*With special / selected paints **Authorisation depends on local legislation *** For HDG, thin steel structures / members need consideration before hot dipping

ZINGA®

HDG

Active cathodic protection

ZINGA® offers a cathodic protection throughout the layer, comparable to the protection of hot dip galvanising. ZINGA® has an overall concentration of 96% atomized zinc in its dry layer which provides galvanic protection and with sacrificial properties. ZINGA® has an excellent throwing power (no undercreep corrosion).

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.

For more information see “How does it work?

Easy application on site

ZINGA® can be applied everywhere under normal conditions, regardless of temperature and humidity (95% RH). It does require some training but not highly qualified painters.

HDG requires transportation of the steel structures or beams to and from the HDG plant. Skilled galvanisers must prepare and dip the structures.

For more information see “Application

Reloadable

ZINGA® is a reversible coating. A fully dried ZINGA® layer will re-liquidise upon contact with a new layer of ZINGA®, even after 20 years. This ensures the creation of 1 homogeonous ZINGA® layer with a continuous electrochemical contact between the zinc particles and thus providing 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 complete reliquefying: this can be obtained by performing a light sweep blast or a high pressure hot water washing.

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

For more information see “Characteristics / advantages” and “Application

Overcoatable

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

HDG requires compatible paints and a good 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.

For more information see “Overcoating of ZINGA

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% so long as the dew point is 3°C above the steel temperature.

Not applicable. A HDG layer is applied in the hot dip plant.

Unlimited shelf life

ZINGA® has unlimited shelf life. This means it is possible to always have ZINGA® in storage for touch up or for future projects.

Not applicable.

Contact with potable water

ZINGA® only contains non-toxic elements in its dry layer (after evaporation of the solvent). Therefore it can be, and has been, 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 wash the surface very thoroughly with fresh water 12 hours after application of the ZINGA® . For more information, contact a Zingametall representative.

The American Water Works Association (AWWA) allows the use of galvanized steel for water storage tanks. Only galvanizers that have submitted test coupons of their galvanized steel and have been approved by the NSF have the authority to galvanize steel for use with potable water.

Flexible layer

ZINGA®, containing 96% Zinc in the dry layer has very few binder. In fact, not every Zinc particle is completely surrounded by resin. This also explains why the ZINGA® layer is rough and porous. However, this is why ZINGA® behaves like a metal when it comes to impact and bending. ZINGA® can be bent over very small angles without showing cracks in the dry layer.

When hotdipped structures are bent over a certain angle, the coating could be damaged and the total structure might need to be hot-dipped again in order to restore the zinc layer. Repairs of HDG are ideally done with ZINGA®.

Welding on coated steel

Zinganised® steel can be welded without the release of any toxic fumes (tested according 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 inches from either side of the intended weld zone and on both sides of the steel part. Grinding is one of the means of removing the galvanized coating.

Structure keeps its form during application

ZINGA® is applied under ambient temperature and does not deform the structure.

With hot-dip galvanisation, deformation of the structure is possible due to the use of high temperatures of molten Zinc. There is also potential for hydrogen embrittlement within welds. This can lead to problems when structures are precisely measured in a steel structure to form connections.

ZINGA vs paint
COMPARISON
Application