An ultra-high solids content primer coating composition comprising: (i) 5.0 to 50 wt % of at least one bisphenol F epoxy resin; (ii) 1.5 to 12 wt % of at least one silane; (iii) 0 to 20 wt % of at least one hydrocarbon resin; (iv) 0 to 15 wt % of at least one reactive diluent; (v) at least one curing agent; wherein said composition has a solids content of at least 90 wt % according to ASTM D5201-05; wherein said composition has a viscosity of 200 to 800 cps at 23° C. and 50% RH (ASTM D4287); and wherein the ratio between hydrogen equivalents in the curing agent and epoxy equivalents of the coating composition is in the range 50:100 to 120:100.