Hi Guys

I've decided to do some restoration work on my 1985 190E, and as with any restoration, there are some rust holes to patch up.

I enjoy working on cars very much, so I invested in a Mig welder, a tank of shielding gas and some fresh metal. naturally before I put the welder to the car, I spent some time practicing with different setups, and my results were quite awesome, so this past weekend, I took on the task of patching up a big hole in my baby benz.

Now like I said, I'm no expert, but I like trying new things, and since my car is in storage for winter, I can do all sorts of things with it. What I'm looking for is anyone who has any experience welding these cars. The metal is proving to be a bit tricky, and I heard talk that German steels is galvanized, mine does not look like it.

I ran into a specific problem, which I ran into on very thin metal before, what happens is as soon as I move the welding tip over the metal, it vaporizes. In some cases I expected this since rust got the better half of my car, but, it was happening a little too often. Adding some more metal cured the problem in some areas, but attaching that new metal to the old is not as easy.

Would anyone have any tips or suggestions on how to deal with this? My first patch came out not all that awful, but it was much too time consuming.

Thanking you in advance

xp

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1985 190E 2.3L - a constant project.

I can't help on technique, but one caution I want to pass on is to make sure your ground is close to the welding action. If you ground some other part of the car, you may find arcs jumping across things like wheel bearings or electrical devices. Also disconnect the battery.

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95 E320 Cabriolet, 159K

Yup, got the grounding right next to the point I'm welding, and battery is disconnected.

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1985 190E 2.3L - a constant project.

I don't know what type of welds you are doing except that you are using a MIG welder. A typical weld is a seam weld which generates a lot of heat which can melt the metals if they are thin and warp the panels. Another weld that can be done with a MIG welder is a spot weld. Drill small holes of around 1/8" in the patch near the edge say about every 1" or so. Then fix the panel in place and start welding through the holes to the panel you are repairing. Many MIG welder manufacturers even make special tips with little legs to hold the tip off of the metal with the correct clearance, and because you are not welding at the edge of the patch piece, the patch acts as more of a heat sink and tends to not melt away as much as seam welding on the edge of the patch.

We used to not wear a mask when we were doing these welds, just line up the tip and look away and hit the trigger for a second. The Hobart MIG welder I used had a "spot weld timer" that could be set for a second or so and then it would stop. Use the thinnest wire that will fit in your welder and practice to see how low you can set the welder and still have it flash off well enough so that it is melting metal the second the wire hits, but doesn't burn through the metal. It takes a bit of practice, but it is not rocket science. If you are a crafty guy, and have a decent welder, and you are not trying to weld to rust, you will make it work. Be sure to use seam sealer to encapsulate the bare metal so it does not rust out again.

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Doug

1987 300TD x 3
2005 E320CDI

Thank you riethoven, I will try your advice.

I'm using a Lincoln Welder, it does not have a spot welding timer, but I can do spot welds with it. I will try this technique one my next patch.

xp

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1985 190E 2.3L - a constant project.