We continue the discussion of interior detailing from the last couple of months. The key to successful interior detailing is understanding the materials and how to care for them so as to bring to bear the most efficient techniques to get the job done.

            The standard interior detailing process generally includes these steps:
1.         Remove customer belongings
2.         Vacuum and air purge
3.         Check headliner
4.         Clean vinyl and plastic panels
5.         Clean seats
6.         Clean carpets
7.         Dress vinyl and plastic panels
8.         Condition leather
9.         Clean interior glass
10.       Deodorize as necessary

            Last month, the discussion focused on seats only. Since there are so many types of seat upholstery, it took the entire column to cover the care of vehicle seats. Now, let’s continue with the next step of the interior detail process, which is carpeting.


            “Carpeting” includes carpeted floor mats, as well as the carpeting on the floor of the vehicle.

            I recommend removing carpeted mats and cleaning them early in the interior detailing process (perhaps after Step 2). By doing so, the mats have a chance to fully dry — either in the sun or using air movers — by the time the detail is complete. Heavily soiled mats may need to be blasted with a pressure washer before using one of the cleaning methods mentioned below. However, do not use the pressure washer inside the vehicle.

            Cleaning of the carpet pad that is permanently installed in the vehicle floor is saved for last so that we don’t have to worry about dripping on the carpeting while cleaning the other surfaces. Of course, it has already been brushed and vacuumed in Step 2 of the process above.


            The old-style method of carpet cleaning is to use a bucket of soapy water, a stiff brush, and a wet-dry vacuum. The technician would repeatedly dip the brush into the bucket and scrub the carpeting. Then, the technician would use the wet-dry vacuum in an attempt to suck out the emulsified soil and excess soapy water.

            Another old-style cleaning technique is to use high-suds carpet shampoo, spraying the carpet with the foamy shampoo and then scrubbing it. Without proper extraction, this is mostly just spreading the dirt and stains around evenly, so the carpet appears cleaner.

            Using these two carpet cleaning techniques — shampooing or “bucket-and-brush” — requires soaking the carpeting with water or chemical in order to get it clean. However, it is difficult to get all of the soap solution back out again. Even the most powerful vacuum can’t do it. Moreover, most wet-dry vacuums do not have a specialized extraction nozzle that a hot-water extractor has. The carpets are left overly damp and with soapy residue.


            The true detailing professional will have a proven carpet cleaning procedure that includes treating the carpet with an appropriate set of chemicals that attacks both stains and soil. This will be followed by “rinsing” the carpet using equipment that effectively extracts most of the remaining dirt and chemicals.

Use the Correct Chemicals

            I often say, “Use the correct chemical for the surface at hand,” and carpeting is no exception. First, effective carpet cleaning requires two types of chemicals to remove both stains and dirt. The stain-removing chemicals will be addressed shortly.

            A common practice in high-production detailing shops is to utilize a diluted form of degreasing chemical. Unfortunately, what is often used is a high-alkaline degreaser designed to remove grease from engines, or worse, fatty food residue from restaurant cooking equipment. The ingredients in these degreasers are not safe for use inside the vehicle, even when heavily diluted. If you use these chemicals and have issues with the formation of white residue on the carpeting as it dries after cleaning, you are seeing first-hand evidence that what I am saying is true. That residue is sodium hydroxide (NaOH), a very dangerous active ingredient that can cause damage to the materials used in vehicle interiors.

            Carpet shampoo is not appropriate for use with a hot-water extractor or steam machine, as these create too much foam. The extractor’s recovery tank will quickly fill up with suds, backing up into the vacuum and causing damage to the machine. The steam machine, because of its low-water extraction method, simply cannot remove a noticeable amount of shampoo residue.

            The appropriate carpet cleaning chemical to remove dirt and soil will be a low-sudsing alkaline cleaner that is designed specifically for safe use on carpeting and fabric seats. All of the major detailing chemical manufacturers have such a product. Stop using one degreasing chemical to clean everything! And definitely no degreasers inside the car!

Removing Stains

            A common misconception is that one needs only a single cleaning chemical for carpeting, which is typically a water-based alkaline chemical that most detailing chemical suppliers specifically design for carpet cleaning. In fact, these types of cleaners are designed to remove soil and dirt from the carpet, but lack effectiveness in removing stains. For stains, a second chemical is required — an enzyme-based cleaner.

            Stain-removing enzyme carpet cleaning chemicals usually come in the form of “pre-treatment” or “spot and stain removers.” A good enzyme pre-treatment will have a combination of four enzymes, each of which specializes in attacking one of the four categories of stains.

            The four categories of stains are:
•          Tannin stains. Tannin is a naturally occurring brownish or yellowish vegetable dye found in coffee, tea, wine, some colas, and some fruit juices.
•          Protein stains. These include all bodily fluids, dairy products, and some food spills.
•          Oil-based stains. These include oil, grease, lotion, and some fatty food spills.
•          Dye-based stains. These include ink, paint, color transfer from things like new denim or leather belts, red stains from juice, red-colored drinks, and red candy. Dye-based stains can be the most difficult to completely remove.

            Only enzyme cleaners can even begin to remove these kinds of stains. The enzyme actually attacks the molecules of the stain, breaking them up so that they are easy to remove with extraction. Normal carpet cleaning chemicals may make stains look better simply because they are removing soil from the area, thus essentially “cleaning the stain,” but the stain is not truly removed.

            A common question at this point in the discussion is, “Well, why can’t we just combine enzyme and soil cleaners into one formula?” This is a valid question, and, indeed, some suppliers have done just this. However, we find that combining the chemicals reduces the effectiveness of each chemical, and that superior results are achieved by applying the chemicals separately, as described in the recommended procedure section below.

            The smart detailing operator never promises complete removal of stains in carpeting or fabric seats, but instead will reassure the customer that the materials will look “better” after servicing, thus appropriately setting the customer’s expectation. And, with this approach, if you are using quality products and effective techniques, you can deliver results that exceed those pre-set expectations, resulting in a delighted customer, even though the stains may not be 100 percent removed.

Carpet Cleaning Procedure

            The basic process of cleaning carpeting is to first loosen and emulsify the soil, dirt, and stains in the carpeting. Second, we extract the emulsion in order to remove as much soil and chemical as possible.

            Here are the individual steps in carpet cleaning:
1.         Brush and vacuum to remove loose dirt and debris
2.         Apply enzyme pre-treatment liberally and allow to dwell
3.         Scrub the carpeting that has been misted with enzyme cleaner
4.         Apply carpet cleaning solution
5.         Scrub the carpeting again
6.         Extract the loosened soil and leftover chemical
7.         Dry the carpeting

Carpet Extraction

            In short, extraction refers to the removal of as much of the loosened soil, stains, and cleaning chemicals as possible.

            Removing dirt and soil is an obvious goal. But it is also important to remove as much of the carpet-cleaning chemicals as possible. Leftover chemical can have an unpleasant odor. Also, leftover chemical residue will attract dirt faster by basically “cleaning” the bottom of the customer’s shoes.

            In the absence of machines, one can use a clean terry towel and briskly rub the treated area. A damp towel might work even better. This technique will work well for spot cleaning, but for large areas, towel buffing by hand simply cannot remove enough of the soil and chemical to be effective. Machines must be used.

            Many professionals utilize a hot-water extractor to deep-clean carpeting because it is the best device we have to do so. An extractor consists of several components, including two tanks, a clean-water “solution” tank and a recovery tank (for the dirty water); a heater to heat that water; a pump to transfer the clean water from the unit to the specialized nozzle; and a vacuum to suck away the emulsified dirt.

            Why hot water? It will loosen the dirt from the carpeting much more effectively than cold water. And the carpeting will dry faster if hot water is used.

            A hot water extractor heats the rinsing water. A good extractor delivers water at a temperature of 180-220 degrees Fahrenheit. A good extractor will also have a powerful vacuum system designed to remove as much moisture from the carpeting as possible. A unique aspect of a hot water extractor is the design of the extractor nozzle, which combines a nozzle that injects the carpeting with a fan pattern of water while almost simultaneously sucking out that water (and chemical and dirt) with a specially-designed vacuum nozzle that maximizes suction.

            I recommend not using any cleaner in the solution tank. Instead, use only clean water. This will reduce the amount of chemical left behind in the carpet. Essentially, the extractor becomes a device by which you can rinse the carpeting with hot water. This leaves little chemical in the carpet. Use only carpet cleaner that is specifically designed for use with an extractor. This chemical will be low-suds or “low-foam” so that the recovery tank does not become choked with foam.

            Another very effective option for extracting lightly soiled carpeting and mats is by using a dry-vapor steam machine, which effectively cleans the surface of the carpeting without leaving it soaking wet. The steam, which is usually quite a bit hotter than the water provided by a hot-water extractor, will also help to boost the cleaning power of the chemicals that have been worked into the carpet during the cleaning steps.

Drying the Carpets

            The carpets inside the car can be dried by using an air mover or using the vehicle climate control system. When using the vehicle climate control system, turn on the fan to full, direct the flow to the floor vents, turn the temperature control to the hottest setting, and turn on the air conditioner, which removes moisture from the air. Also, make sure to use the “fresh air” setting. Using the “recirculate” setting will keep the same hot, damp air moving around inside the car.


Deodorizing Carpets

            If you are using the cleaning techniques described above, most odor will be removed from the carpeting. If odor remains, you can use odor-neutralizing chemicals on the carpeting. Fragrance alone is not enough — it simply masks the odor for a while, whereas true odor neutralizing chemicals attack the source of the odor.

Fabric Protection

            This is a great add-on service that can boost the profitability of the interior detail with minimal labor along with some product expense. A quality fabric protectant will coat the individual fibers of carpeting, creating a barrier to liquids. Fabric protection works in most part by repelling liquids so that the customer has a chance to wipe up the spill before soaking in. Fabric protection will not completely prevent staining and soiling of the carpeting, and this should not be promised. Instead, the benefits of fabric protection are that it will reduce staining and soiling, and make future cleaning easier.


            The professional detailing technician must be expert at cleaning and protecting all of the surfaces on a vehicle. This includes carpeting, which requires specific chemicals and professional equipment for effective results. We will continue the subject of interior detailing in an upcoming issue.

Prentice St. Clair is an International Detailing Association Recognized Trainer and Certified Detailer. As the president of Detail in Progress Inc., he has been providing training and consulting to car washes and detail shops since 1999. He is available at (619) 701-1100 or prentice@detailinprogress.com.