A lot of knowledge is also available concerning the
pre-treatment of the (metal) substrates, for example different
methods of increasing the adhering capability by
using grit blasting, grinding or etching. Chemical treatment
such as phosphating [7] is also used. Rubber will
not (normally) spontaneously adhere to the substrate so
that a durable bond is formed. Therefore one or two thin
layers (usually 7–20 µm) of a primer and an adhesive
have to be applied to the substrate in order to achieve
good adhesion. These are usually applied by spraying,
painting or dipping. Further details regarding substrate
pre-treatment and the application of the adhesives can be
found elsewhere [8].