We all know that the rusting of the storage bins seems inevitable. Has anyone actually figured out what the design flaw is?
I think it is coming from plugs that fall out where the wheel well is sandwiched together with the bin. It seems that wheel wells that were undercoated are not as prone to rust.
Anyone else have a clue?

 

Elusive.

I think it's those rubber plugs plus crud/leaves/salt in the wheel wells.

 

It has something to do with the different layers of metal not being sealed right or something. It would be nice to know exactly what is wrong so when you fix it it won't happen again.

 

before you get it or after you correct it...isn't there some spray product that can be applied to prevent it from happening again? something like that spray on bed liner used on pickups?

 

There is no fool proof way of preventing rust on steel. Coatings and liners are kind of a bandaid. What happens with the bedlinger or undercoat is over time it cracks, trapping moisture under the coating. Inturn creating rust that is much worse that without the coating.

 

Yes ELUSIVE, usually I'm laughing at spelling errors. I was on my way out the door when I posted and did not proof read.
Anyway the new undercoats are softer and do not crack like the old, letting moisture in.
Has anyone ever seen a 81-85 with lots of miles and no rust? Did it have undercoat? Do 79-80 have the same problem in that area and can you check it without the bins?

 

I've dealt with this extensively on my car. The problem is with the extra metal plate that is welded on to the wheel well at the front inner corners of the outside of the car. The plate has no holes for drainage, so salt just corrodes until it eats right through to inside the car. The wheel wells are layered and aren't thick, whereas the extra plate is quite thick. I believe given the change in engineering with the welded plate that NA cars had this added for a saferty reason, but that's speculation.

To fix mine, I first chipped away every last piece of rust I could. Do't be afraid to be rough; if it breaks it's not good metal anyways. I had a hole where I could reach through and touch my rotor from inside the car. With the rust that's left I used a rust-converting chemical (One-Step which I love, or POR-15 which I'm anxious to try would work too probably) to kill the rest as much as possible.

I then used a fiber-glass mat with epoxy resin, along with the threaded fiber glass and same resin, and used the mat to cover the hole and generally goup fiber glass wherever I could from the inside of the car. It dries very hard, and then provides backing for a new (very thick) coat of undercoating. There is undercoating made to be thin, and some that's made to be thick so you gotta get the right material.

I bet my tar was 1/4" thick at least... Took a good week to dry enough to get it back on the road. But that was 5 years ago and it's still perfect under there. That's my experience anyways. As for the outside lip of the wheel well, I had less perfect results.

 

I pretty much did what Felgar did, except that I patched in sheet metal using epoxy resin and sheet metal screws to set it and create a water proof seal before covering over with the threaded fiber glass resin. Seems to have worked fine.

Ray

 

POR-15 has an excellent rust neutralizer called Metal Ready. Spray on and it starts dissolving rust. Keep the metal wet with Metal Ready, keep spraying it every 15 minutes or so.

Neutralized rust turns into a grey paste you wipe off. Keep spraying and wiping off the grey paste. Clean with Lacquor Thinner then prime.

I've used 10 gallons of Metal Ready so far on my REPU, it's the bomb! $28/gallon.

http://www.por-15.com/product.asp?productid=177

 

Another good way is to avoid winters and rainy days!

 

Funny, my non sunroof car is mint, but my others are not. Someone told me I was wrong in assuming it was from the sunroof drains. Go figure. I dunno.

 

My car lived it's life in Washington has has very little rust for an 82 with 156k miles on it.

No rust in the bins, even underneath is pretty clean. But now I live in IL, where all hell has broken loose on my car. I hate living here and cannot wait to go back to the West Coast. I still have very little rust, but there is surface rust showing up on suspension components that were virtually clean when I bought the car.