I had a lot of angst about doing the trailing edge. I over-analyzed it for a couple weeks, and read too many posts online about how to do it. When it came down to it, it was a simple process.
I waited until the entire rudder was fully sealed up – skin and all – except for the top. I got some tongue depressors (Dad is a retired doctor), and carefully wedged pairs of them between the skins along the trailing edge, to act as a “guide” to getting the wedge between the skins at the trailing edge. I dabbed ProSeal on both sides of the wedge, then slipped it up between the tongue depressors and into position. Popsicle sticks would do just as well, I imagine. Once the wedge was in place, I cleco’d the TE to the match-drilled angle aluminum so that the trailing edge would stay straight while the ProSeal cured. I didn’t touch the rudder for a couple days – the sealant stayed tacky longer than I figured it would.
I thought the directions that came with the ProSeal were not very good. I ended up setting the directions aside and just looking at it, figuring it out. The black rod ends up pushing the sealant from the bottom, to force the sealant out the top (where you’ve screwed on the tip). The initial mixing of the two substances together was easy, as long as you do your best to evenly distribute the activating substance.