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Adhesion
The vastly superior performance of Si-COAT is directly attributable
to the fact that Si-COAT was developed from first principles
to act as an anti-corrosion coating that takes advantage of
metal in its natural state.
 Most
metals when left to weather in the environment will tend toward
an oxidized state. Because of the intolerance of conventional
coatings to this oxidized surface and their poor adhesion
characteristics, abrasive blasting has become a widely accepted
aspect when high-performing corrosion protection is required.
In developing Si-COAT, the chemists and engineers at CSL
set out to debunk the myth that abrasive blasting is needed
for long-term, high-performing corrosion protection. To do
so, they started with a model of the metal substrate in its
natural, oxidized state. Metals that have been blasted to
commercial, white or near-white conditions are in an unnatural
state, and when left to weather will again form the oxide
layer removed by abrasive blasting.
 Conventional
coatings such as epoxies employ a very weak type of bond.
Broadly speaking, this type of bond can be classified as a
secondary valence attraction. The bond Si-COAT forms with
the substrate takes advantage of the oxidized metal and forms
a vastly stronger bond, which is classified as a primary valence
attraction. Secondary valence attractions are not only much
weaker than primary valence attractions, but they are reversible
over time. Primary valence attractions are non-reversible,
and those formed by Si-COAT are so exceptionally strong, they
are unaffected by the ravages of ultraviolet (UV) radiation.
The chemistry of Si-COAT was also developed so that the
bonds formed between coating and substrate are far more numerous
than those formed by conventional coatings. This is achieved
by improving the wetting characteristics of the coating to
the point that the coating so closely hugs the microscopic
imperfections in the metal that adhesive bonds cannot help
but form.
 To
form a bond between coating and substrate (be it either a
primary valence attraction as in Si-COAT or a secondary valence
attraction) the coating needs to get within 10 Angstroms (3
times the diameter of an oxygen atom) of the substrate. Conventional
coatings have great difficulty in closing this gap between
coating and substrate and so fewer bonds are actually formed.
To overcome this, profiling of the metal substrate is often
employed in application of conventional coatings. The act
of profiling a metal essentially deepens the microscopic crevices
in the surface, hence increasing the surface available to
the conventional coating for bonding. This is simply a method
by which to increase the statistical probability that the
conventional coating should form bonds with the substrate.
The net result of Si-COAT, which was engineered specifically
to take advantage of metals in their natural oxidized state,
is a product that eliminates the need for abrasive blasting
and/or profiling. The graphs below show the dramatic difference
in the strength of the Si-COAT bonds to the metal substrate
and superiority of its adhesion.
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