By Bryan Couch
Motor Coach Industries
Keeping a coach free from rain, dust, tree sap, road splash, salt and other de-icing chemicals is an impossible feat. Keeping it clean doesn't have to be. Regular care and maintenance of a coach's exterior will keep a coach looking new, longer and protect your investment.
How often a coach should be washed depends on the environment in which it is operated. In extreme winter conditions, wash salt and de-icing chemicals from the body and undercarriage daily to prevent corrosion.
Recent studies suggest that commonly used road salt is more corrosive to a vehicle than the newer road de-icers and anti-icing agents. However, these new chemicals, which are sprayed on roadways in advance of snow or freezing rain, tend to adhere more strongly to vehicles than salt and are consequently more difficult to wash off, causing or exacerbating vehicle corrosion. Due to the increased use of de-icing chemicals and their corrosive properties, it is critical to inspect undercoating and to touch up any chipped or damaged areas on the vehicle.
A well-cleaned coach begins with the right detergents, brushes and washing sequence. To preserve a factory finish, do not use alkaline cleaners on aluminum, iron or steel. Do not use abrasive cleaners, polish or steel wool. These remove the protective coatings and can scratch and discolor the finish.
To start, wet down the coach using a high-pressure water spray with a solvent-based dissolving detergent to remove grit before brushing. Motor Coach Industries recommends a non-abrasive, neutral pH (range 6-8, non-acidic and non-alkaline) detergent for its coaches. Dupont, maker of most paints used on MCI coaches, recommends power-wash water temperatures not exceed 80 degrees Celsius (176 degrees Fahrenheit), and that the distance between the spray nozzle and painted surface be about 1.5 meters or almost 5 feet.
Follow the pre-wash with a clean water rinse. Both wash and rinse water should be free of grit. Then begin brushing the coach, either by hand or through an automatic bus wash, using a highly lubricating detergent. MCI recommends tampico-fibered brushes, however, soft cloth or felt brushes can also be used. The final rinse should be high-pressure. Wash steel and Dura-bright wheels the same way. Buff aluminum wheels periodically to keep their shine.
To remove tar, ink marks and graffiti from paint, use a soft cloth saturated with isopropanol or an aliphatic hydrocarbon solvent. MCI recommends an antistatic cleaner such as Like-Magic N1-5 or Trend on Lucite windows.
MCI recommends hand-washing for coaches newer than 60 days. Do not use high-pressure washers until the paint has cured and hardened - 30 to 60 days-depending on the humidity and regional temperatures. Wait one week before washing the coach after graphics have been applied to assure the adhesive has cured. Keep the water warm (122 degrees Fahrenheit, 50 degrees Celsius) for routine washing of coaches with decals, and keep the power spray farther away from the body.
Washing a coach presents an opportunity to check for body damage, rust and corrosion, glass cracks, loose bolts, door seals and exterior lights and mirrors. Repair anything that needs to be fixed. Window and windshield cracks may spread, especially in cold weather. Repair small depressions, scratches or pits in Fiberglas with body putty. Large holes and torn sections require resin repair.
Repair any damage to the finish of a coach as soon as possible. Using the same paint product as the original finish will ensure the best possible color match. Paint being applied to coaches today has advanced UV screeners that make it resistant to fading. If a coach is properly maintained, the paint should last the life of the coach.
Brian Couch is director of product development at MCI.