Siding discoloration

[gatorguy]

First time posting here but I have read on the forum a lot as a guest.

My in-laws have a 2007 Fleetwood 365FLTS AX6 which stands for 6 sided aluminum I believe.

There are several spots on the siding that is turning a brown color and we can't figure out what's causing it. I took a couple pictures to better illustrate what I'm talking about. It seems to be seeping to the outside of the skin from within as it doesn't wipe off.

It seems that most of the discoloration is occurring near some opening in the siding whether it be an electrical socket, storage door etc.

[dockmasterdave]

You could also try a small bottle of polishing compound, or rubbing compound. Auto parts store or wallyworld. Should be under $10.

[gatorguy]

Thanks for the advice. I'll tell them to try some polish and report back. Has anyone ever used Streak-X? Supposedly it does a real good job removing the black mildew streaks. I might try a sample size of that next if the polish doesn't do anything.

[ScottG]

Give the polish a try.
One spring after storing my TT covered over the winter, I had some very similar splotches on the back of my RV. I never could figure out where they came from and it hasn't happened since. It took a lot of effort but I was finally able to polish them away.

[dockmasterdave]

I would have to guess some sort of contamination got on it during the building process before paint.
I don't think there will be a rub on/ rub off fix. Most likely some painting in the future.
Hopefully I'm wrong, and some one who has been through the exact same thing, will have some good advice.

[gatorguy]

dockmasterdave wrote:
Are you sure that is aluminum? Looks like a fiberglass sided unit.

I'm not sure, I'll try to find out next time I see it (it will be a few weeks). If it is fiberglass, what do you think it could be?

ScottG wrote:
Have they tried taking some car polish (like Turtle wax) to it and really rub it in?

Haven't tried car polish but will give that a shot.

[ScottG]

Have they tried taking some car polish (like Turtle wax) to it and really rub it in?

[dockmasterdave]

Are you sure that is aluminum? Looks like a fiberglass sided unit.