A two-part curable coating composition comprising: a composition comprising an alkoxysilane terminated polyester urethane prepolymer, comprising a prepolymer chain having a terminal group of general formula: wherein: Y represents: H; R 1 wherein R 1 represents hydrocarbyl, preferably alkyl or aryl, optionally wherein R 1 at each occurrence is the same or different, preferably the same, and each is independently selected from: a C 1 to C 6 alkyl, or a C 1 to C 4 alkyl group, more preferably each is a methyl or ethyl group; or wherein Y represents the group: and preferably wherein Y is H; L represents a hydrocarbylene group, preferably an alkylene or an arylene group, preferably a C 1 to C 10 hydrocarbylene group, and preferably methylene, ethylene, or propylene and most preferably propylene; W 1, W 2, W 3, W 4, W 5 and W 6 may be the same or different and each independently represents -OR 2, wherein R 2 at each occurrence may be the same or different, and each R 2 is independently selected from an alkyl group, preferably wherein the alkyl group has 1 to 10 carbon atoms, and preferably wherein the alkyl group has 1 to 8 atoms, preferably methyl or ethyl, and most preferably methyl; and a composition comprising a silanol terminated polysiloxane prepolymer obtainable by sol-gel process of an alkoxysilane selected from a compound of general formula, or: wherein: X 1, X 2, X 3, X 4, X 5, and X 6 each represents -OR 3; R 3 at each occurrence is the same or different, and each is independently selected from an alkyl group, wherein the alkyl group has 1 to 10 carbon atoms, preferably 1 to 8 atoms, more preferably 1 to 6 carbon atoms, and most preferably 1 to 4 carbon atoms; and m represents an integer from 1 to 6, preferably 1 to 3. a composition comprising an alkoxysilane terminated polyester urethane prepolymer, comprising a prepolymer chain having a terminal group of general formula: wherein: Y represents: H; R 1 wherein R 1 represents hydrocarbyl, preferably alkyl or aryl, optionally wherein R 1 at each occurrence is the same or different, preferably the same, and each is independently selected from: a C 1 to C 6 alkyl, or a C 1 to C 4 alkyl group, more preferably each is a methyl or ethyl group; or wherein Y represents the group: and preferably wherein Y is H; L represents a hydrocarbylene group, preferably an alkylene or an arylene group, preferably a C 1 to C 10 hydrocarbylene group, and preferably methylene, ethylene, or propylene and most preferably propylene; W 1, W 2, W 3, W 4, W 5 and W 6 may be the same or different and each independently represents -OR 2, wherein R 2 at each occurrence may be the same or different, and each R 2 is independently selected from an alkyl group, preferably wherein the alkyl group has 1 to 10 carbon atoms, and preferably wherein the alkyl group has 1 to 8 atoms, preferably methyl or ethyl, and most preferably methyl; and Y represents: H; R 1 wherein R 1 represents hydrocarbyl, preferably alkyl or aryl, optionally wherein R 1 at each occurrence is the same or different, preferably the same, and each is independently selected from: a C 1 to C 6 alkyl, or a C 1 to C 4 alkyl group, more preferably each is a methyl or ethyl group; or wherein Y represents the group: and preferably wherein Y is H; L represents a hydrocarbylene group, preferably an alkylene or an arylene group, preferably a C 1 to C 10 hydrocarbylene group, and preferably methylene, ethylene, or propylene and most preferably propylene; W 1, W 2, W 3, W 4, W 5 and W 6 may be the same or different and each independently represents -OR 2, wherein R 2 at each occurrence may be the same or different, and each R 2 is independently selected from an alkyl group, preferably wherein the alkyl group has 1 to 10 carbon atoms, and preferably wherein the alkyl group has 1 to 8 atoms, preferably methyl or ethyl, and most preferably methyl; a composition comprising a silanol terminated polysiloxane prepolymer obtainable by sol-gel process of an alkoxysilane selected from a compound of general formula, or: wherein: X 1, X 2, X 3, X 4, X 5, and X 6 each represents -OR 3; R 3 at each occurrence is the same or different, and each is independently selected from an alkyl group, wherein the alkyl group has 1 to 10 carbon atoms, preferably 1 to 8 atoms, more preferably 1 to 6 carbon atoms, and most preferably 1 to 4 carbon atoms; and m represents an integer from 1 to 6, preferably 1 to 3. X 1, X 2, X 3, X 4, X 5, and X 6 each represents -OR 3; R 3 at each occurrence is the same or different, and each is independently selected from an alkyl group, wherein the alkyl group has 1 to 10 carbon atoms, preferably 1 to 8 atoms, more preferably 1 to 6 carbon atoms, and most preferably 1 to 4 carbon atoms; and m represents an integer from 1 to 6, preferably 1 to 3.