A process for the preparation of an outdoor article, wherein the outdoor article is an insulation system for electrical engineering prepared by casting, potting, encapsulation, or an impregnation process. wherein a thermosetting resin composition is used, said resin composition comprising a glycidyl-type epoxy resin comprising a mixture of from 10 wt% to 90 wt% of at least one cycloaliphatic glycidyl-type epoxy resin without an ester group selected from a polyglycidylether of 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol (quinitol), 1,4-bis(hydroxymethyl)cyclohexane, 1,1-bis(hydroxymethyl)cyclohex-3-ene, bis(4-hydroxycyclohexyl)methane (hydrogenated bisphenol F), 2,2-bis(4-hydroxycyclohexyl)propane (hydrogenated bisphenol A), 2,2-bis(3-methyl-4-hydroxycyclohexyl)propane (hydrogenated bisphenol C), 1,1-bis(4-hydroxycyclohexyl)ethane (hydrogenated bisphenol E), 1,3-cyclopentanediol, 4,4'-dihydroxydicyclohexane, 2,6-bis(4'-hydroxycyclohexylmethyl)-1-hydroxycyclohexane, 1,3,5-trihydroxycyclohexane, 1,2,2-tris(4-hydroxycyclohexyl)ethane, or hydrogenated phenolformaldehyde condensation products having 3 to 10 cyclohexane rings, and from 90 wt% to 10 wt% of at least one cycloaliphatic glycidyl-type epoxy resin containing an ester group selected from diglycidyl-4,5-epoxycyclohexane-3-methyl-1,2-dicarboxylate, diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate, hexahydrophthalic acid-bis-glycidyl-ester, diglycidyl-3,4-epoxycyclohexane-1,1-dicarboxylate, glycidyl-3,4-epoxycyclohexane carboxylate, or 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, each based on the total weight of and, at least one cationic curing agent selected from dibenzylphenylsulfonium hexafluoroantimonate, or N-benzylquinolinium hexafluoroantimonate together with 1,1,2,2-tetraphenyl-1,2-ethanediol (benzopinacol), and optionally at least one silanized filler. a glycidyl-type epoxy resin comprising a mixture of from 10 wt% to 90 wt% of at least one cycloaliphatic glycidyl-type epoxy resin without an ester group selected from a polyglycidylether of 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol (quinitol), 1,4-bis(hydroxymethyl)cyclohexane, 1,1-bis(hydroxymethyl)cyclohex-3-ene, bis(4-hydroxycyclohexyl)methane (hydrogenated bisphenol F), 2,2-bis(4-hydroxycyclohexyl)propane (hydrogenated bisphenol A), 2,2-bis(3-methyl-4-hydroxycyclohexyl)propane (hydrogenated bisphenol C), 1,1-bis(4-hydroxycyclohexyl)ethane (hydrogenated bisphenol E), 1,3-cyclopentanediol, 4,4'-dihydroxydicyclohexane, 2,6-bis(4'-hydroxycyclohexylmethyl)-1-hydroxycyclohexane, 1,3,5-trihydroxycyclohexane, 1,2,2-tris(4-hydroxycyclohexyl)ethane, or hydrogenated phenolformaldehyde condensation products having 3 to 10 cyclohexane rings, and from 90 wt% to 10 wt% of at least one cycloaliphatic glycidyl-type epoxy resin containing an ester group selected from diglycidyl-4,5-epoxycyclohexane-3-methyl-1,2-dicarboxylate, diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate, hexahydrophthalic acid-bis-glycidyl-ester, diglycidyl-3,4-epoxycyclohexane-1,1-dicarboxylate, glycidyl-3,4-epoxycyclohexane carboxylate, or 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, each based on the total weight of and, from 10 wt% to 90 wt% of at least one cycloaliphatic glycidyl-type epoxy resin without an ester group selected from a polyglycidylether of 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol (quinitol), 1,4-bis(hydroxymethyl)cyclohexane, 1,1-bis(hydroxymethyl)cyclohex-3-ene, bis(4-hydroxycyclohexyl)methane (hydrogenated bisphenol F), 2,2-bis(4-hydroxycyclohexyl)propane (hydrogenated bisphenol A), 2,2-bis(3-methyl-4-hydroxycyclohexyl)propane (hydrogenated bisphenol C), 1,1-bis(4-hydroxycyclohexyl)ethane (hydrogenated bisphenol E), 1,3-cyclopentanediol, 4,4'-dihydroxydicyclohexane, 2,6-bis(4'-hydroxycyclohexylmethyl)-1-hydroxycyclohexane, 1,3,5-trihydroxycyclohexane, 1,2,2-tris(4-hydroxycyclohexyl)ethane, or hydrogenated phenolformaldehyde condensation products having 3 to 10 cyclohexane rings, and from 90 wt% to 10 wt% of at least one cycloaliphatic glycidyl-type epoxy resin containing an ester group selected from diglycidyl-4,5-epoxycyclohexane-3-methyl-1,2-dicarboxylate, diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate, hexahydrophthalic acid-bis-glycidyl-ester, diglycidyl-3,4-epoxycyclohexane-1,1-dicarboxylate, glycidyl-3,4-epoxycyclohexane carboxylate, or 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, at least one cationic curing agent selected from dibenzylphenylsulfonium hexafluoroantimonate, or N-benzylquinolinium hexafluoroantimonate together with 1,1,2,2-tetraphenyl-1,2-ethanediol (benzopinacol), and optionally at least one silanized filler.