Auto Laundry News - November 2013

IDA Certification — Study Guide: Detailing Chemicals, Part I

By Prentice St. Clair

Continuing on with the “study guide” for the Detailing Certification Tests offered by the International Detailing Association, this month, let’s look at the test module that focuses on detailing chemicals.

Automotive detailing involves the cleaning and protection of the various surfaces of the vehicle. The professional detailer, then, strives to become an expert at maintaining the myriad of surface materials that compose the interior and exterior of the vehicle. On the exterior, we have painted surfaces, rubber, vinyl, plastic, glass, and sometimes chrome and aluminum. On the interior, we have vinyl, plastic, leather, carpet, fabric, and glass. Each one of these surfaces requires specific care to maintain the appearance.

Fortunately, the multitude of detailing chemical manufacturers has provided the detailing industry with specialty products for each of the vehicle surfaces mentioned above.

In fact, many detailers become confused when trying to sort through
the dozens of offerings from each manufacturer, not to mention the “stories” floating around the industry about what you can and cannot use on a vehicle.


An unfortunate, common mistake in the detailing industry is to use the wrong chemical. This mistake is best corrected with education about detailing chemicals as well as vehicle surfaces.

“Use the chemical that is appropriate for the job at hand.” This should become a daily “mantra” for the detailing professional. As mentioned earlier, the detailing chemical manufacturers have created chemicals that are specifically suited for each surface on the vehicle. To avoid damaging the surfaces, it is important to use only the chemical that is specifically designed for the surface being treated.


It is not necessary to have a chemistry degree to use detailing chemicals, but there is some background information that will help the professional detailer. Let’s start with the pH scale.

The cleaning chemicals that we use (degreasers, all-purpose cleaners, wheel cleaners, etc.) can be rated on their strength based on the pH value of the chemical. The pH scale indicates the concentration of hydrogen ions in the chemical. (For those who might be interested, the technical definition is, “the logarithm of the reciprocal of hydrogen ion concentration in gram atoms per liter.” For example, a pH of 5 indicates a concentration of .00001 or 10-5 gram atoms of hydrogen ions in one liter of solution.)

The scale goes from 0-14, with 0 being “most acidic,” 14 being “most basic or alkaline,” and 7 being exactly pH neutral. Chemicals that have a pH range of 0-6 are generally considered acidic. Some examples of common liquids that are pH-acidic include:

  • Soft drinks (pH 3.9) — ever notice that drinking too much pop gives you acid indigestion?
  • Vinegar (pH 2.2-2.4) — tastes sour, right?
  • Lemon juice (pH 2.3) — tastes really sour, right?
  • Stomach acid (pH 1.0-3.0) — no wonder they call it “acid” indigestion.

Chemicals that have a pH range of 8-14 are generally considered basic. Examples of common liquids that are pH-basic include:

  • Milk of Magnesia (pH 10.5)
  • Household ammonia (pH 11.9) Chemicals that have a pH range of 6-8 are generally considered to have a neutral pH. Examples of common liquids that are near pH-neutral include:
  • Cow’s milk (pH 6.4)
  • Blood (pH 7.4)
  • Seawater (pH 7.0-8.3)

The pH measurement tells us a lot about not only the strength of the chemical but also the safety of that chemical. In general, chemicals that have a neutral pH do not react with human tissue. Hence, spilling milk on your hands does not usually lead to any kind of burn; swimming in the ocean does not irritate your skin; and blood courses through our arteries and veins without destroying them.

On the other hand, chemicals that are on either end of the pH scale can be quite damaging to human tissue. When we think of dangerous chemicals, we tend to immediately go to low-pH acids, and with good reason. But it is just as important to think of high-pH alkaline cleaners as dangerous. For example, a high-pH engine degreaser can damage your skin by chemically burning it. Also, you may have noticed that even “mild” degreasers or all-purpose cleaners often have a label warning against excessive contact with skin, which might cause irritation.

High-pH or basic chemicals are also called caustic. You may have seen a tanker truck on the road with a hazard diamond that is black and reads “Caustic.” From the above information, you now know that the tanker is carrying a chemical that is high on the pH scale. The technical definition of caustic is “capable of burning, corroding, or destroying living tissue.” Again, sounds just as bad as acid.

So, in the realm of our detailing chemicals, we need to be aware of the pH of cleaners that we use. Just as a very high- or very low-pH chemical can damage our skin, it can also damage vehicle surfaces.

Among the very low-pH chemicals that we use are hydrofluoric acid wheel cleaner (used to remove caked-on brake dust) and oxalic acid (used to remove heavy concentrations of rail dust or environmental fall-out). Among the very high pH chemicals that we use would be a heavy-duty alkaline cleaner or degreaser.

Among the neutral pH chemicals we use are car wash shampoo and automotive leather cleaner. Carpet cleaners and all-purpose cleaners are above neutral on the pH scale, but generally not dangerous because they are designed to have just enough strength to clean carpets and other materials without damaging those materials.


A very important concept to understand about the pH of a chemical is that it does not change by adding water. For example, a hydrofluoric acid wheel cleaner may have a pH of close to 0. Diluting the acid with water according to the label directions will not change that pH value. What will change is the speed at which the chemical reacts with the surface upon which it is used.

Thus, we never use full-strength wheel acid on wheels, because it will immediately start etching into the wheel paint. However, the appropriate dilution of wheel acid will work just fast enough to loosen the brake dust so that it can be immediately scrubbed and rinsed away, before the acid starts to work on the paint. But since the pH of the diluted acid is the same as the concentrate, if you leave the acid on the wheel, it will eventually start to etch at the paint.
Hence, it is recommended that wheels that have been cleaned with acid wheel cleaner and then rinsed, also be sprayed with alkaline all-purpose cleaner and rinsed again. This “alkaline wash” will help to neutralize any remaining acid that might be on the wheel. This is also the reason why acid wheel cleaners should never be used on any interior surface, regardless of the dilution.

Even if the area is thoroughly rinsed and neutralized, it is possible for any remaining acid to continue to eat away at the material, eventually causing irreversible harm.

This concept of dilution not impacting the pH of the chemical also applies to heavy-duty alkaline cleaners and
degreasers. It is incorrect to think that diluting a strong degreaser makes it safe to use on interior surfaces. On the other hand, it is not necessary to “neutralize” caustic cleaners with an “acid rinse,” because the water-based alkaline cleaners will generally completely rinse away with the right amount of water.


This leads into a discussion about using the right chemical for the vehicle surface being treated. I encourage you to dispense with the idea that it is okay to use one “all-purpose cleaner/degreaser” for all inside and outside surfaces. A mild, near-neutral pH cleaner is appropriate for interior surfaces.

A stronger pH cleaner is recommended for exterior cleaning like wheels, rocker panels, and bug removal. Use a heave-duty degreaser only in the engine bay and on very dirty wheels and lower panels.

Tar and grease remover is great for cleaning kicked-up tar that doesn’t come off during the normal wash. It can also be used (carefully) to remove glue and adhesive, as well as tree sap.

To clean automotive leather, use a chemical designed just for automotive leather, which requires a near-neutral pH formulation to avoid damaging the leather. Follow with an appropriate conditioner, again, designed specifically for automotive leather. Since heavy-duty cleaners are generally high in pH, they are virtually never recommended for standard leather cleaning.

For general cleaning of automotive carpet, use a cleaner that is designed for that material. This is generally going to be a slightly alkaline formulation. Always try your carpet cleaner first; remaining stains can be treated carefully with stronger chemicals, limiting their use to just the stained area. Usually, a carpet stain remover will work just fine. If you happen to know for sure that a dark stain was caused by grease, a light application of degreasing cleaner or tar/grease remover is called for in this situation. Follow any special chemical application with a second cleaning with your normal carpet-cleaning chemical in order to completely remove the stronger chemical.

One detailing chemical that deserves mention here, even though it does not flow immediately from the current discussion, is fabric protectant. This product, applied to thoroughly cleaned carpeting or fabric, will help to repel spilled liquids, giving the vehicle owner time to wipe up the liquid before it soaks in. Fabric protectants may help reduce staining but will not permanently protect carpet and fabric from stains.


Well, I hope that this discussion has opened your mind to the importance of knowing what chemicals you are using. Remember that very high pH (caustic) and very low pH (acidic) chemicals are both dangerous to you and to vehicle surfaces. Using the correct chemical for the surface at hand will help to reduce this danger. Look to future months for a continuation of this discussion of detailing chemicals.

The International Detailing Association offers it’s Certified Detailer program to both members and non-members. It is the only independent certification currently available to professional detailers. The program currently consists of 10 tests that assess the taker’s background knowledge of detailing. This month’s column is one in an on-again-off-again series that is designed to present a study guide for those interested in taking the tests. Get more information or sign up for the tests at

Prentice St. Clair is president of Detail in Progress, a San Diego-based automotive reconditioning consulting firm. To contact him, e-mail or call (619) 701-1100.

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