Steel is an alloy which mainly contains iron. Carbon is the most common and important additive. Alloys with high content of carbon is called cast iron.

Cast iron contains 2-4% carbon and can be very brittle. In the yacht industry you can find keels and engines made in cast iron.

Cast iron should be treated as “normal” steel and need a good preparation and a rust barrier in the form of a 2-pack or 1 –pack primer.