Skinny guys dont forget that your body recovers and becomes stronger in rest not in the gym.  I have been doing a study where I have been taking off 1/2 of a week in between full body workouts and have found that I am making good strength gains.   It really did suprise me.  Your body only recognizes the amount of stress and fatigue you put it through.  Not the amount of reps and sets you do.  So dont fool yourself.  Work on insti nct. A lean guy will build more muscle  following the right weight training program, and nutrition program.