| The
advantages of natural mineral over its synthetic rival stretch
way beyond environmental issues. Of course the fact that natural
is simply taken out the ground while synthetic is made through a
series of highly toxic procedures, is clearly a significant
point to consider in this environmentally conscious era.
However, when it comes to manufacturing paint primers, there are
many more highly significant reasons that favour Natural Red
Oxide ahead of its synthetic rival.
Here are
some popular myths:
* The higher Fe2O3
of synthetic (say 98%) offers better protection to its natural
rival (80-82%).
Wrong,
higher Fe2O3 content does not mean superior
protection. Tests show that a well chosen natural oxide will
perform better than the overwhelming majority of synthetics.
*Colour is important; it is
essential have the right shade.
Wrong,
the popular view that a bright oxide looks better and therefore
offers better protection, is a myth. Research shows that the
opposite is often true. The truth is that in terms of protection;
colour is of no importance whatsoever.
* Although synthetic minerals
often have three times more soluble salts, since it is usually
no more than 1%, it isn’t significant.
Wrong, while soluble salts in
Natural Red Oxide, through careful mineral selection can be kept
well below the critical 0.4% barrier: some synthetics contain
levels of chlorides and sulphates that far from protecting,
accelerate the corrosion process. Synthetics build up a high
level of soluble salts during the production process. A large
proportion of these can be removed by washing. However, the
removal of the final traces is not practical. The remaining
salts: Calcium and Iron Chlorides Sodium and Iron Sulphates can
seriously compromise the protective qualities of the paint.
* Difference in oil absorption
– natural is rated at between 10-14 and synthetic
17-25 – is not significant.
Wrong, since a high
concentration of well dispersed pigment will increase the
barrier characteristics, it follows that an oxide with a lower
absorption should provide better protection than one with a high
absorption.
* There is no difference in
quality between natural and synthetic in cement products.
Wrong, roofing tiles and bricks incorporating synthetic pigment
fade in the sun, quickly leaving them looking pale and washed
out. As the evidence of the cave drawings of 12,000 years ago
underline - natural red oxide suffers from no such problems, and
stands the test of time. |
