Trailer and caravan parts are made in a variety of metals; aluminium, stainless steel and cast steel and iron. Cast steel and iron parts that need extra protection from salt corrosion are either hot galvanised or dacromet coated, both are Zinc coatings. 

Dacromet and Zinc-flake

Dacromet is a brand name with a patented "zinc flake" application. Sometimes this brand name is loosely used to describe Zinc rich coatings. Cold galvanising is another term. Dacromet layer is applied by zinc flakes in a cold dip and spin process, dried and heated into the product at about 300 degrees Celsius. 

Zinc-flake coatings are used to protect parts - like disc rotors, leaf springs, drums, calipers, u-bolts and fasteners. It has high corrosion protection and it is suited for thin layer thicknesses or detailed surfaces for a high quality finish. Zinc-flake coatings are resistant to both acidic and basic chemicals. 

Hot dipped Galvanising

Hot dipped galvanising has been around for a long time and is best known. The part is dipped into a molten zinc mixture at a temperature of about 460 degrees Celsius which reacts with carbon dioxide to form zinc carbonate. It can usually be identified by the crystallisation pattern on the surface, called a spangle. 

Hot dip galvanising covers the steel and seals it forming a strong material that stops corrosion and protects steel from the elements. The finish is not as attractive and thicker than zinc-flake. It is not suitable for parts with threads or fine detail due to its thickness.