w123 Floor Rust repair - Page 8 - PeachParts Mercedes-Benz Forum

vwnate1 · #**106** 04-23-2021, 10:16 PM

Looking good to me .

martureo · #**107** 04-24-2021, 09:40 PM

New metal bit by bit.

martureo · #**108** 05-06-2021, 02:09 PM

Well, the saying holds true; where there's rust, there's always more rust.

Before I started closing off the interior of the passenger's floor I wanted to pinpoint the location of water ingress that caused the rust in the first place. After I located a few points of suspicion in the battery/firewall area I found some rust in in the inner fender underneath the wheel well liner.

I've applied a filter in this photo as the rust was kinda hard to see, especially in the noon sun. Its the boxed in section.

Well, that means that I'm going to have to remove the fender to get at that. I knew there was some rust in the lower corner of the fender and I'd better take a look at it before I go removing the fender. It'd be much easier to tackle any patch repair with the fender secured to the car.

Ok, well that's more rust than I remembered.

What's it look like with the rubber trim off?

martureo · #**109** 05-06-2021, 02:12 PM

Well, crap. The last mounting bolt for the rubber trim mounting plate came off in my hand, along with part of the fender.

Wonderful. Now can I at least get the nut and reinforcement plate (part of the fender) off of the bracket?

Nope. The stud sheared off.

martureo · #**110** 05-06-2021, 02:20 PM

Ok, I've got to salvage something productive out of this time I've got to work on the car.

Lets see where the rust stops.

For comparison, below is where we started.

And here's another angle.

Right now I'm in between just going for it and finishing it up when I remove the fender, or just getting another fender.

There's pros and cons to each, but here's my thought process.

-I don't know what other rust is on this fender
-It might take a long time to make it just right, and the bracket for the rubber may never be up to par
-But the entire repair is going to be hidden under the rubber and out of sight

On the other hand, getting a new fender:
-might give me a rust free part to put on the car without much effort
-will have to be painted, and will most likely look better than the rest of the car until I get a full respray
-might be something hard to find without needing a bit of body work (dents)

Not sure yet. But this was a definite blow to morale.

vwnate1 · #**111** 05-06-2021, 02:45 PM

I see no evidence of heat nor penetrants used to it's natural the mild steel 6MM stud broke off .

That's not a problem because this is common and I've seen longer 6MM bolts used with flat washers to fix .

I'd replace that fender if at all possible .

You'll be *much* happier and done faster replacing the entire fender .

martureo · #**112** 05-10-2021, 09:47 AM

Well, yeah. I'm gonna get a new fender. I decided to inspect the other mounting points just to make the rust was confined to the corner previously pictured. It wasn't.

And this too wanted to play hardball. That rusted out area of the fender didn't want to come off the car and the screw didn't want to come out. So it left a nice gaping hole in the fender. (Screw did come out with vice grips)

Now that a new fender is going to be on its way, lets get back to where we were going to work in the first place. Doesn't look too bad on the surface.

martureo · #**113** 05-10-2021, 09:51 AM

Rust probing tool? Check.

Well, poop. There's more than I thought.

I learned my lesson on the other side of the car and decided to remove this outer panel which creates the outer side of the hinge pocket. It looks like a huge piece to remove, but was really easy to cut through a few stitch welds and drill out four spot welds. This will give me more access and more confidence that the water is going to stay out of the foot well.

Just wanted to show this so that someone else can see where I did it.

martureo · #**114** 05-10-2021, 09:55 AM

Its been said before and I'll say it again. Clean your drains!

This car has been daily driven for going on eleven years now and I thought I'd done a decent job cleaning out these hinge pockets, but turns out there's a layer of silt and crap still sitting in the bottom of them.

After cleaning all that up and cutting until I reached metal, there's a nice big section that I'm going to have to patch. But at least I'll know that the water will stop coming in the cabin after its done.

vwnate1 · #**115** 05-10-2021, 10:19 AM

How does one go about releasing the glue along the upper edge of these fenders ? .

TIA,

Mike D · #**116** 05-10-2021, 10:26 AM

Heat gun.

vwnate1 · #**117** 05-10-2021, 11:02 AM

Will a hair dryer work or do I need to go buy a real heat gun ? .

Mike D · #**118** 05-10-2021, 03:02 PM

I've never had any luck using a hair drier to loosen the glue but you're welcome to try.

If you are replacing the fender anyway, and have a spritzer water bottle handy, a propane torch works even better.

I use a heat gun because it is easier to control the heat.

martureo · #**119** 05-10-2021, 03:57 PM

Quote:

Originally Posted by vwnate1

How does one go about releasing the glue along the upper edge of these fenders ? .

TIA,

As far as I remember, it was only the early w123s that had the fenders glued on. Neither my 84 or 83 were glued on and came off pretty easily by just removing the fasteners.

Clemson88 · #**120** 05-10-2021, 10:27 PM

After studying this thread I quit feeling sorry for myself for having to cut out and small rusty strip (8"X2") and I'm felling good about it. Never mind that it's just above the bumper cover behind the right wheel well.