A question we often get is which pH neutral shampoo is best. At first we always ask for what reason the customer specifically wants a pH neutral shampoo. Usually we then get the answer, “I don't know, everyone always talks about a pH neutral shampoo so I guess this is the best?”. Before we can decide which shampoo is best for you and whether you even need a pH neutral shampoo, it is important to first know what pH neutral actually means.
What is pH?
pH Is an acidity of aqueous solutions, which includes car shampoo. The lower the number the more acidic the shampoo is. The opposite of acid is alkaline and so the higher the number, the more alkaline the shampoo is. The pH scale goes from 0, which is extremely acidic, to 14, which is alkaline. pH 7 to pH 7.9 is neither acidic nor alkaline, which is why it is considered pH neutral. Alkaline shampoo and often rim cleaners are also called pH “balanced”. Do not mistake this for pH neutral as balanced is not the same as pH neutral!
What is a pH neutral shampoo?
So now that we know what pH neutral means, when is it important when choosing a shampoo? Well, actually it doesn't. You would think that you would not want to get an acidic or alkaline shampoo on your car because you think it will damage your car. But this is not the case with almost any shampoo. Certainly the shampoos that are available for individuals are often not harmful to the car. What people often talk about is that pH neutral shampoos do not strip paint protection from the car because alkaline shampoos would. Well, unfortunately this is not entirely true either.
pH Neutral shampoos are indeed generally “gentler” on paint protection such as wax, sealant and coating. But this is also certainly not always the case. There used to be only 2 options in shampoos, pH neutral and alkaline. pH Neutral shampoos were only put on the car as a “lubricant” during washing and had virtually no cleaning properties. And the alkaline shampoos were so aggressive that a wax or sealant would not survive any wash and professional detailers would also feel it on their hands if they washed cars every day with the alkaline shampoo without protective gloves. Today, however, so much has changed and we have learned a tremendous amount about chemicals that this is no longer the case.
As an example, let's take isopropyl alcohol, which is also known as disinfecting alcohol or degreaser. If we were to measure the pH value of “IPA” it would be exactly 7.5, which is pH neutral. If we were to follow the logic of many people this means that it is therefore safe for paint protection such as wax and sealants? And as many of you already know, this is anything but the case. From the moment IPA comes into contact with wax or sealant it immediately starts to dissolve and remove the protection. So this is the same with many other chemicals. There are car polish and detailing brands that advertise their shampoos as pH neutral which makes the customer think that it is safe for their protection like their wax and sealant but it still has chemicals in it that dissolve it so you have to reapply wax or sealant faster and thus buy more of their products and they earn more from you! Therefore it is important that you buy your shampoo at a sensible store that can guarantee you when you buy a pH neutral shampoo that it really is neutral without other wax or sealant dissolving agents. We extensively test all of our shampoos to be safe for wax when sold as a pH neutral shampoo and to be of high quality.
What is an alkaline shampoo?
Now that we know what a pH neutral shampoo is or at least should be, namely a shampoo that should mainly glide well on the paint and not affect the protection. So what exactly does this imply for alkaline shampoos? Well, don't be put off by the fact that in the past professional detailers had to wear protective gloves when using alkaline shampoos because otherwise their hands would get sore. Although we still do this as it is a small effort and never hurts. For someone who only washes their car once a week, it generally doesn't hurt to wash your car with an alkaline shampoo without protective gloves. However if it is indicated on the packaging we do of course recommend doing so.
So does an alkaline shampoo also mean that it is going to take off the wax, sealant or coating? Or maybe even the paint itself or the plastic parts? Well, not really no. Alkaline shampoos are primarily made to clean really well. Just as pH neutral shampoos are generally made to glide on the paint especially well. Alkaline shampoo doesn't necessarily look at paint protection, but mostly at dirt. Alkaline shampoo wants to get all the dirt off the car as well as possible, preferably with as little touch as possible. Alkaline cleaners are often much better at removing dirt than pH neutral shampoos. But this does not necessarily mean that it also removes the wax, sealant or coating along with it during the wash.
Is an alkaline shampoo safe for my wax, sealant or coating?
In general, coatings can tolerate most compared to a wax and sealant. At Gtechniq, for example, one of the world's best manufacturers of coatings in the automotive industry, their Gtechniq Crystal Serum Light coating can accept pH values between pH 2 and 12. Any liquids below pH 2 and above pH 12 is already going to extreme and you're not likely to find it in rim cleaners, shampoos or other cleaners either. Although this is also not to say that if you use a shampoo of pH 14 that this will immediately remove the coating. If the shampoo is pH 14, it is diluted by water which means that the pH value also drops, and the coating is still extremely strong and does not simply disappear after 1 wash. Of course we are also talking about Gtechniq coatings for which we guarantee top quality, we can't talk about other brands that we don't distribute. That is why it is always important to choose a professional detailer with knowledge of products!
So using an alkaline shampoo on a coating is not a problem, but what about sealants and wax? These often have a lower tolerance for pH levels, does this mean they will be removed after a wash with an alkaline shampoo? This is not necessarily the case no. If we assume that we select an “honest” detailing brand that has both a pH neutral and an alkaline shampoo then you can usually say that this will indeed strip the wax or sealant. This is because if you want to preserve your wax or sealant it is best to just go for the pH neutral shampoo, and if you really want to clean it is best to just go for the alkaline shampoo that doesn't take into account the wax or sealant and just takes away as much dirt as possible. But there are also many alkaline shampoos that take away little to no wax or sealant while washing.
Why a pH neutral car shampoo?
Well usually if one wants a safe shampoo then they choose a pH neutral shampoo so that the wax or sealant stays on the car. As we already know now we don't have to worry about coatings if we have a good coating and shampoo. The wax and sealant ensure that there is a small protective layer between the paint and the dirt so the car is usually less dirty and the dirt also dissolves better and faster. With a good wax and sealant, if the car is dirty and is hosed down with water, it is often the case that the paint is already pretty clean right away so there is less chance of making scratches during washing.
The small protective layer of wax or sealant also reduces the depth of these scratches. So the important thing in this case is that the shampoo glides well, which reduces the risk of scratches even more since the paint will be clean anyway if you go over it lightly with a microfiber mitt. The shampoo does not really clean the dirt, it is the mitt that takes the dirt away. The shampoo is actually only there as a lubricant. And so when we have a good wax and a good shampoo then after the wash we see again the clean paint with a radiant shine from the wax and sealant with water repellent properties and tight beadings. So that way you don't have to reapply your wax every time you wash your car. If you have the impression that your wax or sealant disappears quickly, it may be due to the shampoo and it is time to switch to one of the shampoos that we offer.
Why an alkaline shampoo?
We choose an alkaline shampoo mainly when we need a strong shampoo that removes as much dirt as possible. We prefer alkaline shampoos that do not take wax or sealant into account and just work best of all shampoos to remove dirt. There is still a difference between alkaline shampoos that remove dirt and preserve the wax and sealant versus alkaline shampoos that remove dirt without regard to wax or sealant. The shampoo that does not have to take anything else into account but dirt can of course contain the best chemicals to remove dirt, which are often not proportional to wax and sealant so they work better.
For dirty cars we always prefer an alkaline shampoo that removes dirt rather than a pH neutral shampoo that glides over the paint better. Especially if a car will be treated with clay or has to be polished or needs a wax or sealant, it is also important that the previous wax and sealant is gone and also in this case an alkaline shampoo that does not take a wax or sealant into account is the best choice. If your car is treated with a wax or sealant and is still quite dirty, it may be more interesting to use an alkaline shampoo that takes into account the wax and sealant. This is all best judged by the person who will wash the car, of course.
When to choose a pH neutral car shampoo and an alkaline car shampoo?
So to get everything straight, it's best to differentiate the amount of dirt on the car, any protection and whether you want to keep it or not.
- Your car has wax, sealant or coating protection and is still in good condition and is still pretty clean. You also want to preserve the wax or sealant and certainly not take it off. Then go for the safe pH neutral car shampoo in both foam lance and bucket.
- Your car has a wax, sealant or coating protection and is already somewhat weathered. The car is also quite dirty but you still want to preserve the wax or sealant as much as possible. Then go for an alkaline car shampoo that can still retain the wax and sealant properly in the foam lance and use a safe pH neutral shampoo in the bucket.
- Your car has wax, sealant or coating protection and is already significantly cured. The car is also extremely dirty and at this point you want to protect the paint as much as possible from scratches. Then go for an alkaline shampoo that does not consider wax and sealant in the foam lance. After the pre wash and you have hosed off all the dirt inspect whether the car is still hugely dirty or not. If it is still quite dirty choose the alkaline car shampoo that does not consider wax or sealant in the bucket. If the car is pretty clean now you can opt for the safe pH neutral shampoo for extra lube in the bucket.
- Your car does not have a wax or sealant. Or your car is protected with a good coating. At this point, it doesn't matter if the car is unprotected or has a good coating before the pre wash. It also doesn't matter if the car is as good as clean or hugely dirty. In this case we always choose an alkaline shampoo in the pre wash that does not take wax or sealant into account. We just want to remove as much dirt as possible before touching the car. So in this case, go for the alkaline pre wash car shampoo that does not take into account wax or shampoo in the foam lance. If after this the car is as good as clean then you can wash it with a safe pH neutral shampoo for maximum lubrication. If the car is still dirty then you can use alkaline shampoo again in the bucket.
Conclusion on car shampoo
As you can see, choosing the right shampoo is not always easy, especially with the tricks that some brands use to make extra sales. So choosing the wrong shampoo can cause you to scratch more paintwork compared to a correct shampoo, make you spend longer than you should when washing your car, spend more money on shampoos than you should, and make you wax or sealant your car faster and more.
There is a lot more to a car shampoo than most people think. A lot of professional detailers and stores do not have this knowledge or even worse, sometimes give you the wrong shampoo so that you buy more products than you should. That is why it is important that you buy from a store that is open and honest about the products they offer, guarantees the quality and properties and also gives correct advice. We at Custom Car Care are always ready to give you correct advice about our car shampoo and are happy to help you make the right choice from our large selection!
pH Neutral car shampoo or alkaline car shampoo?