Benefits of Galvanizing

Lowest First Cost

Galvanizing is lower in first cost than many other commonly specified protective coatings for steel. (The application cost of labour intensive coatings such as painting has risen far more than the cost of factory operations such as galvanizing.)

Less maintenance / Lowest long term cost.

Even in cases where the initial cost of galvanizing is higher than alternative coatings, galvanizing is almost invariably cheapest in the long term (because it lasts longer and needs less maintenance). And, maintenance causes problems and adds to costs when structures are located in remote areas, and when plant shutdown or disruption to production is involved.

Long Life

The life expectancy of galvanized coatings on typical structural members is far in excess of 50 years in most rural environments, and 20 to 25 years plus, even in severe urban and coastal exposure.

Reliability

Galvanizing is carried out to Australian / New Zealand Standard 4680, and standard, minimum coating thicknesses are applied. Coating life and performance are reliable and predictable.

Toughest Coating

A galvanized coating has a unique metallurgical structure which gives outstanding resistance to mechanical damage in transport, erection and service.

Automatic protection for damaged areas

Galvanized coatings corrode preferentially to steel, providing cathodic or sacrificial protection to small areas of steel exposed through damage. Unlike organic coatings, small damaged areas need no touch up.

Complete protection

Every part of a galvanized article is protected, even recesses, sharp corners and inaccessible areas. No coating applied to a structure or fabrication after completion can provide the same protection

Ease of inspection

Galvanized coatings are assessed readily by eye, and simple non-destructive thickness testing methods can be used. The galvanizing process is such that if coatings appear sound and continuous, they are sound and continuous.

Faster erection time

As galvanized steel members are received they are ready for use. No time is lost on-site in surface preparation, painting and inspection. When assembly of the structure is complete, it is immediately ready for use, or for the next construction stage.

A full protective coating can be applied in minutes

The galvanizing process is not dependent on weather conditions

Galvanizing is a Metallurgical Bond

Unlike paint coatings Hot Dip Galvanizing fuses zinc with the iron in the steel to form permanent layers. This microscopic view displays the typical transition layers.

One Advantage of Galvanizing is Sacrificial Corrosion Protection or Self Healing Small area end cutting or local damage to a hot dip galvanized item is usually protected due to the surrounding zinc becoming an anode for the exposed steel.

Technical Supporting Information

As a long time member of the Galvanizers Association of Australia we can assist you with access to key information from an extensive source of print and electronic data, publications and case studies

Design for Galvanizing

Design for Galvanizing Checklist

  • Are the vent and drain holes of sufficient size & quantity?
  • Are the vent and drain holes located properly? (One or more for draining and one or more for venting)
  • Are corners of gussets, stiffeners, and bracing cropped to allow free flow of zinc?
  • If the fabrication is comprised of steel of two or more thicknesses, is it designed to promote minimal change in camber/thickness?
  • Are welds overlapping surfaces seal welded?
  • Does the fabricator know to remove all weld flux and to use a weld material of suitable chemistry to produce a good zinc coating?
  • Have I accounted for marking/tracking of the parts through the galvanizing process and on to the job site?
  • Have I planned for tapping of nuts or threaded holes after galvanizing?

Vent and Drain Minimum Hole Sizes

  • Larger Holes Provide Significantly Improved Finish Quality
  • Locate Holes in Corners Diagonally Opposite to
  • Drain end or same Corner both ends if length above 8.4 metres)

Vent Openings = 25% Min.

Methods For Venting & Drainage

Hole Size Guide

Important – incorrect or missed holes can cause fatal explosion.
Please seek assistance and avoid cost for additional holes

Hot Dip Galvanizing Process

The galvanizing process used at Furphy Galvanizing produces a coating that conforms to Australian standards, AS/NZS 4680:2006 ‘hot dip galvanized (zinc) coatings on fabricated ferrous articles’. This process involves the following steps.