Procedure after galvanizing
Zinc layers prior to being exposed to weather conditions are sensitive to humidity if access to fresh air is limited. This situation refers mostly to newly covered zinc coatings which just after galvanizing are characterized by high chemical reactivity. Therefore, white corrosion appears relatively quickly. This phenomenon also occurs in case of rain water which cannot flow down on the zinc coating.
To prevent white corrosion, it is advisable to store galvanized constructions properly (also in transport) to enable free flow of air. Therefore, it is recommended to separate galvanized elements with spacers. Zinc-coated articles are best stored under the roof, far from materials creating aggressive enviornment (fertilizers, acids etc.).
While storing and fitting elements, it is vital to avoid sources of rust. Galvanized constructions should not be additionally mechanically treated (cutting, drilling, sanding etc.) because the anti-corrosion layer may be damaged. Leaving rusty places unprotected will result in further new sources of corrosion and faster use of protective zinc coating.
To guarantee simultanuous anti-corrosion protection, it is essential to join hot-dip galvanized elements only with other hot-dip galvanized articles. Joining elements (screws, rivets) protected in a way different than hot-dip galvainized (e.g. galvanically) due to a thinner zinc layer are not suitable for external weather conditions.