Losing the vertical line on my table when using multicolumn

Question

I tried to use this for the last part of my table, but I can't get a vertical line at the end. Does anyone know?

 \begin{tabular}{|CC|C|C|C|C|C|C|C|C|C|C|}\hline
\Tab{Method Based on \\\hline 
     Radiography\\Magnetic Particle (A.C.)\\ \\Eddy Current\\Dye Penetrants\\ Ultrasonics}
&
\Tab{ \\\hline \\ Wet \\ Dry \\ \\ \\ \\}
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Minute Surface Cracks
}~}  \\\hline 
     N\\ G\\F\\F\\F\\P}
 &
\Tab{\rotatebox{90}{~\parbox{5cm}{Deeper Surface Cracks
     }~}  \\\hline 
          F\\G\\G\\G\\G\\G}
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Internal Cracks
     }~}  \\\hline 
          F\\N\\N\\N\\N\\G}
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Fatigue Cracks
     }~}  \\\hline 
          P\\G\\G\\N\\G\\G}
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Internal Voids
     }~}  \\\hline 
          G\\N\\N\\N\\N\\G}          
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Porosity and Slag in Welds
     }~}  \\\hline 
          G\\N\\N\\P\\N\\F}          
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Thickness
     }~}  \\\hline 
          F\\N\\N\\P\\N\\G}
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Stress Corrosion
     }~}  \\\hline 
          F\\G\\F\\N\\G\\F}
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Blistering
     }~}  \\\hline 
          P\\N\\N\\N\\N\\F}
&
\Tab{\rotatebox{90}{~\parbox{5cm}{Corrosion Pits
     }~}  \\\hline 
          G\\N\\P\\N\\F\\P}
\\\hline
&
\multicolumn{11}{l}{G=Good;F=Fair;P=Poor;N=Not suitable.} \\
\hline
\end{tabular}
\label{tab:NDETechniques}
\end{table}

It comes out like this:

Answer 1

You have to repeat the vertical specifier in the column specification of \multicolumn:

\multicolumn{11}{l|}{...}