Yesterday I marked up the window where I needed to tape it off for the Sikaflex. I also sorted out what spacers I needed under it in order to have it match up relatively evenly with the main canopy. Since I'm going to put a fiberglass targa strip over the whole thing, it doesn't have to be perfect, but the closer it is the easier it'll be to fiberglass. I just used various pieces of wire - I think that'll be easy to pull out once the Sika is cured (then I'll just fill the holes in).
I pulled the window back off and scuffed up the plexi plus the rollbar and inside of the fuselage skin.
I cleaned the plexi with the Sika activator, then put the primer on and let it flash for 30 minutes.
The rollbar and skin got the same treatment.
Now for the messy part. The window has to be slid underneath the skin and set on top of the rollbar. The center of the aft part fits in a very tight space between the skin and the center brace that goes to the rollbar. I think I sat and stared at it for 10 minutes before I got up the nerve to go for it. In the end I got it slid around and in the right spot with all of the spaces correct, but in doing so I made a total mess! Even though I had most everything taped off, I still managed to get Sika all over things that shouldn't have Sika on them. Luckily, the adhesive doesn't stick very well to anything that isn't primed, so once it cures I will be able to clean it off. I pull a strap over the top to pull the window down onto the spacers, and I used some blocks cut to the shape of the fuselage to pull in the skins at the side.
The window naturally springs out against the skin, but the 10 and 2 locations still sag a little. I used some old scrap flooring (a little flexible) and some foam to push the window out. Now I just have to wait for a day and cross my fingers. I pulled most of the electrical tape off while everything was still wet, but I didn't crawl around too much to see how things look. At this stage it's too late already anyway, so I might as well let it dry before I poke around and just make it messier. I'm sure there's going to be a decent amount of clean up to do, as well as another layer of Sika in places. I don't think I actually put as much adhesive on as I could have (I didn't see it squeeze out in most places), but in terms of strength, a little Sika goes a long ways, so it'll be fine.
