I have been asked a few times about snow foam when I have been to car shows. I do use it now, depending on the product and how you use it can make a nice difference or leave you bitterly disappointed. When i started out with snow foam I just didn’t get it, what was I doing wrong? Combinations of equipment and product trials I eventually managed to get results worth talking about. I decided to create a little article of my own which I hope will help and guide you through the pitfalls and hype between products, or why we even consider using it. I mean it wasn’t around fifteen years or so ago so do we need it and why?

Snow foam looks amazing from a distance and often gets a few looks when you use it. Before this step was introduced, you used to get as much car shampoo bubbles on the paint to wash it right? This cleaning process has now been separated out into two steps. The snow foam and the shampoo. We will only be dealing with the shampoo step here.

Put very simply snow foam step is there to reduce the likelihood of damage to the paint during the cleaning process, a “Pre Wash” non touch step. This snow foam process is not necessarily restricted to car detailers or professionals, but also the weekend washer.

When you wash a dirty car with a sponge or a single bucket wash, the chances are that you could introduce paint damage by microscopic particles damaging the surface of your paint as they cling to your sponge or microfibre wash mitt. The deeper the damage, the worse the paint will look. I have explained these principles in depth on another article here and how to fix them. The basics are highlighted in the picture below to show the varying degrees of damage.

Common Terminology:

• Pre-wash: A treatment that helps to make contact washing your car easier and more effective. 
• Non Touch: Cleaning without any physical contact with the paint.
• Contact Wash: Any part of the washing process that touches your paint.
• Contact time: How long your cleaning solution is in contact with the dirt on your car.
• Dwell Time: How long the product needs to be left in order to work its magic.
• Foam Consistency: Thick snow foam clings to cars, so it has a high contact time. Watery snow foam will dribble off your car, less contact time and won’t be as effective. 
• Cling: The ability of the product to stick to the panels without falling off.
• Dilution: Reduction of concentrate to make the correct mixture operate effectively without waste.
• Canister: The container where the mixture is held.
• Snow Foam lance: A special nozzle for your pressure washer that turns the snow foam liquid into a thick foam. Also referred to as Snow Cannon, Snow Gun etc.
• Nozzle: The end of the lance/cannon/gun which controls the amount of product and how it applies the foam to the car.
• pH neutral: A substance which is neither acidic nor alkaline but chemically neutral.
• Water Spots: The marks left behind from the hard water drying out on the paint work.

We know that (contact) washing a dirty car will make it look better, but done wrong that short term cleanliness will be taken over by swirls, marring scratches etc. So before you even think about putting a wash mitt or similar cleaning item, the less debris that there is on the car, the better.

This is where ‘Snow Foam’ comes in. The snow foam is designed to cling to the paintwork, which will in turn moisten and loosen up any of the surface dirt. When you rinse and wash off the snow foam it should take the dirt and grime with it. This in theory will leave you with a much cleaner surface to clean with significantly reduced chances of damage to your car’s paint job.

The ideal scenario is a foam that will dwell on the paint for a while, then roll off the paint prior to rinsing taking the dirt with it.

How does a Snow Cannon work?

In a nut shell; the water pressure from the jet washer creates a syphon that lifts the snow foam mixture from the canister via a pipe into the pressurised water stream. The wire mesh inside the the cannon body agitates the mixture up into foam. More water the less dense the foam and will lasts longer. The nozzle is the key as to how the foam is sprayed onto the car, anything from a jet spray to a wide angle fan. These cannons can vary from £15 to £100 depending on style, fitting(s) and quality of build.

Misconceptions:

+ The thicker the foam the better.

To a degree this true, but what is the point of a great foam if it sticks to the car, but doesn’t clean it? If the snow foam is more like a bubbly water and bounces straight of the paint then again it has done no good. There is a happy medium based on the car’s requirements and is explained a little further down.

+ PH Neutral is a must.

If you start researching snow foams, at some point the chemical composition will show up. So all you really need to know is the difference between pH neutral and non-pH neutral (or alkaline) snow foams.

The pH obsession has arisen due to information propagated by self-professed experts on the internet. In actual fact, most damage to car finishes is caused by tiny particles stuck onto a road film or dirt that cause abrasive damage when being removed by washing with mitt or sponge. Thus inducing the swirls, hologram, scratching and paint wear depending on the severity of damage to the paint.

Even some manufacturers of ‘ceramics’, last stage products and waxes insist on a pH7 (neutral) shampoo or cleaners.

This intrigued me, so after a quick bit of Google research it showed me that the normal range for rain water is pH 5-6. (Look it up if you don’t believe me! ‘pH balance of rain water’.) This is one of the main reasons that your car wax/sealants tend to loose their effectiveness over time and need reapplication.

+ pH Differences

A pH neutral snow foam is generally gentler on your car’s paintwork, so it’s worth getting if your car is valuable or needs to look its best for a special occasion. This comes at a cost as heavy debris is still there.

A normal or regular alkaline snow foam isn’t quite as good for your paintwork, but it is more effective at removing dirt. However, you can easily mitigate some of the effects on your paintwork by giving your car a proper wash and wax, though, which will put a new layer of protective wax onto your car. If you have the protection on the car, the alkaline snow foam won’t remove the wax protection or touch the paint anyway. It’s certainly not a caustic mixture for your car.

The damage from a heavy alkaline product is; caustic soda (sodium hydroxide). This can dull and leave paint finishes matt and lifeless when used on a long-term basis.

Perhaps you may need two types of snow foam, regular maintenance wash for light soil using pH neutral product, and a stronger alkaline for the heavier soiling when needed.

+ You need a jet wash or pressure washer

Nope. The jet wash is not the be all and end all of the snow application to the car. Some snow foams are quite happy to be applied by a hand held pressure pumped bottle. As long as the foam product is the correct dilution, is applied to the paint and allowed to dwell before its removal – then its job is done.

+ All Snow Foam lances are the same

Nope. They come in all shapes and sizes. Some brass body, some made of cheaper metals or plastic. You get what you pay for.

Honestly, I had a Karcher cannon that could barely muster a lather no matter the product. The Autbrite snow cannon with the same mixture was an incredible difference. My only advise here is to make your choice wisely.

+ You must use Snow Foam

Well sort of. You could use some good quality shampoos at a push. But their pre-wash cleaning ability is not as good as the snow foams. Most car shampoos tend to have additives to allow slick washing and glide the cleaning applicator (mitt of sponge) over the paint and a level of protection. It’s best to get a product designed as a snow foam.

Types of Snow Foam:

Apart from the pH values as we have discussed above most snow foams are pH neutral. The main differences are the cost per litre when mixing for the dilution ratio. The cling properties which varies a great deal, their proclaimed cleaning properties, colour and the scent. Some of these scents are sublime; water melon, lemon, citrus fruits, strawberries, cherry, beer etc. Or nothing if just want a no gimmick product that does the job. I have used a few in my time:

Some have been worse than useless, some have been better than others and one is my now go to product.

Application:

Mix your snow foam as per the manufacturers recommendations. This is usually a ratio of around 1:10 or 1:20 etc. some are even 1:100.

Next attach the snow lance to the jet wash, adjust the mixtures and apply (if needed). This will take a little tweaking for the ideal balance between dilution ratio, the water pressure, size of the nozzle and the product you are using.

Different products on the same foam cannon will be very different and need further adjusting to suit.

Most of the products advise not to allow the product to dry out. The product can be affected by the Sun, warm paint, wind rain etc. Most manufacturers go on to say apply ‘in the shade’ and ‘apply to cool paint’ etc in order to mitigate the drying out process of the product.

Always start from the bottom and work up. The huge majority of debris and soiling is on the bottom half of the car. As you get to the top less show foam is needed.

Types of application.

A snow foam application will solidify into nothing eventually and slide off the car. If the snow is to thick it will fall of the car (no clinging properties) in clumps before it has had a chance to work. So, thicker is not always better. But it does look good below.

After a few minutes of dwell time it will look less impressive.

Some of the poorer week applications look half dead before they are applied and very watery. These products tend to run off and dry out very quickly.

If the product starts to dry out, there is no harm in reapplying more.

Some of the better quality products have ‘wetting’ agents in them to aid in keeping the product wet on the paint to avoid it drying out. This product application is a little thin now, but was taken after a few minutes. Although below looks less, it has in fact been doing it’s job well and was staying like this without additional applications.

Once the dwell time has elapsed, rinse of with a medium force jet wash. You can then wash the car as normal to avoid any water spots.

Results:

The results vary considerably by product. I have some before and after pics to show what it was before the application and what was there after rinsing.

Here is a very well known market leader product that has a very good cling and thick foam. But, it left a film of dirt and didn’t wash off the dirt.

Another very well known brand but is a cheaper product. Thin application, not very good cling and failed to wash of dirt. the dirt was still on their without being moistened.

A Premium brand, clings well, but failed to wash the dirt off completely. The dirt was moistened and was easier wipe off with a finger. So it did help.

This is well know brand to those in the detailing world. The foaming qualities not great and are to be desired. But when this runs of the paint it takes the dirt with it.

This is the result you want. The dirt and film is gone ready for a proper contact wash. It even cleaned some brake dust off!

Summary:

Don’t believe all the hype. The snow foam step is not a magical ‘foam the the car and it’s clean’ process. This foam step is to pre wash the car and should be treated as such. You need to manage your own snow foam expectations depending on the product. I have done a number of snow foam reviews on this website now.

I have been sceptical of the snow foam step even critical to a point. I saw it as the latest fad with no benefit to be honest. I have learned the hard way by working up the ladder. I tried the weaker brands which put a bit of foam on the car and emptied my wallet for no reason. I tried the big name brands which gave a great clinging foam but not much else. I tried premium brands which gave a good enough foam and decent moistening to the dirt. I tried the in the know ‘detailers’ brands. These later ‘detailer’ brands were by far the best performing of all the brands I have used so far.

Some brands are so much better than others to the point I haven’t even reviewed some of them, I used them up as a patio cleaner. After application of some brands, the dirt was not loosened and was still difficult to remove with a finger even after rinsing, like you shouldn’t do by the way. If the dirt is difficult to remove after the snow foam step then you are potentially going to washing a little harder to get the debris off the paint, in turn potentially introducing damage that you are trying to avoid in the first place.

If you are careful and use top quality shampoos with a two bucket method, then you can do away with this step as we have done for decades way before all this snow foam malarkey.

This snow foam step is trial and error which works for you. I have tried at least six products before I found something came close to something i could review or even partially liked. You may need to do the same, or look out for fellow detailer’s product reviews.