Sometimes the galvanized coating is shiny and sometimes it’s dull grey why is that?
Galvanizing is not just a coating, it’s an alloy of the steel and zinc. The appearance of the coating is dependant on a number of factors such as the chemistry and thickness of the steel and the immersion time in the molten zinc. There’s no difference in the corrosion protection of a shiny finish versus a dull finish.
My galvanizing has brown staining – is it rusting?
When two surfaces are welded together and either left open on one edge or the weld is not fully sealed, it’s common to find what looks like rust seeping out of the joint. It’s small remnants of trapped acid and is usually noticeable after the first rain post galvanizing. It’s harmless but unattractive and can be cleaned off with a stiff brush and water.
I have made alterations to my galvanized item. How do I protect the area where the galvanizing has been damaged?
The galvanizing standard, ISO 1461, allows for small repairs, say the size of a 50p, to be protected with the use of zinc rich paint. The area should be rubbed down with sandpaper and then 2/3 layers of paint should be applied ensuring a dry depth of 100 microns is achieved. For larger sections the material should be stripped back to bare steel and re-galvanized.