Pretreatment improves coatings of galvanized steel

Citation

(1999), "Pretreatment improves coatings of galvanized steel", Anti-Corrosion Methods and Materials, Vol. 46 No. 5. https://doi.org/10.1108/acmm.1999.12846ead.006

Pretreatment improves coatings of galvanized steel

Keywords Chemetall, Galvanising, Steel, Pre-treatment

Chemetall Ltd has introduced a new pretreatment system for electro and hot dip galvanized and alloy-galvanized steel to improve the performance of subsequent paint coatings and laminates. Known as Gardobond 4590, it claims to differ from orthodox pretreatment systems in that it is completely chrome-free and is based on an amorphous, complex oxide which converts the zinc or zinc alloy surface to a non-metallic coating. According to Chemetall, in conjunction with subsequent post-rinsing, this materially improves the performance of the subsequent coating.

Chemetall's Gardobond 4590 is applied by spray or immersion - plus a version which is available for strip-line application.

After the work is properly cleaned and water rinsed, it is sprayed or immersed in the Gardobond 4590 working solution for 60 to 120 seconds by spray, or two to five minutes by immersion, in the temperature range 40 to 55°C. In the case of Galvalume surfaces the temperature range will be 35 to 45°C. Exact conditions, which can vary according to the nature of the work being treated, can be advised by the Chemetall engineer, who will also supply the full operating instructions.

After the proper conversion coating is achieved, the work then proceeds to rinsing and further processing, usually with either Chemetall's Gardolene 60 or 6800.

Details available from Chemetall Ltd. Tel: +44 (0)1296 399233; Fax: +44 (0)1296 399211.