Huh... I could have SWORN I had already replied to this... Strange!
+1 for truck box spray liner.
That good stuff is TOUGH!!
The professional shop stuff is much better than what you get in a can at the parts store and the coating shops will happily coat other items than truck boxes for you. People do it all the time with road cases, P.A. speaker enclosures, etc.
Aye, I think that will be the way to go!
How flexible is it? For instance, if the underlying aluminium is bent or flexed, will it crack and flake off?
If you want it to stand up to abuse, you'll need to prime the aluminium with an etch wash primer, and may still need a tie coat of something like a hard polyurethane before applying the bedliner.
I'll speak to the local car shops later today and see if they'll do proper priming/tie coat as part of their application process and see what they say - worst case scenario I'll shot-blast the aluminium and get it primed.
Yeah, underbody sealant is not suited. It can stay tacky and makes your hands grubby.
You bet me to it! I actually figured that one out myself: I got the magical idea of visiting a local autorepair shop and explained that I was considering coating something in the sealant and wanted to get a quick look at what it was like when freshly applied/dried.
Apparently there are two variants of it - air-dry kind and uv-cured: air-dried tends to have a tacky feel to it and the uv-cured stuff (which they didn't have in the shop, they only buy it in when they need it) has an oilier feel to it - but both will pick up crap and wouldn't be good for coating a frame
I wish I had mentioned what I planned on coating to them - they might actually have suggested the truck-box spray-liner themselves!
Oh well - will let you know how it turns out.