RE: flying unpainted DF ?
Not a problem. I always put 20 flights on my new planes before painting them.
Here is what I do...
I spray a light coat of K36(outdated)/K38 primer(replacement) over the plane. After 20 flights, I fill the nicks, clean the primer with the standard degreaser and give it a light sanding-taking most of the primer down but not to the glass. I then spray another light coat and sand to prep for the final coat. The second coat ensure the finish is flawless after flying and ensures the paint sees no impurities.
That should do it.
Dave
(A fellow Canadian from Montreal~!)