In reconstructing these, I first made a wooden template suitable for a router. I used MDF (medium density fibreboard).
Next I procured some PVC board, which when doubling the thickness of the PVC board, was just a few millimeters thicker than my old bug screen.
I used PVC, but could just as easily have worked with Polyethylene plastic board.
Next I cut out of the PVC board, four rough finished frames which were about 5-10mm wider than my template.
You might notice that my template has a wider surface than the original bug screen. This was to give it some added sthrengh and make it easier to place the bug mesh between the two PVC cutouts.
Then because my template wasn't exactly symmetrical I matched two pairs so that all corners lined up perfectly.
|Mesh glued and trimmed|
|4000 applied before 2nd side attached|
|Glass over top for glue to set|
Finally the other side was applied, being careful that both PVC cutouts lined up perfectly. The PVC was pressed down from the inside edge to the outside, squeezing out any excess 4000. A plate of glass was applied over the two pieces and allowed to set up.
After it has set up, a sharp craft knife was used to trim the excess off, on the outside edge.
What am I going to secure it with in the port hole? Probably "blue tack"; but one could use a double sided foam tape, like they use to secure mirrors on walls.
Don't try to do the glueing in one step with the mesh. I tried and it was very difficult to have both PVC pieces line up perfectly. Also when trimming the mesh off, you could still see the mesh on the outer edge and it looked "ugly". A much better finish, if you glue the mesh to one piece first; have it set up, and trim the mesh back from the out edge. Then, when trimming the final outer edge of 4000 is done, a nice white finish is all you see. So, in essence, what you see here is a bug screen that has had the mesh replaced once because I didn't do it right first time. Cost $30 for the PVC 1 square meter sheet; and $7 for the mesh.