Hi!
What you have done in the picture is fine but not the best way of doing it!
A much better way is to use thinner glass cloth (25g) and put on several layers (3-4) in different widths. That way you don't get a sharp ridge where the glass ends. What happens when you put load on the wing is that it might (will) break where the glass fiber ends , like tearing toilet papper.

And do not use the glue variety of epoxy!
Use laminating (24 hour ) epoxy! It's much thinner and easier to sand and most important ...Oracover (which is the best plastic covering) stick to it better than epoxy glue.