RUST: WW Chad300tdt D?

[Bengoshi2000]

So I went on the search for rust yesterday and pulled the plastic front wheel well covers. Driver's side looks great... passenger's side, not so much. Here's what I found:

Looking great up towards the battery tray... but you can see the rust on the left above the rubber plug:








My primary concern is that this is a structural area and that a proper cut and weld approach would be best. So what would be the best plan of attack?

Chad300TDT... are you still out there? Your posts on repairs in this area are legendary!

[StaggerLee]

Try him in the Body work forum.

[charmalu]

Hopefully you found it in time and it hasn`t rusted all the way through.

you will need to remove the fender to do the job.

I have used Jasco paint stripper to soften up the rubber under coating MB used. then you will be able to cut through it to get back to good metal. you need to see how far under the coating the rust has gone.

I use POR products, and would wash it all down with their Marine Clean to degrease everything.
Then once you have the undeseal and paint removed, treat it with their Metal Ready. It etches new metal and will disolve the rust given enough time.

when you have it all prepared, then coat it with their POR paint. just follow the directions.

that area behind the fender and splash shield it a breeding ground for rust. it never gets looked at by the majority of owners, but us a breeding ground for rust. It should be washed out every year.

Just about every 123 I have looked at in this area, my own and one`s at PNP. all seem to have this problem. seem MB didn`t address this area from the start when the cars were built. In most cases it looks like the wall area didn`t have much more than a coat of primer on it.


That area under the Battery tray area can really be a nightmare to fix. there are several body panels that come together there. plus the hinge pocket drain etc.... get neglected and will rust through.

My 85 has this problem from the battery. and rusted through into the cabin. didn`t know i had a problem until I was scrapping around and the screwdriver went through the sheet metal.

After I treated it and painted the POR, i used their thin fiberglass matting soaked with the paint to seal and bridge the areas. then used their seam sealer to fill the voids and smooth it all off.


Charlie

[tbomachines]

Originally Posted by charmalu

Hopefully you found it in time and it hasn`t rusted all the way through.

you will need to remove the fender to do the job.

I have used Jasco paint stripper to soften up the rubber under coating MB used. then you will be able to cut through it to get back to good metal. you need to see how far under the coating the rust has gone.

I use POR products, and would wash it all down with their Marine Clean to degrease everything.
Then once you have the undeseal and paint removed, treat it with their Metal Ready. It etches new metal and will disolve the rust given enough time.

when you have it all prepared, then coat it with their POR paint. just follow the directions.

that area behind the fender and splash shield it a breeding ground for rust. it never gets looked at by the majority of owners, but us a breeding ground for rust. It should be washed out every year.

Just about every 123 I have looked at in this area, my own and one`s at PNP. all seem to have this problem. seem MB didn`t address this area from the start when the cars were built. In most cases it looks like the wall area didn`t have much more than a coat of primer on it.


That area under the Battery tray area can really be a nightmare to fix. there are several body panels that come together there. plus the hinge pocket drain etc.... get neglected and will rust through.

My 85 has this problem from the battery. and rusted through into the cabin. didn`t know i had a problem until I was scrapping around and the screwdriver went through the sheet metal.

After I treated it and painted the POR, i used their thin fiberglass matting soaked with the paint to seal and bridge the areas. then used their seam sealer to fill the voids and smooth it all off.


Charlie

Funny that you mention the battery box rust spot. I had one heck of a time patching my very own battery box rust spot the majority of the day today. I cut out the rusted out metal (went into the wheel well, looks like the grommet around the brake pad wear sensor wires decided not to work), welded in a new panel the best I could. Welding there is very hard, due to 3-4 pieces of metal coming together, and there are several thicknesses of metal depending on structural significance. I made sure the welds were solid on the structural part. The rest I just used a wire brush and grinder/dremel to get all the rust away that I could. I laid fiberglass over the open wound/weld work in the wheel well and let it set. All the rust on top was hit with the brush and POR15'd. After the glass set, I sprayed 3 coats of truck bedliner, and then another 2 of undercoating after it dried. Its a losing battle with the rust but this fix should get me another 5-10 years out of an otherwise 100% perfect body.

<sick of rust>

[JB3]

I did this repair as well, replacing most of what MB had originally with similar structure as OEM. However, upon reflection, I would get rid of that stupid ledge and make it a slope to drain water and debris off, and then I would put in a couple deep drain channels so dirt does not build up there so easily. Both changes would be pretty easy to do if its all being redone anyway, and probably really cut down on rust getting started there again long term, plus be a nearly invisible change in the body.

Heres some super basic pics of what I am talking about, one on the left is the stock ledge, one on the right is the changed version

[Bengoshi2000]

Originally Posted by dropnosky

I did this repair as well, replacing most of what MB had originally with similar structure as OEM. However, upon reflection, I would get rid of that stupid ledge and make it a slope to drain water and debris off, and then I would put in a couple deep drain channels so dirt does not build up there so easily. Both changes would be pretty easy to do if its all being redone anyway, and probably really cut down on rust getting started there again long term, plus be a nearly invisible change in the body.

Heres some super basic pics of what I am talking about, one on the left is the stock ledge, one on the right is the changed version

That's a good idea... and one that I will keep in mind when I get around to this repair.

Nice use of google sketchup, btw...

[Bengoshi2000]

Would a Mod be kind enough to move this thread over to the bodywork section?