Hi...

I am building a 'D' tube type wing using 1 mm sheeting. I am happy with the stiffness this has created across the whole wing, however with little pressure the sheeting is soft and sags a little between ribs. Is there any benefit from applying dope or anything else not too heavy to stiffen/strengthen the sheeting in between ribs?

Could appying dope end up actually warping the wing if applied to the sheeting? I would greatly appreciate words of wisdom and experience