ORIGINAL: HighPlains
Balsa fuselages:
I put the wing on the fuselage with a strip of sandpaper and pull out the sandpaper until the fuselage fits the wing perfectly.
Glass fuselage:
Pot it with epoxy and cabosil/micro ballon mix over plastic release film.
Lite ply fuselage:
Who cares, not a quality airplane.
So a balsa fuselage is more quality than a lite ply?
Edit:
Sorry, that is not the argument, I will try to add to the post.
I try to sand the joint until it fits snug. Putting sheet sandpaper between the fuse and wing works well. However, if you have large areas that need filling, then the epoxy/baloon with wax paper is the way to go, then sand that down to match the fuse sides and you'll be set.
Also, there is nothing wrong with wing seat foam tape. I've used it quite a bit. One thingit is often better to go ahead and CA the foam tape to the saddle, as that adhesive it comes with is usually poor quality.
BTW, this same foam tape can be had at Lowes or similar home improvement place for pennies on the dollar compared to the LHS.
As always, be careful when you are sanding the wing saddle as you can run into incidence troubles.