Rust bubble under weatherstripping - PeachParts Mercedes-Benz Forum

Capt Kirk · #1 01-15-2002, 10:23 PM

I was looking over my car for any minor rust problems since it has some of the worst paint known to man. And the worst thing came up, there's a spot under the rear window weatherstripping that has broken out with about a 1/4" by 1" surface rust spot. Is there something I could put over it so it doesn't grow any bigger until I get it painted (that'll be a LONG while). Or should I have the glass man come and take the window out so I can go in, sand the spot away, bondo it and spray a nice coat of primer on it?

ohcaptainron · #2 01-15-2002, 10:50 PM

I am currently restoring a 1985 300TD, I had a similar problem around the glass on the tailgate, before it went to the body shop I sprayed the area around the rust with a rust inhibitor that was over a year ago and the rust did not migrate or get larger, when I pulled the rear glass the rust had preforated thru the tailgate, I had stopped the rust on the outside but not on the inside, cut out that area and welded in some new metal, looks fine, I quess knowing what I know i would have fixed it as soon as I noticed it, it just wasn't convienent, just goes to show you they rust from the inside out not the other way around. Good luck!
Ron Mieloch
1985 300TD
1999 E300D
1999 E320 WAGON AWD

Capt Kirk · #3 01-15-2002, 11:02 PM

well thats not really an option, the closest to that is sand it away and paint over it.

Capt Kirk · #4 01-16-2002, 12:10 AM

Guess that leads to another question:

Should I remove the window myself, or pay some one to take it off and then later come back and put it in?

revray · #5 01-16-2002, 01:29 AM

Aloha Capt. Kirk,

I'm just working on a similar problem with my coupe. I opted to have someone from the local auto glass shop come to my home and take out the glass. (I have a rear window defroster so I made sure that he took care of the wires that connect everything up) What I found was that the bubble was the worst spot, but there were many more all along the bottom where water tends to collect, that were not visable while the glass was still in. Left alone, they would've deteriorated further. My primary motivating factor was that the rear glass for my car, should I have tried to remove it myself and broken it, is in the neighborhood of $1200. For me, it was wiser to pay the $90 and have a pro do it.

I fixed all the rust and spot painted. (I'm saving up to get the whole car painted) The glass man comes back on Thursday to put the glass back in.

Good luck,
Ray

1979 450SLC 102,000 miles
1980 300SD 199,850 miles

Capt Kirk · #6 01-16-2002, 08:20 AM

how'd you fix it?

by sanding it out out cutting it out?

tcane · #7 01-16-2002, 11:14 AM

I would suggest having a professional R&R the rear window because even with all their training and experience occasionally a window breaks. I've talked with the glass techs and they say M-B rear windows are more prone to breakage than others (some M-B rear windows are not one-piece). Also, they use large suction cups attached to the window to pull it out and re-install it. The suction cups will greatly aid the chances of a successful R&R without damaging the window. Also, the glass techs have all the special tools and knowledge to use them so if a problem arises they are best able to handle it.

I found good references for Harmon Auto Glass from insurance companies, AAA, and some folks who have experience with them. However, some members may not like Harmon (or their operation in your neck of the woods) or have their own preferences Whichever glass company you use, ask about their experience with older M-B cars and ask to have the tech with the most experience R&R your glass.

I second all those that suggest repairing the rust ASAP to prevent the further spreading of this gremlin. Also, this particular rust position probably means that water is entering the trunk - so take a look for the water trail and make sure the body drains are working to drain the water if any is accumulating. Look under the trunk side panel on the same side where the rust is to see if any water is accumulating.

Good Luck!
Tom

revray · #8 01-16-2002, 12:26 PM

Good morning Capt. Kirk,

I did both. Where it was only surface rust, I sanded. Anything that was more serious (which was most of it) I cut out the deteriorated metal and welded and riveted in new metal.

Aloha,
Ray

1979 450SLC 102,000 miles
1980 300SD 199,850 miles

engatwork · #9 01-16-2002, 12:27 PM

In the process of redoing the 240D I am planning on replacing the front windshield and the front/rear window seals. I stopped by a local, long term glass shop and he gave me an estimate of $200 (includes installing the new seal) to install a new front windshield and $75 to replace the seal in the back. This is with me supplying the seals. I will probably take him up on it because the way I look at it if he breaks the glass then he will replace it.

Palangi · #10 01-16-2002, 03:05 PM

Just going through this same thing now on mine. Refer to the recent thread entitled "Pop" on diesel forum. I had what looked like a minor rust blister peeking out from under the rear window gasket. When the old glass came out, the little blister turns out to be connected to a 1/4 rust hole under the gasket. After wire brushing the rusted area, it became a 1/2 inch rust hole. Over the last few nights, we have done the bondo thing, the paint / let dry / sand / paint / dry / sand thing, and the lacquer thing. It won't be real pretty ( trying to match faded metallic paint ), but it should be functional enough to get another 5 years or so out of the car. New window is going in today. Will see what it looks like when I get home.

As far as taking the window out, I would think that what puts the window at risk of breakage is trying to save the gasket for re-use. If there is rust, it probably means the gasket is no good anyway. ($90). If that is the case, just cut the gasket with a box knife to free up the window completely.

Funny thing on mine is that this is was the only rust spot on the car (except for the front edge of the muffler).

Capt Kirk · #11 01-16-2002, 08:00 PM

I got new Windshield gaskets when I went of my parts spree.

I took a peak under the gasket today, I didn't see a hole of any sort, it's just eating through the metal. I'm going to try and get some one out here and take out the window for me to fix it.

Should I bondo it, or take it to some one to cut it out and weld in a new piece?

Palangi · #12 01-16-2002, 08:59 PM

I have a feeling this rust hole may have started out as a drain hole. The reason I say that is because there are a couple of other perfectly round holes spaced at odd intervals in the lip under the gasket. I dabbed some primer on them, hopefully to help keep rust from starting on the edges. Now that the glass is in, my shadetree bondo and paint work looks a lot better than I expected.

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