The Best Foam Cannon

Buying Guide

Anyone who has ever washed a car knows how much time you can save with a foam cannon. These sprayers are designed to do one job and one job only: Create a lot of suds and put them in a specific area. Whether you’re cleaning a car, van or some other large outdoor item, they’re a big step up from the old-school “sponge and a bucket of soap” technique.

When we talk about foam cannons, we’re generally referring to a tank with a nozzle that attaches onto a pressure washer. That tank holds a soapy solution, and when water gets pushed through it at a high volume, you end up with thick, clinging foam. There are also foam guns, and you won’t need a pressure washer for these. They can attach to a standard garden hose, and while they won’t produce the high-density foam of a cannon, they can be a good budget option for those who only clean their automobile once in awhile.

If you’re buying a foam cannon, the first thing you’ll need to check is whether it’s a good fit with your pressure washer. Heavy-duty pressure washers can pump out large quantities of liquid that some cheaper cannons aren’t equipped to handle. Check your cannon’s maximum capacity for two ratings: GPM (gallons per minute) and PSI (pounds per square inch). The former refers to the flow output and the latter is what kind of pressure you can expect.

In terms of the actual fitting that connects your cannon to the washer, they’re usually one size fits all. You will want to make sure that fit is secure, though. Your best bet is to go with a stainless steel connector that won’t bend or tarnish, though brass fittings can also work well. If you plan on using your pressure washer for more than just spraying foam, you may want to look for a quick-release connector. This should save you a little time on both assembly and disassembly.

If you’ve got a larger vehicle to wash, you’ll want a foam cannon with a lot of holding capacity. Most canisters hold roughly a liter, though you can go bigger. Just make sure you can maneuver with the extra weight.

Finally, buy with versatility in mind. Your pressure washer might be able spray several gallons per minute, but you won’t always need that much power. Choose a foam cannon with a nozzle that can regulate the flow based on what your foam mixture requires — and what your car needs.

So your car is begging for a wash and you’ve got your foam cannon ready to go. All you need now is a little fuel. The right foam mixture can make a ton of difference in what actually comes out of your cannon, no matter how powerful it is. If you’re on a budget, you can use regular dish soap in most machines. Foam formula generally doesn’t cost that much, and you can expect it to create a more consistent flow. Whichever one you use, you’ll need to dilute it with water first. Go with a 1:4 ratio of water to foam concentrate first, then add more concentrate if you want more thickness from there.

When you’re done with the wash, a little upkeep will prevent blockage. Rinse out your bottle thoroughly so there’s no foam solution left over. Spray some water through to clear any foam out of the nozzle and you’re ready for the next car wash.