The paint system specifically designed to give perfect adhesion to galvanized steel.
It’s no surprise that hot dip galvanizing is the finish of choice for industries as diverse as manufacturing, engineering, and construction. But, it has previously thrown up practical issues when the steel needs to be painted to provide an aesthetically-pleasing end result.
Trevor Beech of Wedge Group Galvanizing explains common problems with products traditionally used to coat galvanized steel, and how a new specially developed paint will put these problems firmly in the past.
“For the vast majority of steel-related projects, hot-dip galvanizing is the most effective method to provide long-lasting protection against rust and corrosion. Because it forms a series of alloy layers with the steel, it is much more robust than other coatings that only bond chemically or mechanically, and also has the added advantage of fully coating the steel, both inside and out.
Once steelwork has been galvanized, there are occasions when colour needs to be added to either complement a company’s branding, or perhaps to create a greater visual impact. The biggest challenge in adding colour to galvanized steel is achieving proper adhesion.
Standard paints aren’t designed for use on ferrous metals which often means that when used, the paint doesn’t bond adequately to the galvanized surface, and consequently peels or flakes prematurely – an end result that leaves an aesthetically poor finish, not to mention the time and effort required to repaint the steel.
However, there is a solution; Galvacoat®, is a one-coat, two component polyurethane-based paint which has been specifically designed for use on galvanized steel and so eliminates the requirement for any special etch primers, while it gives GT0 adhesion for the entire duration of its coating.
GT0 adhesion is the British Standards test method for adhesion classified GT0 (BS 3900 Part 6 on galvanized steel). It also has excellent resistance to UV exposure, and is suitable to be applied as a topcoat in outside weathering conditions.
The paint is available in all RAL and BS colours at different levels of gloss, allowing the end contractor a huge degree of design freedom, but just as importantly, galvanizing provides an ideal primer for it. Galvacoat® is applied by brush, or by air or airless spray, to a surface that is free of dust, rust, oil, grease and soluble salts, while for zinc surfaces, a combination of degreasing or steam cleaning is advised to ensure maximum effectiveness.
For use in areas of low industrial output, a dry film thickness of 80 microns can last for a minimum of 8-10 years, while a thicker coating can lead to similar results even when used in particularly heavy industries or coastal areas where high amounts of chemicals or salts can attack the coating. This drastically reduces, or eliminates completely, the need for repeated on-site maintenance and replacement costs.
Wedge Group Galvanizing is the sole distributor in the UK for Galvacoat®, for more information visit the website http://www.wedge-galv.co.uk/Galvacoat.aspx