still i ask why you dont want to sheet the LE and TE... also sheetign the middle kinda involves sheeting which is exactly what he/she doesnet want to do if i understand original post correctly, just read up on sheeting or pm me and sheet LE and TE youl be much happier when you have a hard landing and the wing is stiff enough not to snap if it nicks the runway.

-edit-

i personaly sheet the whole wing and fuse, makes for better airflow ill post pic of uncovered Kadet Mark II after i take some pics :-)