Rear panel rust, why is it so?

[conozo]

I'm talking about the rust most of us have in the rear wheel panels. does anyone know where it comes from or the water comes from that starts the rusting in the first place.

[kentwat]

Mine came from Montana salt on the roads back in the 80's. If your sunroof drains are messed up the water could leak down through the quarter panel.

[89HatchbackLxi]

I'm talking about the rust most of us have in the rear wheel panels. does anyone know where it comes from or the water comes from that starts the rusting in the first place.

Salt on roads. Water trapped in the wheel well trim cover on the top of the wheel well. Not enough protection on the front of the wheel well. My Car came from Massachusetts. I recently had to put a patch panel in on my hatch because it was rusting pretty bad on the one wheel well. Thankfully, I live in the desert though so the rust probably wont return in my lifetime, haha.

[gp02a0083]

89 hatch is right, when they made these cars they didn't form the pinch weld that bonds the inner and outer 1/4's well. In addition to the rubber trim that acts as a guard for the pinch weld lip retains a lot of dirt and water. This causes the pinch weld to rot out. Best thing is to remove the rubber lip and clean the area out and seam seal and undercoat it.

[conozo]

Thanks that explains a lot, I took that rubber trim off long ago and sprayed additional undercoat there. I think that's why I don't have a lot of rust but it's still more than I like. Someday after my current project I'll fix all the rust and wanted to make sure it doesn't happen again that's why I asked.

[Dr_Snooz]

Haven't seen you in forever, Conozo. Where you been?

[conozo]

Raising 2 kids and running a business doesn't leave me a lot of spare time for myself to work on the 3G or visit this site. All is well though and this summer I'm going to finish what I stared two years ago, carb to fi conversion.

[w261w261]

Our cars certainly aren't the only ones with the rear wheel arch rust, most Japanese cars through the 90's had it. It might be the steel, because all my German cars after say about mid 80's never had the problem.

I noticed that our cars have this putty-like substance in back of the sheet metal over the arches, about 2" up. I think this stuff absorbs moisture, and sits there like a wet sponge against the metal. Rust is inevitable.

I have two new arches in my garage. Hopefully, in the next 6 months I'm going to have someone weld them in after cutting out the rust. It's kind of a big job to do right, and not real cheap, so I'm struggling with the rational of the cost, including the repaint. But I bet that will fix the problem.