You may have heard the terms ‘foam gun’ or ‘foam cannon’…two devices that can help you apply soap or foam to your vehicle much easier and quicker. But what makes these devices so special? What exactly is foam?
In this post, I’ll cover the basics so you can decide which is right for you, plus a few recommendations if you’re considering one or the other.
To understand foam guns and cannons, it helps to first understand what car foam actually does.
Snow foam vs. car shampoo
Snow foam is a type of product specifically designed for foam guns and cannons. It is technically a pre-wash agent designed to trap and remove heavy dirt when rinsed off…not a replacement for car shampoo. Car shampoos contain wax and other protective substances that are designed to protect the clear coat when a wash mitt is used.
Most people just use shampoo and a bucket which is perfectly fine, but using foam is a smart pre-wash technique.
Let’s start with the basics of foam guns and cannons. Many people tend to use these terms interchangeably, but they are in fact different.
What is a foam gun?
A foam gun is a simple device that includes a sprayer, a quick-release nozzle, and a tank to add either foam or soap. Unlike a foam cannon, a foam gun can apply foam to a vehicle without the need for a power washer, which makes them ideal for most people.
Most foam guns allow you to regulate the amount of foam produced. I have a foam gun with a circular dial (with settings 0-5) that can be switched to the ‘0’ or off setting which dispenses only water for rinsing (without disconnecting the device).
If you want to apply foam without a power washer or a bucket, a foam gun is good choice.
Foam guns vs foam cannons
While both foam guns and foam cannons obviously apply foam, a foam cannon produces a thicker shaving-cream-like foam since it’s used with a pressure washer.
Foam guns cost around $20-$50 dollars depending on the build quality, while foam cannons start in the $30 to $70 range for base models. Premium models will include brass fittings, while cheaper foam guns/cannons will be all plastic.
What is a foam cannon?
A foam cannon is very similar to a foam gun, but can handle high pressure.
Most foam cannons consist of a bottle for adding foam, a foam spray regulator, and a quick disconnect for your pressure washer.
Foam cannons are often used by detailers who wash large trucks and SUVs as a first step. They save a ton of time!
Why use foam to wash a vehicle?
Foam helps trap more dirt than soap alone, so it’s good to apply prior to hand washing. It’s easier to scratch the clear coat of a very dirty vehicle if you apply standard car shampoo by hand.
Most people simply fill their bucket with car shampoo, spray down their vehicle, and then use a circular motion with a mitt. This can lead to swirl marks unless the vehicle isn’t very dirty.
Swirl marks are basically tiny circular scratches that are produced when you rub a wash mitt over a really dirty surface. When you break it down, this dirt is really just made up of tiny jagged particles (rocks, and other debris).
Does foam really remove dirt from a vehicle without rinsing?
Yes and no. Foam helps remove some top layers of dirt on a vehicle when rinsed off, even if you don’t use a sponge or mitt.
However, without making contact with the vehicle with a wash mitt, foam won’t release the static bond that causes some dirt to cling to a vehicle. Foam has its place..but it’s not the perfect touch-free solution some think it is.
A few of the best foam guns to consider
I’ve seen a ton of foam guns over the years, but a couple stand out. Most work the same, but if you really want a quality foam gun, prioritize build quality. Things like brass fittings and user reviews matter..don’t you just hate when plastic breaks?
Adams Premium Foam Gun
What I like
Top-notch build quality, with a metering tip instead of a dial for regulating foam
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Adam’s makes pretty good detailing products, and their foam gun is no exception. There are a ton of foam guns out there, but this one is made well, which is why I recommend it.
This unit uses a metering tip to control the amount of foam produced, unlike some that use dials. I bought a cheap one a while back that uses a dial, and they absolutely kill your fingers trying to adjust. Just something to consider.
A few top foam cannons to consider
There are a bunch of different foam cannons available. Most are built similarly, but I just think the branded stuff (Chemical Guys, Adams, and others) is the way to go.
If you need replacement parts or add-ons, a no-name company might not offer these products.
Adam’s Foam Cannon with Snub Nose Nozzle
What I like
This one has lots of adjustments, is well-made, and performs much better than cheaper foam cannons.
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This is one of the nicest foam cannons I’ve found that also comes with a ‘snub nose nozzle’ which sort of resembles a gas pump. I’ve you’ve ever used a foam cannon at a car wash, this is the type of trigger mechanism used.
It makes applying foam a little more convenient by adding a trigger attached to the unit (instead of using a longer pressure washer lance).
MTM Hydro Professional Foam Cannon
What I like
High build quality, sprays up to 20 feet..and can also be used for other home applications
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Another cannon on the higher-end side is this model by MTM Hydro. It’s actually one of the best at regulating the spray pattern and has a few more adjustments. This type of cannon performs best with gas-powered pressure washers.
This model has adjustable air intakes and fan blades, can spray foam up to 20 feet, and is ideal for RVs or large vehicles.
Fasmov Snow Foam Cannon
What I like
It’s affordable for beginners new to foam cannons
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Last but not least this one (or similar) I would recommend for beginners or hobbyists since it is so affordable. This one was around 20 bucks the last time I checked, has brass attachments, and is really all you need if you’ve never used a foam cannon before.
However, if you deal with high-end clients, the more expensive cannons may actually be worth the investment if you are an advanced detailer with the money to spare.
Snow foam brands to consider
Getting a foam gun or cannon? Don’t forget about snow foam. Since foam cannons tend to use a lot of snow foam concentrate, you’ll commonly see snow foam sold in large containers. However, if you’re new to foam and thinking about a basic foam gun/cannon, pick up a small snow foam product to test out like this one:
Chemical Guys Blueberry Snow Foam
What I like
A good brand for beginners and is available with optional add-ons
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If you have a larger vehicle, I recommend you pick up one of these large containers. They will run you a bit more but last a lot longer.
- Chemical Guys HoneyDew Snow Foam – 1 Gallon
- Adams Ultra Foam Shampoo – 1 Gallon
- McKee’s 37 Foam Formula- 1 Gallon
If you’re new to foam cannons or guns, you can find kits that usually include snow foam, the canister and attachments, and sometimes towels and extras.
How to produce thick foam for washing your vehicle: 5 factors
There are a few tricks to producing that thick, shaving cream-like foam you may have seen in videos. One of the most important is obviously the device type since cannons produce thicker foam than guns due to pressure. Here are a few other important factors:
1. Your pressure washer
Gas pressure washers are going to give you the most power right off the bat, which is important when producing foam. Usually, you need around 2.0 gallons per minute at a minimum which some electric pressure washers struggle to achieve. Just make sure you check the ratings on your pressure washer.
2. Water-to-soap ratio
If you are having trouble with high-quality soap not producing thick foam, make sure you dilute it according to recommendations. 20% of the container filled with soap, and the rest with water is pretty standard.
2. Orifice size
Foam cannons come with these orifices (usually 1.1-1.25 mm) that can really be the difference maker when it comes to how much foam is released. These tiny little brass fittings can be purchased separately. Check out this YouTube video for a better explanation.
You also want to remove the tank from these cannons and flush the lines with clean water periodically to prevent corrosion.
4. Type of foam
Some snow foam brands produce more than others…typically anything with a ‘snow foam’ will be pretty good. Just stay away from regular soap.
5. Warm water
Try mixing in a bit of warm water in your snow foam canister to produce more foam. Warm water has less surface tension than cold water, which makes it easier to produce foam.
Ready to start using foam? Here’s what you need
Foam is pretty cool, and if you are thinking about getting a foam cannon, you’ll need a basic pressure washer. If you’re considering one, here are 5 electric pressure washers I recently wrote about fit the bill for beginners.
Yes, gas-pressure washers do tend to generate thicker foam…but I think they’re a bit overkill for the average vehicle.
Buying tip: Many ‘private label’ foam guns/cannons are nothing special. Often times these are just very generic devices with fancy colors and logos, but $50 or $60 more. The same goes for soaps for the most part. Always be sure to read reviews.
New to detailing? Check out my free eBook, 25 Essential Auto Detailing Products for Beginners for more products that can improve your detailing ability.
This post was updated on January 28, 2022
