Well got things sorted the heat gun did the trick. like u said buildflycrash pull it tight tack and seal with iron then hit with heat gun and presto done. the under side of the wing does not look to great but better than it was. so now the wing and fuse are covered. Also must say the monokote seems to be on the heavy side so hope it has not added to much extra weight.
I will be installing a small light ply plate on the surfaces to go under the control horns as the balsa seems to be a soft, i just want to give something to bit into.
then finish covering and onto final assembly YAY getting there