Thanks guys...I have been fabbing up some removeable mud flaps for my Jeep. Thought I would start there.
Per your comment Louisd75...I too was concerned about rock guard adhering to the aluminum as you noted.
When I redid it I sanded with 60 grit, thoroughly cleaned and degreased, then used the Raptor acid etching primer before doing the Raptor. Raptor is set up so that you pour bottle A into bottle B, then shake it up and spray. There is an additional bottle if you're not going with a pre-made color. I went with Dove Gray from U-Pol (pretty sure U-Pol owns Raptor). I found that this makes it too easy to put the coating on too thick. If you do it too thick then it will shrink slightly as it cures. Not a big deal on a flat surface, but if you have an inside corner or concave surface it can lift off. I wound up having much better luck mixing small batches by weight and spraying a light coat til I ran out, then mixing another small batch. I went by weigh vs volume since volume can change with temperature. It probably wouldn't change enough to matter really, but after having the experience of removing the bed liner, I didn't want to take any chances my second time around. If you do have to remove it after curing, I recommend one of the multi-purpose stainless steel paint scrapers and a side to side wiggling motion. The motion is like trying to get a flipper under an egg without breaking the yolk. If you have the kind of edge trim that takes a vinyl insert, you can remove the vinyl insert and cover it with masking tape, then reinstall. Waaay easier than trying to mask the channel. Pull the trim out once the coat starts to get tacky and do new tape before you do the next coat.
I've had no issues since re-coating and the trailer has been in 90* temps with direct sunlight as well as below freezing. I do typically garage the trailer, so I can't speak for long term UV resistance but so far I've been happy. The fenders were lined over Rustoleum enamel paint & primer on top of steel and have had no issues.
The vast majority of the gravel pitting happened on the front of the fenders and on the lower half of the front curve. There wasn't much on the tongue box or under the front window. There was also very little gravel pitting once you got about a 18" or so above the bottom edge of the trailer. The windows are 1/4" Polycarbonate and have no impact marks. I don't know if this is luck or if the vast majority of gravel just isn't making it that high.
![Bedliner Redo.jpg Bedliner Redo.jpg](https://expeditionportal.com/forum/data/attachments/613/613025-42315094428c24b952fbcc0589a5b645.jpg)