logo Matrix   home contact us
 
 

 

 

Spray Galvanasing


Spray Galvanising provides excellent protection in a wide variety of marine and industrial environments. The use of zinc coatings makes it possible to achieve fully effective, maintenance-free protection against corrosion and corrosion-enhanced mechanical failure of steel structures for more than 20 years. Forty year protection effectiveness has been documented in rural environments and more than 20 years in hard industrial, urban and coastal regions. Zinc performs better in alkaline conditions and is also a preferred metal for use in protection of steel in fresh and cold waters.

 

The British Standard Institution (BSI) Code of Practise in fact, specifies that only electrochemically active metal coatings will give protection of greater than 20 years to first maintenance for every type of environment considered and that in areas of immersed sea water or in sea water splash zones only sealed spray zinc or aluminium will give such protection. The corrosion tests of thermal sprayed coated steel carried our by the American Welding Society, as given in its 19-Year Report, confirm the remarkable effectiveness of sprayed zinc or aluminium coatings over long period of time in all sorts of hostile environments.

 

Better than Hot Dip Galvanising -

Cold process - there is no distortion on fabricated parts. Complicated structures like trusses, towers and bridge members can be given this treatment without fear of warpage.

Pure zinc coating - spraying assures a 99.95% pure zinc coating unlike in dipping where the initially pure bath gradually gets contaminated by iron. This iron can get deposited on the job and acts as a corrosion accelerator.

Any size or shape - unlike dipping, which is restricted by the size of the bath, in spraying there is no limit to the dimensions of the part to be coated.

Site jobs possible - spraying can be carried out at site, unlike in dipping, where the part has to be taken to the place where the zinc bath is available.

Ideal surface for painting - spraying leaves a rough surface which is excellent for painting. Dipped surfaces are smooth and paint, if applied, often peels off.

Wide range of coating thickness - coating thickness can be accurately controlled from a minimum of 50 microns to a millimetre, depending on the protection required.

Better surface preparation - Blasting, which is a prerequisite for spraying, removes all traces of oxides and exposes the base metal. Dipping, which is done after pickling, sometimes results in the link layer peeling off due to excess of acid or alkali.

Localized repair possible - On site repair can be carried out to damaged portions both at ground level and in erected condition

No hydrogen embrittlement - pickling, which is necessary for dipping, results in hydrogen liberation. This gas can get entrapped between the steel and the zinc causing embrittlement and making it unsafe for working loads.

Dross embedment avoided - in dipping, dross, which is present at the top of the molten zinc bath, gets embedded between the iron and zinc resulting in peeling of the coating.

Excellent high friction grip - spraying maintains the efficiency of friction grip bolts and ensures their effectiveness throughout the life of the structure

 

Contact us to Fight Corrosion!