what to do with a idiot

i have a friend that is build a full size chevy. he has no experiance as a fab. guy and he decided to sfbd his truck. i told him that i would help him after he started and he is doing it buy him self. i stopped bye yesterday and check out how it was goin and it is totally unsafe. he has gusseted his frame with freakin sheet metal like 18 guage. i have told him several times that he has to make things strong but he doesnt seem to understand. what should i do what are my options. suggestions would be appreciated.