Finishes
Many customers in the heavy duty sector require their exhaust systems to be coated,
either for cosmetic reasons or to prevent corrosion. Where a black finish is required
this can be achieved using either heat resistant paint or powder coating, which
can withstand temperatures of 600 C and 500 C respectively. In either case, correct
surface preparation and curing is required in order to achieve a durable finish.
An alternative coating method often used for large silencers which are exposed to
the elements is metal spraying using molten aluminium. This gives very good corrosion
resistance. Coatings can also be used to reduce surface temperatures, and the leading
technology in this area is currently a zirconium based ceramic coating which has
an extremely low thermal conductivity. This is not a cheap option, but may be the
best choice where engine bay temperatures need to be reduced and there is insufficient
space for conventional exhaust lagging.
