ZINGA VS HDG

KEY CHARACTERISTICS OF ZINGA

ACTIVE CATHODIC PROTECTION

ZINGA® has the most important advantage that it offers a real cathodic (galvanic) protection. ZINGA® has a concentration of 96% special zinc in its dry layer which gives it it’s galvanic characteristics.

ZINGA® (also called “Zinganisation”) shows comparable protection as HDG.

Steel members which have been hot dip galvanized have proven cathodic protection by the sacrificial action of the the zinc on its surface. Damages to the HDG steel substrate show protection by the throwing power of the zinc layer.

EASY APPLICATION ON SITE

ZINGA® can be applied in the same way as paints, on site or in workshops.

Hot dip galvanization cannot be realized on site. The steel structures or beams have to be transported to and from the HDG plant. In case of repairs they have to be de-mounted or dismantled, transported to the HDG plant, hot dipped again, transported to the workplace or building site and re-mounted.

RELOADABLE/RECHARGEABLE

A cured ZINGA® layer, will reliquefy if a new layer of ZINGA®is applied on top of it. This ensures the creation of one homogenous ZINGA® layer with a continuous electrochemical contact between the Zinc particles, providing full galvanic protection. If the ZINGA® layer is very old, the Zinc salts on the surface (ensuring a passive protection), need to be removed to ensure cleanliness of the surface and complete reliquefication with the old ZINGA® layer; this can be obtained by performing a light sweep blast or a high pressure hot water washing.

Hot dipped structures can be hot dipped again but will require demounting or dismantling, blasted eventually and dipped into the Zinc bath. ZINGA®‘s mechanism of protection is so similar to conventional galvanizing that they work in complete unison, as they are merely different forms of zinc. Rather than replacing galvanized assets, structures can simply have their protection “re-charged” by applying ZINGA® to the rough surface of the old galvanizing after appropriate decontamination and removal of the salts.

OVERCOATABLE

ZINGA® can be overcoated with a fast drying, compatible paint. Care should be taken to avoid contamination of the Zinc layer by the use of aggressive solvents in the topcoat. The use of alkyd paints on top of ZINGA® is  to be avoided.

HDG requires specialized, compatible paints ; a thorough surface preparation is also needed before the application of a topcoat on HDG. This includes alkaline or acid rinsing and sweep blasting of the surface.

APPLICATION UNDER EXTREME CIRCUMSTANCES

ZINGA® can be applied in a wide variety of weather conditions. The ambient temperature should be between -15°C to +50°C with a maximum humidity of 95% as long as the dew point is 3°C above the steel temperature.

In comparison, this characteristic isn’t applicable for HDG. A HDG layer is applied in the hot dip plant.

UNLIMITED SHELF LIFE

ZINGA® has an unlimited shelf life. This means it is possible to always have ZINGA® in your inventory for touch up or for future projects. ZINGA® has a very long pot life. An opened ZINGA® can be re-used many days after having opened it (if  carefully closed). When opened, ZINGA® will not form a skin layer.

CONTACT WITH POTABLE WATER

ZINGA® does not contain toxic elements in its dry layer (after evaporation of the solvent). Therefore it can be, and has been, regularly used in contact with potable water. Since the ZINGA® remains active, it produces Zinc salts which dissolve in the water. This can sometimes lead to small precipitations in the water, which are however non-toxic. To avoid this, we recommend to do a water saturation with fresh water 12 hours after application of the ZINGA®. For more information, please contact the Zingametall Tech Team.

For HDG, Galvanizers that have submitted test coupons of their galvanized steel and have been approved by the NSF (National Science Foundation) have the authority to galvanize steel for use with potable water.

FLEXIBILITY OF COATING

ZINGA® containing 96 % of zinc remains a flexible layer, and resists to mechanical shocks by being compressed. There is no risk of disbonding (not even around the impact) within a multiple layer of ZINGA®. It will never show adhesion failures. Even on thin metal ZINGA® will keep its flexibility. An impact will simply push away and compress the zinc particles, not “breaking” the ZINGA® layer.

In contrast, when hot-dipped structures are bent over a certain angle, the coating could be damaged and the total structure will need to be hot-dipped again in order to restore the coating. It is recommended to use  a zinc rich liquid coating (like ZINGA®) In general, it is advised to bend the structures before hot-dipping. In practice, this is not always possible (e.g. pipes that need to be fitted to form connections).

SMALL BURN BACK ON WELDED STEEL

Zinganised steel can be welded without the release of any toxic fumes (tested according to BS 6853) and with a very small burn back. Since the ZINGA® is not in any way alloyed with the steel, there is no danger of zinc inclusion in the weld. Once the welding is finished, roughened and cleaned, a new ZINGA® layer over the welding will provide an all over protection.

For HDG structures it is recommended to weld before hot-dipping. If welded after hot-dipping, the zinc coating should be removed at least one to four cm from either side of the intended weld zone and on both sides of the steel part. Grinding is the most effective means of removing the galvanized coating.

NO RISK OF DEFORMATION

ZINGA® is applied under ambient temperature and there is no risk of deformation / distortion of the steel structures or members.

With hot-dip galvanization a risk of deformation of thin steel beams or members will need consideration. (due to the use of high temperatures of molten Zinc @ 450°C).