Coating system

A curable composition comprising:

• a) an epoxy resin containing on average more than one epoxy group per molecule;
• and
• b) as curing agent, a hybrid hardener;
• wherein said hybrid hardener is a blend of b1) and b2):
• b1) an aminic compound selected from the group consisting of aliphatic amines, cycloaliphatic amines, araliphatic amines, imidazoline group-containing amidoamines based on mono- or polybasic acids, adducts of said amines or amidoamines and glycidyl compounds, and adducts of said amines or amidoamines and cyclic carbonates, wherein said aminic compound contains, on average per molecule, at least two reactive hydrogen atoms bound to nitrogen atoms;
• and
• b2) a polyphenol novolac, wherein the polyphenol novolac is present in an amount of from 30% to 45% by weight, based on the total weight of the blend of b1) and b2);
• wherein the hybrid hardener is a liquid having a viscosity lower than 20,000 mPa·s at a temperature of 20±5° C.;
• and
• wherein the curable composition is a protective coating curable at a temperature of from about −5° C. to about 50° C.