RE: Hate it when the expiration date matches the maiden..
Let us know what H9 does for you. It will be interesting to see if they will replace it.
Whether the tape is strong or not, that is not the proper way to join wing halves. Since I am experienced I would know to epoxy the halves together and glass it.
Your friend had no idea, but that is not the point. The manual should, or actually the MFG should have had a better assembly plan.
Good luck.