rust from roof

[yycwrangler]

IMG_1247 copy.jpg (420.54 KiB) Viewed 4179 times

Hi Guys

All aluminum trailer from Neo..This year I'm starting to see these rust marks..Have used CLR, vinegar, mr magic sponges, goo gone..Hoping I don't have to sand the aluminum..Any product you think would remove this. Sorry the pics are so large

Cheers
Al

[domoarigato]

Have you tried gutter black streak cleaner or rv black streak cleaner?

Aluminum oxidizes, but doesn't rust.. forever and ever, Amen.

[hankaye]

yycwrangler, Howdy;

NO sandpaper! Use Scotchbrite pads, over a dozen years of corrosion control for aircraft.

Have you tried gutter black streak cleaner or rv black streak cleaner?

Aluminum oxidizes, but doesn't rust.. forever and ever, Amen.

These can/maybe work, if not then try some Comet or other brand of cleaner. Warning,
once you break the protective coating that is on the Aluminum you will be chasing the
crud forever or until you sell it to someone else. One good way to prevent new corrosion
from forming would be to cover it with something like a paint that would also repel the
Sun's heat. More then a few here have used Henry's Tropical white with excellent results.
https://www.homedepot.com/p/Henry-0-90- ... /206030020

Only a recommendation to consider.

hank

[yycwrangler]

thanks guys..I'll give both those suggestions a go.Once I clean it I was hoping that I would be able to apply a wax coating for aluminum to prevent it from occurring again..Would that be a pipe dream??

Al

[GTS225]

Rust? From an "all aluminum" structure? Is it actually reddish-brown iron oxide? If so, maybe they used steel-bodied rivets?
Might be something to look into.

Roger

[tony.latham]

I keep looking at that odd-colored stain. It's not the right color for oxidized aluminum.

It is only coming from the sealed edge. I'm wondering if it isn't a reaction between the sealant and the aluminum.

Is that stuff silicone? Most silicone sealants contain acetic acid which eats aluminum.

Are the top fasteners steel? Can this be from a galvanic reaction?





Tony

[yycwrangler]

Hi Tony

Thats an interesting question..I, like you, feel that the leak is coming from the top of the trailer. When I look at the top of the trailer (will get a pic) would I be correct that the rooftop is created with a sheet of aluminum and then the roof and curved edge is covered with sealant..Are you thinking that the rivets that mount aluminum sheet the roof to the frame might be steel which are now rusting.

Al

[tony.latham]

Are you thinking that the rivets that mount aluminum sheet the roof to the frame might be steel which are now rusting.

I'll just come out of the closet and say it, I don't know what's going on. I would think if it were the fasteners, the stains would be pointing back at them.

I'm still wondering if it's the sealant that is reacting with the aluminum. Whatever it is, it'll be a re-occurring problem until the underly issue is corrected. Perhaps it's a patina you might have to live with.

Me thinks. But again, I don't know what's going on.



Tony

[yycwrangler]

They tell me the sealant is called manus bond and the screws the hold the sheet to the roof are steel with zinc plating

[foxontherun]

If you park the trailer under something like the eave of your house could run-off from the roof falling onto trailer be the possible cause of the rust color? Just a thought.

[yycwrangler]

no I was up looking at the roof today and it seems every place I have a streak there is a screw covered in the waterproofing material of the roof..Regardless, today I took some steel wool and suprisingly the rust did come off..I've followed with some meguirs aluminum polish and the front looks 100% better

[Grummy]

I have a 2018 amerilite aluminum trailer. Though "screwless", all the trim was held on with zinc coated screws. Not of any benefit....

I took them all out and replaced with stainless. Not that expensive when you look at the long run.

[hankaye]

Grummy, Howdy;

So, you removed the screws with a protective coating that help prevent the formation of Galvanic
corrosion and replaced them with un-coated screws of steel that will with the help of the Aluminum create
the aforementioned Galvanic corrosion.

Hope you still have the Zinc-chromate covered screws and have some zinc-chromate paint to renew the
coating as it most likely came off when you removed them to restore the corrosion protection to your
trailer. Otherwise the integrity of your totally sealed up trailer will be compromised within a year or less.

hank

[aggie79]

Found this on the internet:

The general principals discussed here are that aluminum and stainless steel are not actually galvanically compatible because they have significantly different potentials, but the passivity of both can reduce the problem to non-problematical for non-critical applications if the area of the aluminum is greater than the area of the stainless steel (stainless fasteners on aluminum architectural features usually aren't a significant problem, but aluminum pop rivets on stainless steel sheets would be).

Hope that clears things up.

In the practical world, my ten year old teardrop has the aluminum sheets and aluminum fastened to the plywood shell using stainless steel screws - see the seam line above the tail lights and license plate bracket/light.



I haven't seen one spec of galvanic corrosion, but granted I don't live in a wet area.

[flboy]

That is one fine looking retro teardrop. Did you build that?

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