w123 Floor Rust repair - Page 6 - PeachParts Mercedes-Benz Forum

gonesurfing · #76 11-17-2020, 11:27 PM

I'm all too familiar with this repair. LOL.

martureo · #77 11-23-2020, 11:22 PM

Not much of an update. Just a few more patches.

This one was frustrating to photograph. Most of this is bare metal and of the few shots I had of it, this was the best. Too much reflective surface doesn't make for good pictures with a camera flash.

It doesn't look like it, but it is nice and smooth. It'll look better with paint on it.

This one was a bit exciting as it means that the driver's floor and rocker panel are now solid. No holes left either of rust or of cut out sections.

martureo · #78 11-29-2020, 03:29 PM

It seems like there's always another patch to be made.

I thought this area was solid, but after shining a flashlight on the back side of an adjacent area to check for pinholes in my welding, I spotted a pin hole here. So I ground back a bit more of the paint and found plenty of rust on the back side which thinned the wall. Couldn't see it from this side and when tapped it sounded solid.

It went from a pinhole to this.

Because of the placement of the new patch going into the firewall area, I still wasn't confident that the welds would seal it properly and wanted to verify from the other side.

I don't care as much if my hinge pocket/fuse box drain leaks into the wheel well, but I do care that nothing leaks into the passenger compartment.

So the original cuts I made to access this leak and the red areas that I ended up cutting out.

After cutting the patch which rounds the corner and seals the firewall from the drain and the sidewall, I ground back all the welds as best I could and checked for any missing spots/pinholes. I ended up having to use a hand file to smooth the welds in this area as my die grinder wouldn't fit.

As you can see, the hood release cable hole is bisected by the patch. I didn't remove the cable while welding this in and damaged the jacket a bit. I don't think I'll need a new one, but we'll find out soon enough.

Sorry about the picture, but I couldn't get the lighting right and after six attempts this is the best I got.

martureo · #79 11-29-2020, 03:39 PM

Paint has come out, so things are really getting serious.

I'm using the Rust Encapsulator Plus on the inner fender, two coats. I used silver POR 15 that I had in my own garage to paint the inside of the fender, so anyone looking up in the wheel well later will get a nice surprise.

(sorry that this shot sucks, something with the lighting in the shop recently has been messing with the camera on my phone)

After the paint dried a bit, I felt confident enough that I was finishing up this section that I cleaned up the larger cut out section and welded it back in.

Oh it welded so nicely. Much better than the patch panels I've been working with this whole time.

martureo · #80 11-29-2020, 03:45 PM

On both the passenger and driver's side, the outer front seat mounts had rusted through. I tried to save the passenger's side one and use it as a template to create a new bracket.

(done a few weeks back)

The biggest problem I had with mounting it back in the car is the placement. I dunno about you, but I already have enough fun putting w123 seats back into the car when everything is stock. I really didn't want to have to fuss about with a seat mount that was in the wrong position.

So I used my wagon as a model and created this lovely jig from 1/2" bars of mild steel and pop rivets. (welding would have been easier, but someone's using it at a shop somewhere...

)

And here it is in place ready to position the bracket.

martureo · #81 11-29-2020, 03:47 PM

Unfortunately, that repair is going to have to wait until I can get back to the shop as I ran into the nicest problem I've ever had with my welder.

An empty spool.

Mike D · #82 11-29-2020, 05:52 PM

When you replace the wire, try using the Inefil brand. The Lincoln stuff is "okay" but the Inefil lays on much smoother.

moon161 · #83 11-29-2020, 05:55 PM

If you're replacing both front and rear seat mounts I would weld the front in, bolt the seat on and use the back end to spot and tack on the rears.

martureo · #84 11-29-2020, 07:49 PM

Quote:

Originally Posted by Mike D

When you replace the wire, try using the Inefil brand. The Lincoln stuff is "okay" but the Inefil lays on much smoother.

I'll have to hunt some of that down. I just picked up another spool of the same stuff as Home Depot was open when I needed it.

I ordered some stuff from McMaster awhile back but they sent me the wrong stuff twice, so I gave up. And the local Robert's Oxygen shops have terrible hours.

martureo · #85 11-29-2020, 08:12 PM

Quote:

Originally Posted by moon161

If you're replacing both front and rear seat mounts I would weld the front in, bolt the seat on and use the back end to spot and tack on the rears.

The inner rear mounts on bots seats are good (I've been using them as grounds for the welder).

The front channel on the driver's side was completely removed.

So the jig is for the rear outer passenger mount, the driver's outer rear driver's mount and the front driver's channel.

Mike D · #86 11-29-2020, 08:35 PM

For solid core (flux) use the Inetub line

For shielded (mig) use the Inefil

https://www.weldingmania.com/mig/best-wire-gmaw/

j-galap · #87 11-29-2020, 10:40 PM

Just read through this whole thread. Keep up the good work - it's impressive! Wish I had a garage to work in and not just the side of the road

martureo · #88 11-30-2020, 08:08 AM

Quote:

Originally Posted by j-galap

Just read through this whole thread. Keep up the good work - it's impressive! Wish I had a garage to work in and not just the side of the road

Me too!

I have a garage at home, but if there was nothing in it but the car, I couldn't open the doors without hitting the walls.

I rented a bay in a guy's home garage for a steal. ($300 a month) But as COVID screwed the timeline on this one, he needs the garage back. I'm pushing to get this done ASAP.

moon161 · #89 11-30-2020, 01:12 PM

Quote:

Originally Posted by martureo

The inner rear mounts on bots seats are good (I've been using them as grounds for the welder).

The front channel on the driver's side was completely removed.

So the jig is for the rear outer passenger mount, the driver's outer rear driver's mount and the front driver's channel.

Unusual in my experience, usually first to go is outside rear mount. You learn to tug on the seat when assessing a 123 body.

In the same way I'd reverse it instead of rely on measurements. Let the seat mounted in the rear be your fixture for the front.

martureo · #90 11-30-2020, 10:12 PM

Quick update.

Started forming a few patches to close in the holes in driver's inner fender after spending 20 minutes fiddling with the hood release cable grommet. Then moved on to prepping the driver's floor for the driver's seat support channel.

Back and forth between drying primer and shaping patches led to only one thing being completed before I called it quits for the night.

It is in!

(greyish paint is weld thru primer)