Ok, so here's the update.
Bodyshop jacked it up. They went to sand it and it cracked. This is hard to beleive because I've been flexing it, mounting it, unmounting it, sanding it, etc, and it never cracked. Whatever, whats done is done. What really pissed me off though, is they ground down the side that cracked and started experimenting with the hotmelt stuff and trying to peel off the two-part on the back. Basicly, I have to completely redo the left side of the bumper from scratch.
So. I gave it some more thought, and tried something a little different to make sure it is as durable as its ever going to get. I started by drilling a series of 1/16" holes, about 1/8" back from the edge on both sides of the seem. Then I used the Flexible Ure-Weld that I was using to reinforce the back of the seem on the seem itself, skipping the hotmelt process (which had I had more welding rod I would have still used the hotmelt too), and applied it to both sides of the seem. Thin coat on top, but pushed it through all the little holes I drilled so it basicly will "lock" around the substrate. The result, before topping it off with filler, looks like this:
It definately feels much stronger than it was before. It really feels like one peice. It did flex a little before, but its not a real stress point on the bumper so I dont think it would've been a problem, but at least now I know it wont ever be a problem anymore. Its not going anywhere.
Having done this once before makes it easier. I just did this repair in about an hour, which is far less than it would've taken me before.
So tentatively, I'll have the filler done tonight or tomorrow, and I already confirmed with the body shop that when I bring it back on Monday morning they'll prime it that day, and paint on Tuesday.
