Hi, Tim.
The whole process took me about an hour this morning..used the scotchbrite (red pad) and straight Simple Green out of the spray bottle, but mine had 13K mi of road grime on it. I just sprayed the tray, dipped the scotchbrite in some water and scrubbed the surface of the tray all over like I was giving it a good clean. I then wiped the surface down with a towel and let it air dry. After that, I used some 2" wide masking tape and taped up around the aluminum boardering the tray along with the underside of the body and frame members at the rear of the tray. I then got the satin Krylon out and put three coats on. This was the result:
I don't really expect that there will be an adhesion issue as the tray surface is quite "keyed" just with the texture of the un-gel coated fiberglass. And I've not noticed any "residue" left behind after using the Simple Green. It's good stuff and reasonably inexpensive. Lowes sells gallon jugs of it for under $10. Once you start using it, you'll find all kinds of ways to get through that gallon jug.
On second thought, it might take you a bit longer than an hour to do it....I had this guy helping me:
- Allen.