Brown, structured surface shows a uniform texture, appears wooden, without visible details or text in a simple, monochromatic context.

STEEL HOT-DIP GALVANIZED as material

Hot-dip galvanized steel as material

for purely technical surfaces

During hot-dip galvanizing, the steel base material is immersed in a molten zinc bath (approx. 450°C). After dripping off, a more or less thin zinc layer remains as a coating. This forms both active and passive corrosion protection: the thin layer protects the base metal from moisture (passive) and also acts as a sacrificial anode (active). The steel underneath the zinc coating is protected from corrosion until the zinc is completely consumed. The zinc coating is bright shiny when fresh. Over time, it forms a patina as a result of corrosion, making the appearance darker and more matte.

Several curved seating steps made of concrete and wood rest side by side, surrounded by green hedges and trees, next to a paved footpath in a park.

Perfectly shaped planning: curved step landings made of hot-dip galvanized steel in a schoolyard.

Everything important at a glance:

STEEL hot-dip galvanized

User information METAL Tender for basic material

Color coating for hot-dip galvanized objects?

Hot-dip galvanized objects can also be coated with paint. To ensure that the paint adheres well, an adhesion improver (primer) is usually applied beforehand. However, whether the adhesion primer was actually applied to the complete hot-dip galvanized surface is difficult to check after paint coating and often only becomes apparent after years due to rust spots. We therefore recommend that garden objects that are to be color-coated be made of the corrosion-resistant base material stainless steel (V2A). This may not be the cheapest option, but it is certainly the most durable.

Environmental aspects speak in favor of hot-dip galvanizing

Corrosion protection by hot-dip galvanizing is resource-saving and sustainable. In direct comparison with other processes, a large amount of CO2is saved.

Powder coating or painting?

When it comes to color coating, the question quickly arises as to the best technical process: powder coating or painting? Powder coating is cheaper, more uniform in appearance and more stable in coating. The disadvantage is that defects cannot be repaired (filled) in the base material, and scratches, chipped paint on edges and other defects can hardly be repaired to a high standard on site. Therefore, we recommend painting large-scale, permanently installed garden objects. Painted elements can be filled and scratches can be easily repaired on site. Unfortunately, painting is up to 30% more expensive than powder coating. However, the extra cost is usually worth it, as customer satisfaction is much higher with painted objects in the garden.

Red flowers bloom in a bed, surrounded by a red border. In the background, a large yellow cylinder shines, exposed to bright daylight.

Lackieren statt pulverbeschichten ist meist die bessere Wahl, was Wartungsfreundlichkeit und Lebensdauer anbelangt.

Caution with flat, hot-dip galvanized parts

Flat sheet metal components are only suitable for hot-dip galvanizing if the aim is pure corrosion protection and no requirements are placed on the appearance of the surface and the tolerances. During hot-dip galvanizing, the process-related heat input always causes distortion and large-scale dents and deformations in flat parts. We therefore advise quality-conscious builders and architects against hot-dip galvanizing and, if necessary, subsequent color coating of sheet metal components. The permissible tolerances in the technically authoritative regulation DIN EN ISO 1461 are much greater than is usually assumed. For this reason, we at Gartenmetall always supply large-format color-coated objects made of the high-quality base material stainless steel, which is then painted. We have made the experience that this is the only way we can meet our own high requirements and the customers' expectations regarding quality and component accuracy.

Large grey planter with ornamental grasses stands on wooden terrace next to black wicker furniture. In the background, pebbles and a light brick wall can be seen.

Großflächige Metallobjekte für den Garten werden besser aus dem Grundmaterial Edelstahl hergestellt und dann farbbeschichtet, da hier kein Verzug entsteht.

Layer thickness according to ISO standard

All our hot-dip galvanized gardenobjects are treated according to the requirements of DIN EN ISO 1461. This guarantees a minimum coating thickness of 55 μm for material thicknesses between 3 mm and 6 mm, and even a coating thickness of 70 μm for sheet thicknesses greater than 6 mm. At these thicknesses, a service life of more than 50 years can be achieved - depending on the ambient conditions - due to the passive and active protective effect of the zinc coating without maintenance.

Umweltaspekte sprechen fürs Feuerverzinken

Korrosionsschutz durch Feuerverzinken ist ressourcenschonend und nachhaltig. Im direkten Vergleich zu anderen Verfahren wird eine große Menge CO2 eingespart.

A bicycle stands at a modern metal bike rack outdoors, surrounded by blurred vegetation and buildings in the background. The bicycle is branded with the inscription 'CMTB 2000'.

Bicycle parker OLDENBURG made of hot-dip galvanized steel

Problem: White rust on hot-dip galvanized surfaces

White rust is the name for streaky corrosion on the hot-dip galvanized surface. White rust has no effect on weather resistance, but makes the garden object unsightly. To reduce white rust, many hot-dip galvanizers offer additional protective coatings for the hot-dip galvanized surface. However, this is relatively expensive and is not really necessary if the freshly galvanized objects are properly treated and stored. Therefore, an additional protective coating is not standard and may have to be agreed upon and ordered separately.

A grey wall shows dirt marks and a bright, curved line, surrounded by a dark, tar-like surface in the background.

Undesirable side effect: white rust on hot-dip galvanized surface

Tender text for GaLaBau, for landscape architects and planners

"Flat steel rolled with corrosion protection by hot-dip galvanizing (piece galvanizing) according to DIN EN ISO 1461: 2009-10." For load-bearing, hot-dip galvanized metal and steel components in the area regulated by the building authorities, DASt Guideline 022 "Hot-dip galvanizing of load-bearing steel components" must also be applied. There is no need to specify the thickness of the zinc coating separately, as this is regulated in DIN EN ISO 1461.