Vehicle seats are just one of the many interior and exterior surfaces that professional detailers must properly maintain. Just like any other vehicle surface, they require specialized cleaning and protection. As a point of vocabulary clarification, the word “upholstery,” refers to the covering (and padding) of a seat. Many think of the term upholstery as referring only to cloth seats. In truth, a seat may be upholstered in any number of materials.
The upholsteries typically used in automotive applications are natural materials like leather or suede, as well as synthetic materials like vinyl, cloth, and imitation leather.
In this article, we will discuss each of these materials and how to care for each.
During the standard interior detail process, the seats will have been thoroughly vacuumed before they are cleaned. During the vacuum step, make sure to clean any grit and debris from the seam areas. Spread the bolsters open with your hands and use a crevice tool and a soft nylon brush. I like to handle seat cleaning after taking care of the headliner and the plastic and vinyl panels (like the center console and dashboard), so I have a place to sit without worrying about dirtying the seats.
You will find that, in newer vehicles, the most common upholstery is leather. Leather is produced by processing rawhide (typically cattle) by tanning. There are several ways to tan leather, but the end result is that the tanned hide is more durable and relatively resistant to natural decomposition.
Automotive leather is typically coated with a color coat to match or complement the interior color scheme of the vehicle. This color coat is often top-coated with a durable but flexible clear coating as well. We think of leather as being “dyed” but the coating that is used on most automotive leather is better thought of as “paint,” because this coating is only on the surface. As such, the coating can wear off over time and with heavy use.
For example, it is common to see the outside bolster of the driver’s seat bottom and back worn from the rubbing that naturally happens as the driver enters and exits the vehicle. The coating will eventually wear off completely, leaving exposed bare leather. You can tell it’s bare leather because when it gets wet (e.g., with your leather cleaner), it darkens. You will occasionally have a customer who asks if you can “clean this off” and you have to clearly explain that the leather coating is worn off, not just dirty.
Some vehicle seats are cleverly labeled “leather trimmed.” This means that only certain bolsters of the seat are actually made of leather, while the rest can be upholstered in vinyl, synthetic leather, or even cloth. Sometimes it can be difficult to determine whether or not the material is leather or vinyl, as vinyl grain-stamping techniques can closely imitate leather grain and feel. (Take comfort, for I, the supposed “expert,” have been fooled more than once!).
One way to detect the difference is to push your thumb down into a panel, yielding a wavy “hill-and-valley” pattern around your thumb. As you press down, look into the “valleys;” if you see tiny wrinkles within the valleys, you are probably dealing with leather. Vinyl will not produce these wrinkles. Additionally, over time leather will naturally develop scuffs and character lines.
If you are not sure, simply treat the upholstery as if it were leather. The cleaners and conditioners recommended for use on leather are also safe on vinyl. However, the cleaners used for vinyl seats are not necessarily safe for leather.
After vacuuming, the leather seat can be cleaned using automotive leather cleaner, a natural bristle brush, and a utility towel. Be sure to use a cleaner designed specifically for automotive leather; other cleaners may be too harsh for the coatings typically used for automotive leather. Spray the cleaner onto a section of the seat, then agitate with a soft hogs-hair or horse-hair brush. Wipe away the remaining cleaner and dirty residue with a clean utility towel. A terry towel works fine but some technicians prefer to use a microfiber.
There are some newer scrubbing devices for automotive leather that can be particularly effective on well-used seats that have a heavy build-up of grime. Body oils, sweat, and lotions can leave the seat coated with a hard-to-remove film that makes them unnaturally shiny and appears almost as if the dirt has been painted on.
Some technicians favor the use of melamine sponges or mild scrub-sponges in this situation. Please be aware that these scrubbing devices, while they are effectively removing the grime layer, are probably also removing some of the original coating of the seat. Nonetheless, sometimes this is necessary to get all of the dirt off the seats.
Steam is another option for cleaning leather seats. A commercial-grade steam machine with a triangle nozzle wrapped with a white terry towel is typically used. The super-hot steam vapor is an effective agent to loosen and remove the built-up grime. That same vapor is also terrific for sanitizing the leather surface at the same time. Care must be taken when using steam as it can remove some of the original leather coating.
Tougher stains can be carefully spot-cleaned using stronger chemicals. Pour some of the chemical onto your towel (not onto the leather directly) and gently rub the stain. Check the towel for signs that the leather dye is coming off — stop if there is any question about color fastness. Some stains soak into the leather and cannot be completely removed. Any time you have a problem removing stains from leather, explain to the customer that you are concerned about using the harsh chemicals that might be necessary to completely remove the stain, as doing so may cause more harm to the leather than good. Then suggest that the area be re-dyed.
Treat automotive leather with the same decision tree you would use for exterior paint: “Use the least aggressive method that effectively” cleans the leather. Obviously on newer cars or cleaner leather, a soft brush or even a microfiber towel might be enough. On super-dirty and grimy leather, you will have to use more aggressive scrubbing devices, but clear this with the customer first.
Once clean, the leather needs to be properly conditioned. Use only leather conditioners designed for use on automotive leather. Using saddle products or those for furniture leather may actually damage the coatings typically used for automotive leather. Apply your conditioner liberally, allow it to soak in, then buff off the excess with a clean utility towel. I recommend using a conditioner with ultraviolet blockers, as the sun is the one element that will cause the most damage to leather, next to normal use. Do not use dressings designed for conditioning vinyl.
Seats upholstered in vinyl are not as common anymore — but not extinct. It is commonly used in non-automotive high-use applications like boats, golf carts, and construction vehicles.
Vinyl is basically flexible sheets of plastic. Seats upholstered in vinyl can be easily cleaned using a new style of all-purpose cleaners that are designed specifically for interior vehicle surfaces. We no longer recommend using a highly diluted all-purpose “cleaner-degreaser” for vehicle interiors, as these chemicals tend to be high-pH and thus not safe for the surfaces, even when diluted.
Spray the cleaner directly onto the seat, scrub with the brush, and wipe away the remaining cleaner residue and dirt with a microfiber towel. You can use stronger chemicals to spot-clean tougher stains, but be careful as some chemicals will permanently discolor (whiten) the vinyl.
We generally use vinyl and plastic dressing on most surfaces inside the car. Vinyl seats, however, should not be dressed using standard dressing, which can leave the seats slippery. Instead, dress vinyl seats using automotive leather conditioner.
The choice of many professionals for cleaning cloth seats has turned to using steam. This technology infuses much less moisture into the seat cushion than does the traditional hot-water extractor. Additionally, steam sanitizes as it cleans, which is a real bonus for the customer.
On the chemical front, there are several new “fabric cleaning systems” available that use separate chemicals to attack different parts of the problem. For example, enzymic fabric cleaners help to convert stains into easily removed components. Alkaline fabric cleaners loosen dirt so that it is easier to remove. And a follow-up peroxide treatment will neutralize any remaining chemical and leave the fabric sanitized and odor-free.
Occasionally, you will find a seat partially upholstered with suede, usually just the center bolsters. True suede is actually the rough side of leather, finished to have a velvet-like nap. So “leather” seats have a smooth finish, “suede” seats have a soft nap finish. There are also several synthetic forms of suede, including brand names like Alcantera and Ultrasuede. These are actually microfiber imitations that are sometimes used because they tend to be more resilient and stain-resistant.
The care of suede, either genuine or synthetic, starts with dry brushing. You should have a suede brush on hand (available from a shoe store or furniture store), but, in a pinch, a stiff-bristled (clean!) nylon brush or even a wire brush can work, if used carefully. Some companies offer suede cleaners, although it is generally recognized as being inadvisable to over-dampen this material. The newer interior surface cleaners available from several manufacturers can be applied to a microfiber and then gently rubbed on the material.
Often, several materials are used to upholster a seat. For example, a common description used by auto manufacturers is “leather trimmed.” This typically means that some of the seat, usually the seat face, is upholstered in leather and the rest in vinyl. Only in the finer vehicles is the entire seat (front, face, sides, and back) covered completely in leather. Similarly, some fabric seats have vinyl side panels and backs.
When in doubt about whether it’s vinyl or leather, treat it as leather. Other mixed upholstery can be dealt with by carefully using the recommended procedure for each panel, according to its composition.
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 firstname.lastname@example.org.