OR TANK COATINGS - THE CRITICAL DIFFERENCE -
"Wynboer" magazine Nov '03
In the wine industry tanks are exposed to chemical attack from the
acid and alcohol present in the wine making process. This causes
severe corrosion and erosion, which leads to product contamination
and, eventually, to tank failure.
these negative effects, preventative measures are taken, usually
in the form of a coating or lining. The intention is to emulate
the qualities of glass which is inert, chemically resistant, free
of odour and taste, with a tough smooth surface that prevents retention
of potentially harmful substances, as well as being is easy to clean
difference between coatings and linings……..
A coating is
no more than a layer of paint applied with a brush, roller or spray
gun, at room temperature. It is rarely applied at more than 120
microns thick per coat, because this is typically the specified
thickness for this type of coating. A coating often contains a solvent,
which must evaporate, leaving microscopic voids in the film layers.
These voids eventually link up to create a cavity (pin-hole), exposing
the tank surface to the product. There are no known coatings that
have withstood more than 10 year's continuous exposure to alcohol
concentrations above 12%.
the other hand, are solvent free, more than 600 microns thick and
have all the good qualities of glass.
is the leading product of this kind. After a high-pressure dry or
wet (dust-free) cleaning process, Munkadur® is sprayed onto
the host surface at 86° C at 250-bar pressure. This results in a
seamless lining of between 800 and 1000 microns thick. Consisting
entirely of solids, there is no solvent evaporation during the curing
process and it has a high-gloss, hygienic surface that is easy to
clean and maintain as well as having better impact resistance.
with Munkadur® shortly after its 1966 release are still functioning
perfectly, 37 years later. Apart from the absolute peace of mind
that such a product brings, one must consider the financial benefits,
to say nothing of the inconvenience of having to re-coat tanks every
five to ten years. In the medium to long term, savings in the
region of 700% can be realised.
Emplast is the
sole southern African licensee for Munkadur®. For technical
details and other information about this essential process contact
SCOURGE OF GRAFFITI - EMPLAST TO THE RESCUE
When a national monument was attacked by graffiti vandals, Emplast
reversed a disastrous situation and restored the structure as a
gift to the nation.
become the scourge of modern day suburbia. Apart from an ego boost
for an offending vandal, it serves no purpose but to deface private
property and damage beautifully maintained buildings.
afterwards is a problem. If handled incorrectly it can result in
A classic example
is the Rhodes Memorial on Devil's Peak in Cape Town. When this structure
was vandalised, the problem was particularly acute. The bronze bust
of Cecil John Rhodes and the surrounding masonry was defaced with
bright red paint. As the centre piece of the memorial, the bust
is flanked by huge bronzes of lions and the statue of Physical Energy.
off bronze would only take a bottle of thinners. But the memorial
was erected in 1912. The bronzes have been gathering a much valued
patina for the best part of a century. Bathing Cecil Rhodes in anything
that would remove oil based paint would also destroy the delicate
patina and throw the bust into contrast with all the other statues
The stone work
behind the bust posed another problem. Painting over the red paint
was not an option and cleaning only the painted areas would result
in unacceptable colour variation.
the best solution.
This state of the art equipment has an infinite range of dry or
wet cleaning abilities. Using any abrasive from steel shot, through
to bicarbonate of soda, it can blast thick residue off tanks and
achieve a 150µm profile on steel, or it can delicately lift coatings
only microns thick without harming the original surface.
to restore the damaged monument as a contribution to the curators
of the site and to the South African nation.
Using the Jet Stripper,
Emplast returned the Rhodes Memorial to its former glory without damaging
the patina on the bronze, or leaving any trace of the cleaning operation
on the masonry.