Treating steel with hot dip galvanising
Hot dip galvanising is a chemical treatment for steel that creates a toughened, long-lasting and corrosion-resistant coating.
Steel is put through a chemical wash to remove all rust, oil and mill scale from the surface before being dipped into a bath of molten zinc heated to around 450°C (860°F). After cooling in a quench tank, the zinc coating is then metallurgically bonded to the steel and is ready for use.
There are many reasons why hot dip galvanising is recommended in external steel-based fixtures; here are our top ten:
- Long life
Steel that is properly galvanised can remain useable for more than 70 years in many circumstances.
- Competitive initial cost
Hot dip galvanising is a low-cost and low-risk process compared to many other available coatings. This is because while many other treatments, such as painting, are labour intensive, galvanising is a highly automated manufacturing that is well-regulated across the UK and Europe as well as globally.
- Lowest lifetime cost
Galvanising is the most adaptable and cost-effective approach to protect steel for lengthy periods. It can extend the lifespan of a product whilst needing minimal maintenance, which is particularly when installations are in hard-to-reach environments such as isolated regions, in rough terrain or where there are safety constraints that limit access.
- Reliability
The galvanising process is simple and uncomplicated which leads to reliable and consistent results. Unlike a paint coating, the metallurgical bond established by galvanising becomes a permanent component of the steel rather than being limited to a chemical or mechanical bond. As part of the automated process, the coating thickness, or weight, can be easily defined with no future reapplication required.
- Speed of application
A complete protective coating can be applied in a matter of hours, compared to other processes that can take in excess of 7 days. This means that products can be made available to meet even the most demanding timelines, all with an exceptional finished result.
- Coating toughness
Galvanising has up to 10 times the abrasion resistance of organic paint coats. The hot dip method results in a coating that is metallurgically attached to the steel, giving it by far the best resistance to mechanical damage during handling, storage, transit, and building.
- Complete coverage
Because the process involves dipping entire lengths of steel in molten zinc, it coats the whole surface of the steel including uneven angles and small gaps that could otherwise be difficult to treat. Rather than thinning off, the coating tends to build up at critical corners and edges, providing essential additional coverage in areas prone to wear and tear.
- Intelligent protection
Galvanised steel not only weathers slowly, reducing the need to maintain and/or replace, but the coating also corrodes preferentially to safeguard any tiny sections of steel exposed by drilling, cutting, or unintentional damage with cathodic protection. If a larger area of damage occurs, the cathodic protection stops rust from creeping sideways and causing further damage.
- Ease of inspection
As a result of its simplicity, steel that has been hot dip galvanised is easy to inspect; simple visual checks to ensure the coating appears continuous are enough to validate that it remains fit for purpose. Thickness, as stated by EN ISO 1461, can be easily tested with an electronic probe.
- Faster construction
Once treated, galvanised steel is ready to be used with no further surface preparation, painting or inspection required.
If you’d like to discuss the various treatments we offer, including hot dip galvanising, for your future projects then please get in touch. You can reach our team of experts by calling +44 (0) 1484 401610 or email here.
