Pre-wash cleaners, also known as ‘snow foam’ are available as either pH-neutral or alkaline formulations. Some professional or ‘trade’ pre-wash cleaners, such as those typically found at the local hand car wash tend to be quite caustic, having a pH of 10 or above. Highly alkaline cleaners have the ability to strip protective wax layers and degrade sealants; even nanotechnology-based glass coatings can be degraded by highly caustic chemicals.
‘Consumer’ pre-wash cleaners tend to be only mildly alkaline and at this level they have little or no impact at all on wax or sealant layers. It’s more common to strip wax layers by standing too close to a vehicle with a high pressure jet than by using a ‘consumer’ pre-wash cleaner. Clearly, pH-neutral pre-wash cleaners will have the least impact on existing protective layers, however they must rely solely on surfactants to remove contamination from the vehicle and as a result tend to be less effective.
Most ‘consumer’ pre-wash cleaners are not harmful to cabriolet soft tops, so getting some product onto a soft top is generally not a problem. However for cleaning a soft top it is advisable to use products specifically designed for the purpose, in order to ensure colour and performance of the material is not affected.← Car Care & Detailing Guides