There are several different types of wash product and the choice of which one (or combination) should be use will depend upon the level of soiling, the protection on the vehicle, the presence of sensitive trims and the desire for safe washing.
In order to allow the chemical products to have the maximum effectiveness with soiling and contamination on the vehicle surface, it is important to remove as much loose debris and contamination as possible, before any chemicals are applied. The best way to achieve this is with a water jet, whether it is from a pressurized washer or simply a nozzle fitting on a hoze.
This is the least equipment intensive initial wash step. All that is required is a garden type sprayer into which the user dilutes the prewash product. Most of the products available are alkaline surfactant solutions. An additional popular component is a citrus based solvent. The product is sprayed over the vehicle surface and allowed to dwell for a short time after which it should be removed using a high pressure washer. Various concentrations of product are available but routine use dilutions of 50:1 are easily possible with a non-caustic formulation. For use on domestic vehicles, non-caustic formulations should be favored due to the possibility of trim staining and increased LSP degradation with caustic products.
Snowfoams are a high foaming prewash. They are applied through a specialized foam lance or venture system and results can vary from a thin foam to a ‘shaving foam’ consistency. As with prewashes, most products are strongly alkaline surfactant based. The foam allows the product additional time in contact with the surface without drying out. However, it has become popular to apply foam inches thick over the surface. Whilst this practice has visual appeal, it greatly reduces the effectiveness of the product since much of the active ingredient is trapped in the foam, never making any contact with the surface. The most effective foam is in fact a relatively thin film which will run off the surface over 5-10 minutes, the foam run off transporting dirt away and refreshing the area with fresh product, something that is not possible when the foam is almost immobile. Typical dilutions range from 50:1 through to as much as 500/1000:1. Typically snowfoams provide a lower level of cleaning power than the previous prewash products due to the higher effective dilutions. As a result, many products are now formulated with significant levels of caustics. Such caustic products should be used with care due to the potential for staining of trims, negative impact on LSP and user hazards whilst diluting.
TFR products are the traditional product type used for industrial and vehicle cleaning. They are applied via pressurized dosing equipment, typically at levels of 0.5-5%. Commonly these products are high in caustics because the vehicles being cleaned do not have sensitive finishes which may be degraded, do not have wax and LSP on the surface and they are used in a commercial environment with safety precautions available. These should be used with care on domestic vehicles unless a non-caustic or low caustic formulation is used.
Shampoos are blends of surfactants which are designed for hand use. Due to the application method, shampoos are very mild so as not to produce skin irritation in users. Depending upon the blend, shampoos can range from having copious amounts of flash foam through to moderately low foam in character. Addition of surface modifiers is common to produce a range of effects including, beading, sheeting as well as giving a slick feeling when a sponge or mitt is moved over the paint surface.