I repaired a mount point on the rear panel of my F3 using a thing called tigers hair. It is bondo with fiberglass in it. Mix it with the hardner and apply it to a clean sanded surface. If you build it up from the inside over a wide area and sand it down to a uniform level I bet it would hold. My repair has held for over a year so far.
I got the "Tigers Hair" from a paint and body supply shop.
Good Luck!
Mikey

 

I was told differently, how do you know its better? I have used similar stuff that you did on more flexible pieces and it didn't hold up. Uppers are easy to fix with just about anything, they are very rigid to begin with. Pieces that flex like rear an lower fairings always ended up breaking again until I got them plastic welded.

EIther way, plastic welding is still cheaper than the 120 you spend and still strong.

 

Well i just sold my car so i know have the cash to buy me some pretty fairings. Haha im keeping the old ones so i can build my skill at fairing repair. Thanks for the replys though.