Powder coating is an environmentally friendly way of applying a conservation layer. Using compressed air, a negatively charged powder is coated onto a positively charged product. Through the electrostatic principle, the powder will stick to the coated object. This technique is primarily used to create a finish that is harder than normal paint.
Electro-galvanising is a (galvanic) procedure in which a thin yet strong layer of zinc is applied through electrolysis. The electrolysis takes place in special chemical baths and in ‘drums’. This way, products are protected against corrosion and rust. However, there is another reason to choose for this technique. The electrolytic surface treatment provides products with a beautiful ‘glossy-smooth’ appearance.
The best way to protect steel from rusting is thermal galvanisation. Another name for thermal galvanisation is hot-dip galvanisation. In this process, the complete steel product, after several pre-treatment baths, is dipped into a large basin of molten zinc. Alloy layers will form around the product. These are much thicker than the zinc layer that is applied through e.g. electro-galvanising.
The thicker zinc layer resulting from thermal galvanisation does require finishing in case of screw thread. In addition, there is a higher risk of deformation.
The passivation of stainless steel takes place through a treatment in a bath of nitric acid, restoring the passive condition through the restoration of a layer of chromium oxide. Through this treatment, the metal below will regain its original corrosion resistance.
Electropolishing is an electrochemical process in which material is removed from a metal product. It is used to polish surfaces (make them smoother).