I've used a Pop Riveter over the past 75 years but only to join metal maybe two to three millimetres thick when patching a car up and to hold the metal while I welded it. Today I attempted to join a thin two/three mm metal skin of a shed to a 5mm mm thick Strengthening strip and it wouldn’t work. The thought crossed m y mind that my Pop Riveter gun was a one purpose tool or am I wrong? Anyway, would someone by kind enough to tell me what sort of a Pop Riveter gun I need for my task? Many thanks.