam dripping down the surface and tires of your vehicle. Maybe we’re just crazy about car detailing. Or maybe foam cannons are just highly effective and fun, period.