Hi!
Sorry! I don't won't to be rude in any way ... But that looks terrible!

It's not a good thing using so thick and so straight edged glass fiber. The reason for this is the edge is working like a cutting edge where the wing is likely to split. And second, using glue epoxy glue is not recommended,it's too thick and rubbery! Ca should also be avoided as there are much better alternatives.

What you should do if you want to have a strong wing center section with no visible edges is to use several layers of 25g glass weave that you cut in a diamond pattern so the largest is above all the rest. 4 layers is enough for a .40size plane. And you use either polyester resin or better yet; 24 hour professional epoxy . This epoxy is thin and cures after aprx 24 hours. You lay the glassfiber on the wing , pour out the epoxy and either brush it out or use a plastic spreader from SIG or Flash. Do not use a credit card as these are to thick and small.
No hair spray or any other such thing is needed!!!

When you are finished you roll a paper towel over the surface to suck up unwanted epoxy, if the surface is hard to reach, you use a small peace paper that you dab onto the surface.

When it comes to laminating epoxies West systems make a rather good one, but there are better ones available if you seek the web.