What is the Goop they Put on the Fender Wheel Well

[Mark_BC]

There is some minor rust on the edge of the inside lip of the fender in the wheel well. It has travelled between the metal and the rubbery stuff they slathered on it. So I will remove the goop in that area and repair the rust, then I'd like to put some more of that rubbery goopy stuff on to protect it from rocks. Does anyone know what this is or have an alternative?

 

[spartacus]

There is some minor rust on the edge of the inside lip of the fender in the wheel well. It has travelled between the metal and the rubbery stuff they slathered on it. So I will remove the goop in that area and repair the rust, then I'd like to put some more of that rubbery goopy stuff on to protect it from rocks. Does anyone know what this is or have an alternative?

it's roll on truck bed Monstaliner.

 

[Scramble]

The Black stuff an undercoating. Usually a spray on rubber. They also put seam sealer between body panels/spot welds to keep water out of the cabin.
Not sure which one you're talking about. But they are both a ***** to remove. I use a wire wheel on a drill. Eastwood has a rubberized spray undercoating thats also a rust encapsulator. Check out their site for rust solutions.

 

[Kanoe]

Depending on where it is, it could be a version of this stuff. This was a very good match for some spots that needed sealing in my corolla due to a previous accident.

 

[Mark_BC]

Here it is. You can see at the bottom the goop separated from the metal. I'll remove that goop somehow and bring it all back to clean metal. Then I'll paint it up thick with multiple coats. I was thinking I'd put bondo all over it but it would be nice to have something flexible. Maybe caulking instead, or that stuff Kanoe recommends. Monstaliner isn't flexible right? Also I want to be able to see if it starts rusting again. Monstaliner would hide that.

Also there was rust bubbles forming on the holes for the fender flares so I need to clean those up.

 

[Mark_BC]

So it was the pinch weld that was separating due to the rust. I used my dremel and got rid of the rubbery goop fairly easily and ground out the inner layer of metal. I went through in a couple places but no big problem. I'll put some bondo in there to re-form it and give it some meat, then then fill in the area with silicone. Then paint it several coats.

Also I checked inside my rockers and they are rusting again!!! I went through all the effort to soak them with Ospho then several coats of spraying in Eastwood Frame Paint, and then after one day of driving on the Oregon coast with rain and salt spray, it all starts rusting through again!!!!!

Screw this frame paint, I'm just going to use Fluid Film. On accessible areas underneath I'll remove all rust and properly paint. Also I might use Por15 in other areas.

 

[97t4r81]

There is also a 3m epoxy fender product that comes in different flavors depending on application. My body & fender friend uses instead of bondo or patch panels in your situation. It is more flexible that body fillers, but can cover more than seam sealer. Find a paint and body supplier local and ask about options. Undercoating is last if at all. My .02. Best to ya

 

[josh8991]

I am having the same problem - the rear fenders are rusting on my recently purchased 2000 SR5 4runner. I've started to sand/cut out the rusted through areas and noticed that the wheel well metal is rusting through as well, what would be the fix for this? Cut out the affected ares of the wheel well and weld in new metal patches? Sorry not sure how to upload pictures on here.

 

[brillo_76]

I am having the same problem - the rear fenders are rusting on my recently purchased 2000 SR5 4runner. I've started to sand/cut out the rusted through areas and noticed that the wheel well metal is rusting through as well, what would be the fix for this? Cut out the affected ares of the wheel well and weld in new metal patches? Sorry not sure how to upload pictures on here.

That's what I do. I either weld or glue on patches. There is a panel in the rear wheel that is very thin. It rusts out alot faster then the rest.

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