Floor panel rust

[Supertim]

Hey guys,

So today I removed the carpeting from my recently purchased 87 325is. Initially, when disconnecting the gas pedal it came out with a tonn of rust, which made my heart drop.

Picture:


Then, after an hour of carefully cutting the carpet to avoid cutting cables and hoses, I was able to remove it and BAM - I thought I stroked out or something :eeek:, aside from the word "f**k" there was nothing I could say :neutral:

Picture is worth a thousand words:



Naturally my mind tells me welding, but I have never welded anything in my life, and 4 days ago I soldered my first wires together (I am in IT by profession, programmer by night, and a driver at heart). Not a lot of hands-on experience. Guys - what do I do, how, and how much will it cost me?

Note that I am not ready to hear anything about scrapping the car so please lets hold off on those remarks, at least for now. Thanks.

[jlevie]

It doesn't look like it is rusted through anywhere, which suggests removal of loose rust, conversion of the remaining rust (think Naval Jelly or similar), and coating with two part epoxy paint. Possibly followed by a layer of fiberglass, depending on how damaged the area is.

[Supertim]

Thank you jlevie. I just looked up Naval Jelly and it looks like it dissolves rust. I heard about substances that can convert rust back into steel - did I understand wrong or is that what you meant by something similar to Naval Jelly?

In other words i would sand it down, apply the substance in question (which would eliminate rust in any case), coat it with two part epoxy, and depending on results add a layer of fiberglass?

Indeed there aren't any holes (yet) but I'm afraid that it may be too easy to break a hole in it, given that by attempting to remove the gas pedal alone I took out a decent chunk of rust :(

Once again thanks for the reply because I'm having a hard time keeping a cool head around that much rust, and my lack of experience leaves me expecting the worst.

EDIT: would something like POR-15 be a good idea? http://www.por15.com

[Supertim]

jlevie,

I did some more research and all these items are basically the same thing. They don't covert rust into metal but they stop rust from progressing and give a foundation on which to attempt repairs (pretty much exactly what you suggested, but you provided valuable, specific details).

Am I right?

[SubDad]

It's gonna be OK...

The pictures don't look that bad, honestly.

It is bad enough though that I think it'd be worthwhile looking everywhere for rust, including removing all the seats and carpet, then treating what you can with a rust converter. (Put it on ramps and look underneath, too.) Once you get started it takes about an hour to see all the floor. Go ahead and chop up the carpet, then with your new interior gutting skills get a full carpet out of a junker.

Look to the left of the gas pedal - I bet it's actually worse near the door post and against the inside of the rocker than under the gas pedal. The places where the front jack pads meet the floor are apparently notorious.

My first E30 was way - waaay - worse than that and I found a welder to fix it up and make it strong for $1200 Cdn.

Making a new gas pedal hinge will take some ingenuity.

[Supertim]

SubDad,

Funny you say that - because that is exactly how I discovered the rust. I took out the interior carpets completely. Everything was looking great up until I got to the gas pedal and then I knew that its not going to be pretty. The remaining parts of the floor panels are OK.

You are also correct about the rocker panel area - though I'm not sure if it is the rocker panel or the fender that is rusted through. Here are some pictures (driver side front fender area, right where it meets the front door):



And a close-up:



Thank you for your comment - hearing about other people's problems being way worse comforts me in an odd, humanly way :) Glimpse of hope!

[SubDad]

Here's what mine looked like before welding.
I don't have any pictures of post welding. It wasn't prettier, but it sure was stronger.

Under the right rear corner of the back seat there's a tube that often rusts. And how's the right rear shock tower where the filler neck attaches?

[Supertim]

Wow I can't tell which side is worse :| did your welder cut the panel out and weld sheet metal in its place? I haven't checked the shock tower from the inside, I'm yet to gut the trunk and remove the back side of the rear seats. I'll do it tomorrow, almost don't want to know whats happening there.

I did some cleanup today and things aren't so good. So I used a set of wire brushes, sandpaper and all that goodness to remove as much rust as I could and the damage is this: the rubber plug to the left of the gas pedal fell through since whatever held it in the floor pan simply rusted away. Underneath that plug is some housing that is also rusted and there is a small rust hole revealing the cement floor of the garage. So that there is a round hole lol.

Not so bad when you compare it to a larger hole underneath the gas pedal - so if yesterday I thought that there was a place to fabricate gas pedal clips - now there isn't. The other area (blue in the picture) I can't say much about. I couldn't see any metal under the rust and hitting it didn't create any punctures so its tough to tell the extent of the damage. I can try using epoxy and fiberglass to create a makeshift panel under the gas pedal so I could drive to a shop but that's probably as much as I can do on my own, at best.

Picture is worth (another) 1000 words:

- Red circle is a hole
- Red rectangle is hole that is magically held in place, but that's just magic. The whole thing is falling through I just didn't want to tear out the point that may hold my fiberglass/epoxy solution.
- Blue is unknown condition, couldn't brush away all the rust, it makes a dull sound when you knock it, and is most likely going to become a hole as well.

[AndrewBird]

Poke at it with a screwdriver or pick and see if it pushes through anywhere. All the holes will need to have new metal welded in. Fiberglass is a bad way to fix it. Water can get in under the fiberglass and cause even more rust. It is used by body men who either don't know what they are doing or who want to cut corners and do it the cheap way.

You might get away with cutting out the bad parts and using body "glue" to glue on new panels. Lord Fusor is a glue used for this type of thing. I've seen it used to glue entire new floor pans in place, so a few small patch panels should be fine.

First thing to do though is clean everything up and see where you stand. A wire wheel in a grinder or a drill will be your best bet. Take everything down to clean metal.

[Supertim]

I DIDN'T EVEN THINK OF A WIRE WHEEL! That is genius, human arms just don't cut it anymore :p So I'll grab my dremel, get the bit and that should help a lot.

I was going to use fiberglass as a temporary solution just to be able to take it to a shop but this may actually be something that I can do on my own and can last me a little while.

A friend of mine has a DeWALT reciprocating saw and he said he can let me borrow it so if I can find some spare sheet metal at work that can do the job I might just cut it to fit the area in question, and glue it using LORD Fusor. I could also try using LF to create makeshift clips for the gas pedal, which I can place directly on the sheet prior to gluing on the floor panel.

That sounds like something I could do (or try) and is very reasonable! :bow:

I understand the LORD Fusor is some strong stuff but will I be able to remove it later when I'm ready to weld a more permanent repair? Do you think it will work for the gas pedal clips?

[SubDad]

What NRD said: Hammer at the suspicious looking stuff and if it falls away you didn't want it anyway. If it stays it's good stuff. All due respect to jlevie (and I do respect his answers, 99.99/100), but fibreglass won't do the job for long, for the water infiltration reason that NRD mentioned and because it's not structural. When something hits you you'll be glad that you retained the welded steel structure. Polyurethane seam sealer is best for stopping leaks.

The guy that did the welding on my car put a new floor *on top* :eeek: of the old. If I had known he was going to do that I would have stopped him, or asked him to connect the two better. On the other hand, by raising the floor half an inch he was able to pick up good steel at the rocker frame. On the other-other hand, there are two major structural rails under the floor and he just sort of ignored them. If I still had the car I'd be getting brackets made to join the floor and the rails.

Waah! No saws! Well, sure, cut panels to fit the floor, but you wouldn't use the saw on the actual *car*, would you?

[SubDad]

I spent so much time agonising over my floor that I'm re-living the whole nasty episode, thanks to you ;)

How about:

-/ Not doing a temporary repair at all, but rather:

A/ beating, pounding and poking until you know exactly what the scope of the problem is, then,

B/ bolt in one seat and drive around from welder to welder until you find one that has a plan that makes sense and that is affordable.

I'll be wanting to know how it turns out, too. With pictures!

[Supertim]

No I wasn't planning to use the saw on the car itself, but now that you mention it... :) Just kidding. I'm too worried that I may cut something behind the floor panel, if anything I'll make the replacement panels slightly larger than existing holes, rather then cutting. The trick is to get all the rust out and cover with Naval Jelly to prevent future corrosion.

I'll beat it until all the rust is gone but to get from welder to welder I will need a gas pedal, no? ;) Or at least some place to put it, like a floor or something haha. Temporary solution in my book will have a lifetime of no more than a week, two at most, and that's for a weekend driver, not DD. I have already gone too far not to post pictures of the solution (and progress). It's the least I can do.

Sorry about triggering your flashbacks, if you feel/felt anything like I feel then I offer you my sincere sympathies :-|

[SubDad]

Naah, you don't need a pedal, just long shoes. The throttle link connects to the top of the pedal and with pedal out of the way it works just like normal, if your foot's long enough.


A Bad Story:
After he was done the welder I used screwed the gas pedal hinge back to the floor with sheet metal screw, then called me in a panic to say that the (Italian accent here) windows they not go up and it's raining.

No probs, said I. Picked up the car. Gas pedal falls off upper link, but still trapped to floor, sort of in the way. Gear shift won't find first - console with window switches in the way.
Windows and sunroof open, cold rain falling, red light in middle of hill. Hand brake not working. Held the car in middle of hill with desperate stabs at clutch throttle and brake, some of which would sometimes work. Clutch smoke mingles with rain. Welder forgot to bolt seat down at front.
Giggling started, hasn't really stopped.

Happy E30!

[Supertim]

can't stop laughing!