Maybe this is a special situation, but not too many people can appreciate the level of work that goes into something like that repair..In my book,with your level of competence and ability you should be charging them 5hrs of labor when you include expendables like shield gas, the electric to run everything, filler wire, shop towels and degreaser, etc, etc I look people straight in the face and tell them $102 an hour..some people grumble,turn and walk away, some say no problem..the latter are the people I want to work for. That way I feel better about putting MY projects on the back burner when repairing someone else's stuff. Maybe that sounds selfish,I don't think so..
