Originally Posted by mturnerb
Another question - what did you use to adhere backing plates to lens? I initially tried double-sided tape but it has some thickness that allows the nutplates to "sag" against lens when screws are snugged up. What's safe to use on lexi?
I used proseal. Not sure I would do it again though. I did a little research and couldn't find much on the subject of compatibility with the plexiglass long term.
To check adhesion, I did a test using some of the scrap plexi trimmed from the lens and a piece of aluminum. I scuffed the plexi pretty good and cleaned with naphtha. After the test piece cured, I pulled the pieces apart. Definitely enough adhesion to hold the pieces together, but not like when bonding aluminum together..as expected.
For final assembly of the lens, I applied the proseal to the brackets using an acid brush with trimmed bristles and then clecoed in place with silver clecos through the nutplates. After the proseal set up slightly, I removed clecos and screwed lens in place in the leading edge.
Like I said probably wouldn't do it that way again. Even though I had the lens taped up to prevent proseal where I did't want it , I still had a bit of a mess when the proseal squeezed out from the clecos and screws. I still have a bit of cleanup to figure out there.
Looking back, I think this is a good case for the "kiss" principle. I like John-G's string idea,...especially if you're able to get your fingers on the backing plate to hold some light pressure when tightening the screws.