RE: Sheeting Foam Wings question
I have used PU but because of the large weights and long wait have returned to Sorghum.
I first edge glue, with thin CA, the balsa sheet to give the necesary width. Then spread the Sorghum thinly on foam and sheet (useing a 'pretend' credit card) and leave to dry. When both are dry to the touch roll the sheet on while pressing down. Make sure it lines up, because once contact is made - it's stuck. It then ready to be trimmed for LE and TE.