PHYSICAL & CHEMICAL PROPERTIES
ZINGA is a one component Film Galvanising System containing 96% zinc (dust) in its dry film. It is a metallic coating and not a paint. The purity of the zinc used is so high that dry ZINGA does not contain any toxic elements.
2,67 kg/dm. at 15ºC
80% in weight, 58% in volume (ASTM D2697) 96% zinc, purity 99,995%
From -40ºC to +150ºC
THEORETICAL SPREAD RATE:
3,62 m./kg for 60 μm DFT
≥40ºC - 60ºC
ACTIVE AND PASSIVE PROTECTION
ACTIVE GALVANIC PROTECTION
The zinc in ZINGA (anode) sacrifices itself, protecting the steel beneath in a comparable and even better way than hot-dip galvanising.
Upon impact, the electron flow resulting from a potential difference between the zinc and steel will prevent the steel from corroding.
PASSIVE BARRIER PROTECTION
As the ZINGA oxidises, a layer of zinc salts slowly builds up on the ZINGA surface, closing the film and enhancing the barrier effect of the coating. Next to this, a supplementary barrier protection is provided by the binder in ZINGA. The binder reduces the depletion of the zinc, providing a long lasting active protection.
HOW TO USE ZINGA
STAND ALONE SYSTEM
ZINGA provides comparable protection to conventional galvanising without the need for topcoats. Although ZINGA is only available in grey (the natural colour of zinc), the significant advantage of this form of application is that the ZINGA layer can be re-coated at any point in the future with the bare minimum of preparation and without compromising the integrity of the coating (see Re-charging of ZINGA). ZINGA on its own is often used, because the structure is already on site or too big for the molten zinc baths.
For optimal protection, ZINGA should be applied in two layers of 60 or 90 μm DFT each.
AS SHOP PRIMER
At a thickness of 30-40 μm, ZINGA can be used as a shop primer. The big benefit is found in the fact that the steel structures do not require re-blasting before coating if ZINGA is applied as a shop primer. The steel structure can be further coated with ZINGA to obtain a cathodic protection or with any other paint without the need for re-blasting! Zinganised steel structures can be welded and bent during assembly.
AS A PRIMER WITH SUITABLE TOPCOATS
Not everybody likes the colour grey and with the additional protection of a compatible topcoat the coating durability offered significantly increases. ZINGA does not even have to start actively working until the topcoat has been compromised and with no underlying corrosion creep or rust bubbling, the topcoat itself inevitably lasts longer. In a duplex system (Active + Passive), ZINGA should be applied in 1 layer of 60 to 80 μm DFT.
REPAIR FOR WORN OR DAMAGED HOT-DIP GALVANISING OR HOT METAL SPRAY
This is probably the most common use of ZINGA as it requires the simplest surface preparation. ZINGA's mechanism of protection is so similar to conventional galvanising that they work in complete unison, as they are merely different forms of zinc protection. Rather than replacing galvanised assets, structures can simply have their protection "re-charged" by applying ZINGA to the rough surface of the old galvanising after appropriate decontamination and removal of the salts.
Widely used in countries where the available concrete can be of lower quality, Zinganising the steel rebars before assembly and immersion in concrete ensures vastly increased protection from corrosion without reducing the pull-out strength of the bars. Recent tests in three independent laboratories showed that ZINGA had at least twice the corrosion protection of either galvanised or epoxy coated rebars.
HOW TO APPLY ZINGA
Once thoroughly mixed, ZINGA can be applied by using a normal paintbrush, a short-fibre roller (not for the first coat), or a conventional or airless spray-gun. When applying ZINGA by spraying it must only be thinned with Zingasolv. ZINGA can be applied in a wide variety of weather conditions. The application surface temperature range is from -15 ºC to +40 ºC, where conditions allow with a maximum humidity of 95% so long as the steel temperature is 3 ºC above the dew point. Like all coatings the substrate surface should be free from all types of contamination.
PREPARATION OF THE SURFACE
NEW METAL SURFACES
Steam-clean or high-pressure wash-down all surfaces, followed by a grit or slurry blast to SA 2.5 to obtain a roughness degree Rz 50 to 70.
OLD, PREVIOUSLY GALVANISED, PAINTED AND/ OR RUSTY SURFACES
Steam-clean or similar to remove all contamination from porous surfaces. Allow to dry off and blast-clean as normal.
GALVANISED AND ZINGANISED STEEL IN (FAIRLY) GOOD CONDITION
Steam-clean the surface, followed by a light sweep blast to remove the zinc salt layer.
ZINGA is touch dry and dust-free in about 10 minutes at 20ºC (40 μm DFT).
It can be over coated with a new layer of ZINGA 1 hour after touch dry. ZINGA with a compatible topcoat can be over-coated with a compatible paint after 6 to 24 hours, depending on drying conditions. To overcoat ZINGA, use a mist/full coat technique.
Another of ZINGA's unique characteristics is its ability to re-liquidise when a new coat of ZINGA is applied onto an existing ZINGA layer, to form a single homogeneous layer. This ensures a massive cost saving in ongoing maintenance, because the old ZINGA layer does not need to be removed before re-coating with a new ZINGA layer (a removal of contaminants is required though).