The invention relates to an application device with a handle part and an application part, the application part having a surface onto which a redox initiator system is located, the redox initiator system comprising either hydrophilic oxidizing agent(s) and hydrophobic reducing agent (s), or hydrophobic oxidizing agent(s) and hydrophilic reducing agent(s). The invention also relates to a kit comprising the application device, a method of producing the application device and a method or curing a curable composition using the application device.