Discoloration on top of camper/bottom of bunks?

[woody]

Doing more tweaking to my new-to-me XLP.  I noticed when I bought it that under the tarp is a lot of discoloration and it's fairly rough.  I figured it would scrub off or possibly wax off.  Tried several things today to get it off and really nothing changed it much.  Anyone else have this?  Not sure if it's from storage or the tarp rubbing on it going down the road.  I'm considering masking it off and painting it with some Rustoleum or something at some point.  I know under the tarp nobody sees it, but it still bothers me.  

[admin]

I have not noticed any discoloration on my 10.0 nor any wear to the bunks. Could you describe the discoloration more? I'm having a hard time picturing what this could look like.

[woody]

Below are links to a couple of pictures I took.  It looks as though it was where the tarp has been sitting on it or perhaps where it rubbed on it going down the road.  The bottom of the tarp (which needs replaced) is stained also.  Are the undersides of the bunk raw aluminum or painted?  It is hard for me to tell.  I have tried dish soap, bar keepers friend, totally awesome, rubbing compound, and meguiars cleaner/wax.  None of them really affect it at all.  I'm now considering either "Brite Kleen":  http://britekleensolutions.com/about-britekleen-solutions or just painting it.  Just wondered if anyone else had this happened or would know what caused it so if I get it taken care of it doesn't happen again.

[subaruwx]

My thought is that perhaps the vinyl cover is breaking down? Do you know if something was pressed on top of the cover when it was out in the hot sun?  Try some acetone or nail polish remover on a small section and see if that helps.

[admin]

The bottoms of the bunks should be the same material as the rest of the skin on the trailer. My first reaction when I looked at the pictures was that it just looked like dirt. On second look it clearly looks like its a reaction to the cover in some way. Some of it might be from rubbing in the wind, but other parts look like it was from the top sitting in one place. The question about it sitting in the hot sun with something on top of it is a good question. I would also ask about weather...did it sit in prolonged periods of wet weather where water had built up?

-Sean

[funpilot]

One more approach to consider.  It could be black fungus that grew on it while being covered.  Easy to test as I would use diluted bleach on it.  You need to keep it wet with the bleach solution for a while to kill it, if it is fungus.  Then scrub hard to remove it.  I see something like this on my sunshades that I have over my koi pond that I have to clean every year with bleach. I dilute it by 50%.  It is a pain, but it does come off if that is what it is.

[woody]

Thanks for all the ideas.  Sounds like I'm the only lucky one that this has happened with.  I tried some xylene on a little spot to see what that would do.  That took it right off - left a bright shiny spot.  Which brings me back to - are the bunk bottoms/top of camper painted or raw aluminum?  My sides are painted silver so it's kind of hard to tell.  The yellow QS10 in the demo on the website they are silver - which makes me think raw aluminum.  Anyway - just wondering if I go the Xylene route over the whole thing, if I'll need to replace it with some sort of protective coating (paint or otherwise).