The most effective protection is the so called cathodic protection, because its action is based on the electrochemical interaction between the applied surface layer of zinc (anode) and base metal (the cathode). The presence of free electrons at the zinc prevent corrosion of the iron, because they react with oxygen.
The main disadvantage of this method, however, is the technological difficulties in applying the coating - one should use baths for complete immersion of the details, which in practice is only possible at the time and place of their production.
Opportunities for corrosion protection of ferrous metals, however, were radically changed with the creation of a method for cold galvanizing.
Broadly speaking, the cold galvanizing combines the advantages of two existing methods - the quality and durability of protection equivalent to hot dip galvanizing and the easy application as in ordinary paints and varnishes - with a gun or brush directly to where the relevant structure or facility are installed.
Zinc-silicate primer or ZSP contains a high content of zinc with purity 99.995%, and this indicator covers those early requirements for effective protection.
Excellent qualities and opportunities for corrosion protection of the new method makes the spectrum of its application extremely wide - virtually anywhere where there are constructions of ferrous metals: from the various bridges, ports, railways and other transport facilities in all kinds of metal structures, energy and other installations and pipelines, containers and tanks to typical household applications - protection of gutters and other flashings on the roof, balcony railings, fence construction, etc.
Zinc silicate primer - ZSP is widely used by major manufacturers to protect their vehicles against corrosion - Chrysler, Mercedes, Porsche and others protect nearly 90% of the cars in this way.
Zinc silicate primer - ZSP is equally applicable to protect new structures and facilities, and the renewal of (ie repair) of existing.
Moreover, successful coating of zinc silicate primer - ZSP is possible when treated surface is not completely dry.
The zinc silicate primer - ZSP can be used as an only layer, ie only coverage or the applied cold "galvanizing" or to serve as a basis stable primer before application of top compatible decorative coating of organic, synthetic latex, rubber, epoxy and other coatings.
In cold galvanizing local mechanical damage also not violate the overall protection and do not cause progressive destruction of the corrosion layer.
Extremely effective is the application of zinc silicate primer - ZSP on old hot-dip galvanized items, with a protective coating which not only updated but its durability and repeatedly extended. In this case, the surface should be clean and degrease with suitable solvents and industrial methods.
Zinc silicate primer - ZSP comes in cans and boxes, as most traditional paints and varnishes, and applied like them - with a brush, paint roller (rolling) or with a spray gun.
With an average thickness of the zinc coating 75 microns the material consumption is about 250- 300g / m2.