ZINCALUME® steel and galvanised products have very similar working characteristics. Since they are materials that are industrial in nature, it is important to be aware of their few characteristics. Below are some helpful information regarding Zincalume steel.
Protection
At the cut edge, ZINCALUME® steel provides similar protection to galvanised coatings. The zinc or aluminium alloy coating of ZINCALUME® steel provides galvanic protection to bare steel exposed at cut edges and by deep scratches.
Surface Passivation
Surface passivation enhances the protection of the galvanised and ZINCALUME® steel product during storage, forming, handling and fixing. It largely eliminates the need for rollforming oils, offers improved wet stack corrosion resistance and generally makes the product more mark resistant during handling and fixing.
Handling and Storage
The normal storage care, site cleanliness and installation procedures used for GALVSTEEL® products apply to ZINCALUME® steel products. Although passivation provides improved protection during storage, care should still be taken. If ZINCALUME® steel becomes wet during storage, the product should be immediately separated, wiped with a clean cloth and placed in a position where it can completely air dry.
Formation
As with GALVSTEEL®, ZINCALUME® steel is suitable for all but the most severe forming operations. With ZINCALUME® steel, the passivation system acts as a dry lubricant and in most cases will eliminate the need for additional lubrication in most forming operations. Solvent-based lubricants must not be used.
Welding
ZINCALUME® steel can be satisfactorily welded using the following techniques: GMA (Gas Metal-Arc, often called MIG), Resistance welding (spot or seam) and MMA (Manual Metal-Arc). When welding ZINCALUME® steel, excessive weld currents must be avoided. With correct welding procedures, sufficient coating is normally left on the ZINCALUME® steel sheet to protect the substrate from corrosion. Weld repair should be carried out by coating with a zinc-rich paint. Adequate ventilation must be provided even though the welding of ZINCALUME® steel gives off fewer fumes than galvanised steel.
Joining and Sealing
ZINCALUME® steel cannot be soldered. Join ZINCALUME® steel in the same way as recommended for COLORSTEEL® prepainted steel products. Use a neutral cure silicone sealant in conjunction with mechanical fasteners such as blind rivets. Care should be exercised in the choice of rivets. Aluminium rivets are recommended. Monel, stainless steel and carbon steel rivets must not be used.
Fasteners
Most fasteners complying with the corrosion requirements of Australian Standard AS3566 “Screws – Self-drilling for the building and construction industry” are suitable for use with ZINCALUME® steel. Stainless steel fasteners should not be used with ZINCALUME® steel or COLORSTEEL® prepainted steel products in any environment. Aside from that, lead headed nails must not be used and you should use only low carbon (< 15%) non–conductive sealing washers.