My Doors Are Rusting Again ! Anyone got a good fix ?

[Derek A.]

The last time around I wire brushed the doors down to bare metal. Used a zinc based self etching primer, went over that with paint. I then put new rubber strips on the bottom with silicone to seal them off. I now have the rust back again. Looking for suggestions on how to repair this problem once and for all.

[TimGinCentralNJ]

...but last Fall, I went through this myself after reading this was a common problem with the E34. After pulling off the strips from all 4 doors, turned out only my driver's door had any rust, so I lightly sanded it and applied a few light coats of POR-15, followed by a thin top coat of Chassiscoat black (same company -- no affiliation). I haven't seen any rust, however, I also never reinstalled the rubber strips either. Seems they're good at trapping water in there.

Anyway, I've used POR-15 on old rusty floorboards of my old jeep, and a handful of other auto and non-auto applications, and I've yet to see any rust return. Just my $.02....YMMV.

Hope that helps,
Tim G.
'91 535iM

[jplacson]

I have some rust spots on the inside of my trunk, on the sides, behind the side carpetting... how do I get rid off these spots? Would it be recommended to weld a new piece of metal over this part to reinforce it after the rust has been sanded off?

[winfred]

move to the south or somewear without road salt, sell rusty bimmer and buy local non rusty e34, never think about automotive cancer again, live happly ever after

[632 Regal]

Silicone attracts moisture big time! Ever see people put it around windshields to stop them from leaking and the next year the whole window falls in? It's from the use of silicone. Use something else like urethane to fit the rubber back up there after you fix the rust. Also let the paint and primer "breathe" out for a couple weeks before you lock the vapors in with a sealant.

[winfred]

yep, it's fun when somebody silicones in their tail lights, after a couple years you just push em out the bolts are just for looks

[jplacson]

Does anyone have any experience with Ziebart Rust Treatment? I'd like to have my spots done, but I was told that their rust proofing screws up BMWs coating. Any comments on Ziebart Rust treatments (the one that turns rust into some harmless compound)? Thanks!

[Paul in NZ]

there are many product for this but i cant think of one.....check out your local hardware store, "anti rust" primers will include a reference to some prior treatment.Remember.....rust never sleeps

[632 Regal]

cant sand it prior or after treatment or it wont transform it. If it has rust pits to do it correctly you have to use an acid wash to get the rust out but make sure to wash all the acid out (baking soda) or you will paint the rust and caustic acid in there which is not good (ask my old 57 Dodge that I gave away to a good home)

[winfred]

the car disolved did it