Foaming your car won’t much good if you use the wrong soap.
Car shampoos are designed for manual application, not cannons. And just about any cleaning agent – even car wash soap – won’t create enough of the thick suds that make foam cannon soap so effective as a pre-wash.
The Foam Cannon Soaps
Let's take a look at some of the best options available
1. Adam's Ultra Foam Shampoo
Here’s a good example of the difference between car shampoos and snow foam soap: this manufacturer makes its foam cannon soap with four times the cleanser concentration of its regular car shampoo. Adam’s is one of the many foams which contain a lubricating chemical in its solution, designed to avoid paint scratches when it’s rinsed off; it also includes a polymer in the chemical mix, intended to create a thin protective layer on the car’s body after the wash is done.
Those both do their jobs. But what’s most important is the foam that this Adam’s shampoo creates. It’s thick, it’s rich, and it doesn’t quickly evaporate the way some inexpensive cannon soaps do. The pH neutral soap clings firmly to your car to loosen all of the dirt, grime, pollen and other gunk that’s accumulated, without disturbing any of the wax or sealant that may have previously been applied. That’s a long way of saying that this foam does a terrific job.
Adam’s Ultra Foam is available in gallon or 16 fluid ounce containers; for each pre-wash, you simply mix 3-5 ounces of soap with the water in your cannon’s canister, and off you go. The dwell time for this product is long and it has a grape scent, but the only thing that may convince you to move on to our next product is the cost; this foam cannon soap is one of the most expensive products we reviewed.
2. Chemical Guys Snow Foam Soap and Cleanser
This may be the most popular snow foam cannon soap in America, and for three good reasons: it performs just about on a par with the Adam’s Ultra Foam, you only have to use about 2-3 ounces at a time, and it costs about half the price. The Chemical Guys foam produces tons of thick suds that lift off most of the grime and dirt that accumulate on a car, although it does seem to slip off a little faster than the Adam’s foam soap. This is a pH-neutral product so it won’t damage any wax or sealant that’s already on your car (it can even be used on gel finishes), nor will it damage any of the rubber, vinyl or plastic.
This product is available in your choice of honeydew or watermelon scents, and if you’re looking for the less-noticeable one, go with honeydew. There’s very little to criticize here; the Chemical Guys make great products, and this one does an excellent job at a very reasonable cost.
3. Mothers Triple Action Foam Wash
Another foam cannon soap that’s blended with a polymer to lay down a protective layer after the wash, Mothers 3X is a heavy-foaming product which does its work well. It removes almost all grime, dirt and other accumulated contaminants, although it won’t protect wax jobs quite as well as a pH-neutral product because it’s only “pH-optimized.” Unfortunately, there are no numbers supplied to know how close to pH 7.0 the Mothers foam really gets. We couldn’t quite identify its scent either, but it’s not overwhelming.
Be aware that the “Triple Action” description in the product name doesn’t mean this foam does anything special; it simply means you can use different amounts of the product to create “all-purpose,” “extra strength” or “ultimate power” soap. You’ll want to choose option two or three for use in your foam cannon, which means three or five ounces respectively. That’s a good deal, since on a per-ounce basis this foam wash is even less expensive than the Chemical Guys cannon soap.
4. Sun Joe Premium Snow Foam Soap
We didn’t even know that Sun Joe made soap; we’re much more familiar with their lawnmowers and their Snow Joe snowblowers. They do, though, and this is decent cannon soap. It’s actually a high-viscosity biodegradable soap and while it does a good job soaking off the gunk on your car, its foam isn’t as thick, strong or effective as the chemical-based solutions we’ve already discussed.
To be honest, the best use of this Sun Joe product is probably as a regular car soap rather than a snow foam. That’s because it’s not concentrated; Sun Joe recommends using the soap undiluted in your foam cannon, which doesn’t give you any ability to adjust the strength of the solution for differing amounts of dirt.
You don’t have to worry about this soap damaging wax finishes, not because of its pH, but because the biodegradable formula makes the foam harmless to paint and other substances. Also bear in mind that you’ll use up a gallon of the Sun Joe soap much more quickly than you will use a gallon of concentrate, making the effective price of this product relatively high.
5. Bilt Hamber Auto Foam Soap
Bilt Hamber is a revered name in the auto detailing world, and this is one of their car wash offerings. It’s another biodegradable soap with a very high pH, but it’s easy on paint because it doesn’t have caustic ingredients in it, and it’s easier on the wallet than Sun Joe’s product since it’s a concentrate and won’t be used up in just a couple of washes.
The foam it creates (made from about ½ liter of concentrate mixed with a gallon of water) is thinner than the ones we’ve discussed previously – so you could color us doubtful initially. Bilt Hamber knows what they’re doing, however. The foam cannon soap’s surfactants do an outstanding job of removing tough dirt and grime, with about a five minute dwell time.
The price for a five liter jug is rather high, and the jug will only last about ten washes at recommended dilution levels. But if you can get past the fact that the foam seems to drip off pretty fast, you’ll find that your car is nearly clean and ready to be sponge washed for the finishing touches. Surprising and pretty impressive.
Factors to Consider in a Foam Cannon Soap
The most important attribute of a great foam cannon soap should be obvious: foam. You need lots and lots of foam, since it’s the combination of pressure from the water cannon and suds from the soap that makes this type of pre-wash so effective.
Regular detergents won’t cut it; they don’t create enough foam. You may be able to get away with using car wash soap instead, but you have to dilute it properly – and even then, your car probably won’t get as sparkling clean as it does when you use foam cannon soap.
Since you’ll have to buy soap no matter what, why not start off with the right snow foam soap in the first place?
Soap Designed for Foam Cannons
Believe it or not, foam cannons are very different than foam guns. You probably know that cannons are attached to power washers and guns hook up to your garden hose, but that’s not the only difference.
Foam cannons are able to accommodate thicker soap than guns, and when your goal is to effectively pre-wash a vehicle, thicker is better – because it means more cleansing foam.
Some car wash soaps claim to be multi-purpose cleaning agents which are suitable for hand washes, foam guns and cannons. A few soaps actually are usable in both guns and cannons, but chances are slim that any car soap will create enough foam to do a proper pre-wash.
Why is the volume and quality of the foam so important? It’s because foam effectively soaks the grime, dirt and grease that builds up on vehicles, softening them and then chemically breaking them up so they come right off with the swipe of a sponge.
You’d have to scrub forever to loosen and remove all of that dirt. And that’s not advisable because the scrubbing process causes streaks and is the number-one cause of scratched finishes on cars.
So foam is the key; you want lots of it, you want it thick, and you want it effective. Effectiveness is the second thing to look for.
There’s no easy way to compare the actual cleaning agents in two different snow foam soaps. They’re all basically just shampoo, and most contain chemicals to enhance their cleansing ability (although some are biodegradable). Many come with fancy descriptions like “cutting edge formulations” or “chemically advanced,” but don’t explain why they purportedly work so well.
In truth, a soap’s specific ingredients don’t really matter as long, as it’s a good product that creates a lot of concentrated foam (like the ones we’ve included in our reviews).
What matters more is that they’re a concentrate rather than a straight-out-of-the-bottle product. Concentrate allows you to adjust the amount of soap you mix with water; you can use less for a regular weekly wash, or a higher concentration if you’ve been driving in messy weather or taking your off-road vehicle through difficult terrain.
You’ll see some foam cannon soaps advertised as “deep cleaning” – be careful with those. They’re formulated to remove almost everything except perhaps road tar, and they do it well. (A soap labeled “decontaminating foam” is what you’re looking for to remove tar or iron flakes.)
The potential problem with deep cleaning foam cannon soaps, though, is that they can also remove any wax or sealant that may be on your car. In the next section, we’ll explain how to avoid that issue.
pH Neutral Foam Cannon Soap
Perhaps you remember back to high school science classes, when you learned about pH. In a nutshell, pH is how scientists measure how acidic or alkaline a liquid is. (Your teacher may have used the term “basic” instead of alkaline.) On the pH scale, “0” is completely acid and “14” is completely alkaline. “7” is right in the middle, so it’s described as neutral – and that’s what we’re looking for.
The ideal snow foam cannon soap will be a neutral solution. That means it won’t do any damage to the sealant or wax on your car’s body, and you won’t run the risk of it causing paint or plastics to peel or fade. It’s not easy to find a foam soap that tests exactly at pH 7.0 but the closer it comes, the better it is to use on your car.
Other Buying Considerations
Several other factors, all relatively minor, may be worth thinking about when shopping for the foam cannon soap.
You’ll find that most of these soaps are scented. We don’t know what would lead a manufacturer to think that the outside of a car should have a certain aroma, but they do.
You can find foam cannon soap in a variety of scents like apple or cherry, but if you don’t want your car to smell like fruit (or anything other than “car”) you should hunt for an unscented product, or at least one with a relatively mild aroma.
You’ll also see some foam cannon soaps advertised as having either a long or a quick “dwell time.” That simply refers to how long the foam has to stay on your car to do its work, before you can wash it off.
Quick dwell time may be important to you if you’re constantly in a hurry, but it’s not overly important and has no effect on how good a soap is.
There are a few foam soaps which are formulated with added conditioner or wax; some work better than others, but they won’t do as good a job as real conditioning products or waxes, and aren’t worth paying a lot extra for.
Finally, there are foam cannon (and foam gun) manufacturers who advertise that you should use their branded soap for best performance. They may make a terrific snow foam soap, but your decision should be based on the qualities of the products you’re considering. Using the cannon manufacturer’s soap is just as “mandatory” as using Ivory soap in an Ivory-branded bathroom dispenser. In other words, it’s not mandatory at all.
All of the qualities we’ve discussed are worth examining, but in the end, the best option will be the one that produces the thickest foam and cleans the best, ideally with a pH close to 7.
Everything else is primarily “marketing fluff” and shouldn’t deter you from finding the highest-quality soap – since pre-washing with a foam cannon is the ideal way to help your car look its best.