Surface rust behind the rear arches

st185.rc

New member
Over the weekend I took the boot panels out and found some surface (hopefully) rust behind the wheel arches. The left one seems to look worse and there were some drops of water inside it (after I washed the car). By the looks of it I think the water came from under the plastic duct that goes somewhere under the rear bumper.

Couple of questions:
1) what is the best way to treat this? it's a bit difficult area in terms of access.
2) there seems to be some sort of a rubber drain pipe that goes through the chassis to the outside on the left side behind the arch - where does this drain come from? Sunroof?

TIA
 

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The tube coming through that area is from the sunroof (assuming you have a sunroof). Those tubes can get brittle & crack with age - so you need to make sure your source of water isn't from a cracked drain tube, or possible a plugged tube (where the water at the sunroof has no place to go when it pools, and then it will run down inside the body).

How to treat? Assuming you are asking what you can put on to prevent further rust? If it wasn't at a location where multiple panels come together, POR-15 is a very good coating to stop rust from continuing. But you can't get any coating in between panel seams. Once started, you really can't stop that. Best bet is to take it to a body shop and show them and ask what they would recommend.
 

st185.rc

New member
I used POR15 in the past and instructions say that you need to degrease first, then apply their Metal Prep, then rinse it down with water and finally paint. Not sure how I can rinse it in that area and then dry.

There is another product FE-123. They say just apply it and let dry. No rinsing required. And it can penetrate into the seams. Would this be a better option?
 
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