I am about to have this bumper welded and my question is, should the weld be across the entire bracket or just half way as it seems? Also does anyone think there is any harm in having this welded as I don't know crap about welding chrome plated aluminum.

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83 300TDT BROWNBENZ
04 Sprinter

You may think we are ignoring you but it may be that you threw us a curve.... I went out to my 81 wagon with a magnet and the place it looks like your cut is is steel on my car. Are you sure you are looking at chromed aluminum ? Greg

It's pretty hard to tell what you are doing by the picture. Welding any metal is a matter of cleaning the surfaces to be welded, and using the right welding equipment and electrodes. If you take it to reputable welding shop, they can tell you what kind of metal it is, recommend a method of repair, and complete it for only a few dollars. I just got an upper oil pan (cast aluminum) 1 inch diameter hole repaired for $50 (which I thought was too high, but I forgot to settle on a price before he did it). I could have gotten a new one for $150, and a used one probably just as cheap as the repair.

Before weld repairing anything, you have to ask yourself what is the worst thing that will happen, if it fails due to a poor weld. In this case, your bumper may fall off. You have to decide if that is a risk you want to take, or purchase a new bumper. With a bumper, I would say it is a low risk. I'm not sure about what will happen to the chrome on the other side...can't tell from the picture if the crack is all the way through? Chrome may crack off during the welding of the parent metal. Again...the welding shop should be able to advise you.

Good luck.

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1976 240D
1987 560SL
2007 E320 Bluetec
1998 C280 (now son’s car)
1982 240D Manual - Sold

The only reason I thought it was aluminum was due to the corrosion that is present. It's not rust it's that white powdery corrosion. I brought it to a reputable shop today with a quote of 70-120. I think that’s fair. The weld is for the reverse light mounts so there isn't a worry of the bumper falling off. The reason for repair is due to the corrosion and the replacement cost of one of these bumpers.

Does anyone know of a treatment to stop aluminum corrosion? Something similar to a rust converter.

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83 300TDT BROWNBENZ
04 Sprinter

Do a search on bumper corrosion. I remember seeing a procedure to coat the bumper with some airplane anti-rust primer. It supposedly stops the aluminum corrosion. I tuned it out since I live in the rust free south.

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1976 240D
1987 560SL
2007 E320 Bluetec
1998 C280 (now son’s car)
1982 240D Manual - Sold

Aluminum will only corrode 1 or 2 molecules deep before aluminum oxide will stop the process. It's the black stuff you get on your hands when holding to an aluminum hand rail.
The white corrosion you have if the metal is aluminum is the result of electrolysis between two metals, in this case steel and aluminum with the added catalyst of saltwater. The only way to stop it would be to replace the steel with stainless, or aluminum. If you weld on the metal that is chrome plated you will cause the chrome to peel off. I have welded steel, aluminum, galvanized, stainless, in my old line of work as a sign installer doing large outdoor commercial signs. Never a car bumper, but the issue if electrolysis with steel and aluminum is a big problem in Florida. Mainly because of aluminum rivets being used to fasten aluminum sign panels to a steel frame. Near the beaches all the rivets would rot out in about 2 years. Stainless steel rivets would hold up, but were a pain to use. You could try cleaning the white powder off with a vinegar bath and then paint with a good two part primer (Mathews Primer, the greenish-yellow stuff) and top coat with urathane paint.

Thanks for the info. I found the "bumper corrosion" thread and am planning on priming and sealing the bumper when I get it back.

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83 300TDT BROWNBENZ
04 Sprinter