Use "Tiger Hair" Putty or Weld to repair some rust damage.(85 300D).
 

I've got some rust breakout around the outside edges of my rear wheel wells of my 85 300D. Part of me says try to get it welded, and the other part says just use the Best Putty you can find to repair it. I eventually hope to restore this car to NEW or near new, but cost is a consideration.

PRO's/CONs Welding: I have heard that welding on Mercedes 85 300D is not so good because of high lead content of stelel and in the end you need Putty anyway to finish it...

PRO's/CONs Putty: Putty always breaks out in 5 years, which is how long I have had this car.

you have to cut the rust out...if you don't its going to be ten time worse in a very short time....


You treat rust like you would treat cancer....


if the car already has terminal cancer then by all means bondo away to keep it looking decent till its ready for the crusher....

I would cut and weld. I have seen jobs done where the rust was cut out and new metal "glued" in, however I would not recommend it.

What I've started (and plan to finish soon - really!)

1. Cut out rust (within reason)

2. wire wheel/strip back a little

3. Weld in new steel behind the hole

4. Treat with a phosphoric acid solution

5. Coat the new and pitted steel with Rust Bullet

6. Fill with short strand fiberglass filler to contour

7. Prime, paint, clearcoat and compound

I'm at steps 3-4 now, we'll see.

Why not?

I have seen jobs where the rust was cut out and new metal was "glued" in.

I was perfectly satisfied with the result, and have been for 3 years.

I used Fusor 12B 2-part epoxy on the lower rear corner of the rear wheelwell arch. I "fused" a complex shape of about 5 pieces including flat patches for the trunk floor. I used a very minimum amount of kitty hair fiberglass to get a good contour. You can't tell it from the original.

I used it to patch small holes in the floor. I have some much bigger projects in mind for this stuff.

The beauty of it is that it does not induce corrosion like a weld would.

Rick