Abstract: The present invention provides curable moldable compositions comprising from 10 to 80 volume % of heat resistant fiber compositions, a two component resin mixture of (i) one or more epoxy resins, and (ii) a hardener comprising a combination of triethylenetetraamine (TETA) and from 3 to 15 wt. %, based on the weight of the TETA, of 2-phenylimidazole (2-PI). The compositions cure to provide composite articles having a short demold time of 90 s or less at 130° C. and 101 kPa and a high DSC glass transition temperature (Tg) of from 130 to 180° C. when cured at 130° C. for 90 seconds at a pressure of 101 kPa. The invention enables lightweight, heat resistant composite articles, such as for use in automotive applications.