How Professional Detailers Wash a Car

Ask a professional detailer where the fine circular scratches on most cars come from and the usual answer is the wash itself. Grit dragged across the paint by a dirty sponge, a gritty towel or a brush at an automatic car wash leaves marks that show up as a spiderweb when sunlight hits the hood. A careful hand wash prevents most of them, and it is not complicated. It is mostly a matter of order.

Here is the sequence a detailer follows on a typical maintenance wash, with the reason behind each step.

1. Park in the shade and check that the panels are cool. Lay a hand flat on the hood. If it feels warm, wait. Sun and heat dry soap and water onto the paint before you can rinse them, which leaves spots and streaks, and the minerals in hard tap water can etch the clear coat if they bake on.
2. Clean the wheels and tires first. Wheels carry brake dust, which is partly iron particles, plus road grime that is far dirtier than anything on the paint. Doing them first means the splash lands on panels you have not washed yet. Use a separate bucket, a wheel brush and a cleaner labeled safe for your wheel finish, since some acidic products can damage bare, polished or coated wheels. Let hot brakes cool before spraying anything on them.
3. Pre-rinse the whole car from the top. A thorough rinse with a hose or pressure washer carries off loose sand and dust before a mitt ever touches the paint. Keep a pressure washer nozzle a reasonable distance back, particularly near trim edges, badges and any chipped paint.
4. Set up two buckets with grit guards. One holds water mixed with a dedicated car shampoo. The other holds plain rinse water. A grit guard is a plastic grid that sits at the bottom of each bucket; dirt rinsed off the mitt sinks below it, and the grid keeps the mitt from stirring it back up. Skip dish soap, which is made to cut grease and will strip wax and sealant along with the dirt.
5. Wash from the roof down with a microfiber wash mitt. Work one section at a time: roof, glass, hood and trunk, upper doors, then the lower panels and bumpers last, because they hold the heaviest grime. Use straight, light passes rather than circles, and let the shampoo do the work. After each section, dunk the mitt in the rinse bucket and rub it against the grit guard before reloading it with soap. If you drop the mitt on the ground, swap it for a clean one.
6. Rinse again, top to bottom. Rinse each area before it dries, and finish with a gentle flow from an open hose with no nozzle. Water tends to sheet off in larger runs that way, leaving less to dry by hand.
7. Dry with a large microfiber drying towel. Waffle-weave and twisted-loop towels hold a lot of water. Lay the towel flat and draw it across the panel, or blot, instead of scrubbing. A leaf blower or compressed air pushes water out of mirror housings, grilles and badges, where it otherwise dribbles out later and leaves streaks.
8. Feel the paint and clay it if it is rough. Slip your hand into a thin plastic sandwich bag and glide it over the clean hood. A gritty, sandpaper feel means bonded contamination such as rail dust, tree sap or paint overspray that washing does not lift. A clay bar or clay mitt, used with plenty of clay lubricant and light pressure, pulls it off. Clay that hits the ground goes in the trash. Most cars need this once or twice a year, not every wash.
9. Protect the paint with wax or sealant. Apply a thin coat to clean, cool paint and buff it off with a clean microfiber towel. Carnauba wax gives a warm, deep look but usually lasts only a few weeks to a couple of months. A synthetic paint sealant typically holds for several months, often four to six with regular gentle washing. Ceramic coatings can last years but need careful prep and are often left to a professional. Polishing, which removes a thin layer of clear coat to level swirls, comes before any of these; deeper scratches are a separate repair job.
10. Finish the glass and tires. Clean exterior glass with a dedicated glass cleaner and a separate towel. Products without ammonia are the safer choice for cars with aftermarket window tint. Apply tire dressing to the rubber only, with an applicator, and wipe off excess so it does not sling onto the paint or get on the tread.

Interior basics

Start by taking everything out, floor mats included. Shake or vacuum the mats outside the car, then vacuum the cabin from the top down, using a crevice tool along the seat rails and between the seats and console. A soft detailing brush loosens dust from air vents and around buttons so the vacuum can catch it.

Spray interior cleaner onto a microfiber cloth rather than directly onto the dashboard, so it does not drip into switches or onto the infotainment screen. For screens, a dry or barely damp microfiber is safest. Leather does best with a dedicated cleaner followed by a conditioner a few times a year.

Go easy with glossy, silicone-heavy dressings. On the dashboard they cause glare on the windshield, and on the steering wheel, pedals or floor mats they make surfaces slippery. Clean the inside of the glass last, after the dust from vacuuming has settled, and wipe it in a different direction from the outside so you can tell which side a remaining streak is on.